I'll be very interested in hearing what JB has to say about his experience when he has time to gather his thoughts and elaborate. Very generous of you to offer that opportunity RP.

Yes, and I knew you would be very curious to see how this all went. It is a shame that you don't live close enough to experience your own evaluation of my audio room. It would be nice if you were able to do that.

From my stand point, things went very well and it was a great day. JB is a very knowledgeable person, and most certainly on a very high level of understanding when it comes to audio and room acoustics. He is a great guy to know, and someone that you can trust to give advice. A good friend to say the least.

As for what he might say about this event, time will tell. I don't know that he will say anything, although I have a feeling that he has plenty to say about his experience. So that is up to him. I think he needs a couple of days to get his thoughts together and make sense of it all. I do welcome him to offer his thoughts about his experience, so you shall just have to wait and see.

I will get the return privilege of experiencing his audio room next spring. That should be interesting as well. I will say from my perspective, there was a great deal of thought going on inside of his head. It will be interesting to get his viewpoint.

Keep that dream alive my friend!

Thanks for taking the time to share your thoughts with us JB. Glad you got the chance to have some fun and venture deep into a unique musical experience as well as share some comradery. Pretty cool that you'll be offering the same courtesy of a listening session to RP. It's nice that you'll both have a perspective into each other's listening environments.

Looks like the session sounded great, albeit initially the smaller space made it difficult to perceive a very wide soundstage. However, I'm sure the extensive room treatments made it sound as good as it possibly could be. My room is on the smaller side as well (actually almost the same as RP's but with a 10' ceiling instead of approx. 8') and I know how challenging it can be.

I thought RP's custom speakers looked phenomenal and glad you confirmed they sound just as amazing as I imagined. The build is second to none. Glad the sound is as well.

You mentioned that once the C-9 was engaged, the room took on a whole new dimension. Besides the room treatments, the C-9 sounds just like what the doctor ordered for a room on the smaller side. From what I've read about the unit I expected nothing less but I'm sure each room can help or hinder the effectiveness of such a component. Glad you found it to be an exciting and worthwhile addition!

Thanks again for the perspective JB, and congratulations RP on a great system and listening environment.
Cheers to you guys and many more great listening sessions.

I was not sure what "C-9" referred, and found this:

"A C-9 in audio refers to a specific type of microphone preamplifier.

It's a vintage piece of equipment, known for its warm, rich, and often slightly distorted sound. The "C" likely stands for "console," as it was originally designed for use in large studio consoles. The number "9" is a model designation"

Is that correct?

Thanks to all that replied and your input is valuable.

Thank you JB for your honest opinion concerning your listening evaluation.

Although we are a bit apart on what you and I get from this room in a couple of aspects, it has to be expected that for many reasons, none of us ever see or hear things identically, or in the same degree of "absoluteness".

I can tell you this, I bent the law of physics as far as one could ever expect too do while confined to limited room dimensions such as what I am forced to deal with. Like many others, my options are limited, and I have no other choice. We simply have to make the best of what we have and learn to accept that reality. If I were to take all of my acoustic devices down to the much larger fireplace room downstairs, taking advantage of that more ideal space, then naturally, just by getting closer to golden ratio dimensions alone would make a huge improvement. That is not going to happen in my house as long as the wife has anything to say about it. I have thought about this so many times, but always knew it could not happen. If I were single, this would have been the audio room setting from the start.

So yes, It is hard enough to make a room my size even remotely good for music, let alone making it sound like a huge open space. If you want a huge open space, set your equipment up outside and your problem is over. Not sure how long that would last with the neighbors. It would get old very fast having to keep bringing that equipment back into the house after every listening session. But if you expect the best outcome, that is the only true approach to a completely natural and untainted soundfield. No need for acoustic treatment in a natural setting.

If anyone fails to understand why I went to such great lengths with the acoustic treatment in my audio room, the answer is obvious and absolutely necessary to make a room with almost square dimensions transform into something acceptable, let alone high end. I guess I found my "fulcrum" between these two points as a leverage of balance where I can live with it and be content. Without this extreme level of acoustic transformation, this room simply could not be used for music.  It is pointless to design a perfect racing car only to drive it on a washed out dirt road full of ruts and holes. The results are very limited and nowhere near ideal.

If you had heard how terrible this room sounded before treatment, you would understand exactly just how much I improved this room with what I did. Yes, there are limits to boundaries and perception of space, and every room is going to be bound by those limitations. As stated, we are governed by the laws of physics which we simply can't magically influence. The difference is to make the space within your boundaries sound comforting, and in agreement with what you hear WHILE understanding those limitations.

I am more concerned with the element of natural sound that freely expands in all directions "within" these understood dimensions where so many acoustical conflicts come into play. The acoustic war is a tough battle to conquer. There will always be limitations and compromise within any listening room, no matter how well designed it is. Like I said, if you expect perfection, then you better take it outside.

My main concern is the control of room modes within this almost "impossible" room size. As you know, a square or round dimension is the absolutely worst case scenario you could build from.  I corrected my situation by virtually "removing" the walls with acoustic friendly "walls" which actually work in harmony to reduce the effect of standing waves. As I told you in the past, my revised room dimensions fall well within Bolt's range. There are rooms much larger than mine that don't even do that! Volume is not the whole story, it is the actual dimensions that make the difference in controlling a reasonable degree of decent acoustics. A room like mine requires a massive degree of absorbent while at the same time having to make sure the room isn't rendered acoustically dead. This is the absolute worst situation to engineer and do it right.

I want to make a note concerning the latest room change I made prior to the listening evaluation.  I had no time to evaluate this addition prior to the listening session. I really had not the time yet myself to evaluate the change.  My observation is this during the time JB was listening to the new setup. I sat in a location at the farthest rear point in the room (NEVER RECOMMENDED DUE TO BASS BOOM), sitting up on the ternary diffuser platform about three feet above the normal listening position, directly behind the perfect listening "apex" sweet spot where JB was at.

I quickly realized that from the time before I added the final sidewall absorbers and the huge binary diffuser at the front of the room just before this visit, this area used to sound very muddy and quite awful at the rear of the room. This is normal in any room due to the characteristics of standing waves in a room.  **Note: this is why the 38 percent rule is so very important, and so very accurate in practice. I have proven this concept to hold great weight within its theory. The worst areas are always going to be at the front of the room, the rear of the room, and the center of the room. You always want to avoid those areas at all costs.

The negative aspect of this change which I now realize, the sound-stage is restricted as a result of the massive sidewall absorbers I just placed in the room. I lost the needed reverberance that was responsible for the wider sound-stage and sense of "space" that I was accustomed to before.

This is counter productive to the very reason why I placed these there in the first place. The intent was to eliminate first order sidewall reflections which smear the timing in music, and also place a veil upon the perception of that actual space. This should have increased the perceived degree of spatial imaging. What JB has detected, and now with my listening tests conducted since he left here, have brought me to the conclusion that what I heard before, and what I hear now are NOT the same degree of spatial expansion. The sound quality is great, detail and bass response is superb. I am however baffled as to this outcome. The only thing I can conclude is that the addition of these massive wall absorbers actually killed the robust reverb factor with over absorption. This just goes to show how easy it is to go too far with room treatment, or not implementing the correct acoustic treatment for a certain target area.  This really is a double edged sword that can cut either way. My conclusion to this test is that I was better off without the sidewall absorbers.

So, getting to the point with the latest acoustic additions. I expected this area where I sat in the rear of the room to be a "less than acceptable" spot to enjoy the music. That is why my listening chair isn't placed there. But that night, I was amazed to discover that not only did this area sound reasonably good now, but I was clearly hearing the robust presence of spatial detail at every point around the room, including an area that seemed to be at least three feet behind my head. ( and I was sitting behind JB's sitting position in FRONT of me! ).

Why is that anything special you may ask? Because my head is placed directly against the hard surface of the huge diffuser I am sitting against. There is NO space behind my head at all.  So you see, the space DOES actually extend beyond the physical restraints of the room dimensions. This may not become clear to you within a very limited degree of listening experience in this room, or within a very limited degree of musical variations which may, or may not provide the material needed to convey the extensions, or limitations, within the musical soundfield as portrayed in the recording. You can only hear the recording the way it was produced. Many recordings sound flat and restrained, no matter what the room situation is. They were produced to be heard that way. When certain phasing effects are purposely implemented within the musical canvas, then that is when it should also be conveyed within your room in that same degree as long as the acoustics are good.

We also have to consider our hearing limitations and variations of perception between one listener and the next. We simply do not all have the same degree of hearing potential, nor the same degree of perception. I guarantee you that no two people on this planet have the same hearing characteristics.  I would love to have a couple of young people around twenty years old listen to the same thing we were subjected to in this room. I think the results would be quite interesting in regard to my statement concerning auditory fluctuations between all humans. As we age, our hearing suffers tremendously through that progression of time. Even though the critical factors of music are within the 40Hz to 8 kHz range, the range which extends to perceive the delicate nuances of higher frequencies ( specifically the "air" factor ) are well above this frequency range. The critical harmonics that make up so much of what defines a great audio system are also within this higher range. Most men can't hear much above 14 kHz after the age of 50. Many can't hear above 10kHZ. That is just the facts of life. Anyone that thinks they have much better hearing than that needs to take a professional audio-gram in a booth with actual test equipment. I think you will be shocked with the results.

I can assure you that a young person under the age of twenty can hear everything that lies within the music. They are the one's who are truly qualified to know just how good a music evaluation really is.  I know very well that I no longer have this upper range of hearing. The last audio-gram I had from an official testing center was at the age of 32.  I am proud to say that the tester was surprised at how intact my hearing ability actually was at that age, as that is certainly not typical. Even at that age, with well protected and preserved hearing, it is expected for a male to have a range limited to usually no more than 16 kHZ, at best.  Take into consideration, dangerous noise levels resulting in premature, and permanent hearing damage, and this affects many of us even more than just natural age degradation alone.

I had an even balance which clearly ran strong to not only 16 kHz at that time, but with some extension up to 18 kHz which is simply remarkable and rare. I expect that if I were to test again now, I would be restricted to 14 kHz or less "best case" scenario. If you can top that at the age of 63, then you are one very lucky individual to say the least. A professional audio-gram is the only way to prove it. I remember having to actually hold my breath just to make sure I could register the delicate faint signals that were played with the headsets. I would not have heard those upper limit registers if I masked it with my breathing.

My point of this is to support the fact that our hearing potential is what actually governs our perception of quality, space, and time.

I can assure you that the limitations of being denied the upper frequencies are in direct relation to what can be detected in a "spatial" environment.

Just a simple fact of life that can't be denied. I wish I had the hearing potential of a sixteen year old. If I had, I know there are many things going on in this room that I just can't hear. And with age, that factor only declines.  And that is where the laws of physics really apply.  This is why that I understand my limitations, knowing that my limited perception is not entirely reality, only a certain "portion" of the whole. I can only offer my opinion based upon what I can detect, nothing more, nothing less.

And of course, we could get into the shapes of the human ear, and all of the variations which makes everyone unique in that form. Like the fine tuning of a delicate instrument, the shape of our ears and the structure within that complex are in effect, bound to the degree of "tuning" that nature gave us at birth.  There are some of us who are born with perfect pitch. Many others are not. So many variables, so many degrees of separation. I always think about the situation with Beethoven. One of the great masters of music, with his greatest works created within a world of deafness. I see that comparatively as a world class racing champion who just happens to be blind!  Some things in life are just plain defiant within reality, yet so amazing within the outcome which can't be denied.

Please do not take this personally, this is just the card life has dealt us whether we like it or not.

In the end, we all have opinions, and we all have different degrees of perception within our visual acuity, or our auditory acceptance. The result always leads to a debate it would seem. Sometimes we just have to "agree to disagree" and accept that. Just be happy with what you have and everything is just fine.  I know that I for one am very satisfied.


Now, leading on to something much more interesting at this point in time. There really is something special about the Carver C9 Sonic Hologram Generator. As JB now himself has had the newfound experience with what this unit offers at virtually very little cost, is yet another defined moment  in which to suggest that this circuit warrants a new life in which to enhance the quality of our music.  I believe this is the time to reintroduce this circuit to the audio community and do so in a refined upgraded version that makes the cut for audiophile grade.  There is not a more effective means at such a low cost to rectify the horrible restrictions which cross-talk creates from stereo speakers. You only have to experience it to really understand and appreciate the huge improvement offered. If a 45 + year old stock unit still in original form can provide this factor of acceptance, just imagine what an upgraded version with high quality parts could do. This circuit warrants all 1 percent precision components due to the required balance of the circuit to work effectively as intended.  MADE IN THE USA....and there you have it. That was the America I remember. The chips are still available with better quality alternatives from Texas Instruments as an upgrade. Installing a higher grade transformer and audiophile grade caps will certainly make a difference. My conception towards a new upgraded version of the Carver C9 would have the push button controls removed and replaced with a variable means such as stepped attenuation for both the level of "Injection Ratio" and the width of the spatial generator. With a wide range of accurate stepped positions, the degree of tuning is extensive and precise with far greater control, with full accuracy across a much wider degree of precision.

My goal is to focus upon the creation of a modern day upgrade to the original Bob Carver C9 Sonic Hologram Generator.

NOTE: Bob Carver was removed from his own company during the late eighties. Imagine that, being fired by the board of directors from the very company he built, and provided careers for those very same A******S that forced him out!  The products that Bob created before he left the company are not the same ones that were cheaply built overseas during the latter years into the early nineties. That crap was nothing but cheap knock-offs that destroyed the Carver name.  Please be careful if you ever consider any products made in the latter years. I don't recall the exact year of his exit, but I am thinking around 1988 or 89.

Bob went on to create the company SUNFIRE, which was a major step forward in direction for him anyway.  I owned the huge mega Joule surround sound amplifier (Sunfire Cinema Grand) that he designed after that company came about. I can tell you that this amp was a major leap forward in design integrity and quality. The power that amp produced was incredible.  I believe it cost me somewhere around $5500 back then, and it only came from authorized audio dealers who strictly carried high end esoteric equipment.

You can't keep a great creator down! He is a brilliant physicist who gave us many great designs in audio back when the likes of the mainstream were dominated by the likes of Pioneer, Kenwood, Marantz, etc. Whether you liked his inventions or not, you can't deny his ability to pioneer great ideas way outside of the envelope.

Do not ever underestimate the quality or integrity of the products he created. He being a genius, which the mainstream failed showing him the credit he deserved.

DOES THIS GUY SOUND FAMILIAR? Seems there might be another audio creator with very similar talent. Perhaps you have met him.

I respect anyone who dares to think outside of the box, and doesn't hold back against the norm to bring us new and innovate ways to improve our lives.

With that said, my Carver C9 that I just acquired is indeed an original version that Bob had control over. This one is authentic. Be careful of what you buy in his name. Mine was manufactured in Lynnwood, WA back in 1986. Still works perfectly today!


So, moving on: I came up with a rendered image showing you an example of what I have in mind for a new revised model showcasing this concept.

 I may start a new thread in the DIY section to get this idea off the ground and into action. This would be a great concept for Steve to consider using the premise of the circuit technique, and upgrading it to audiophile standards which Decware is known for. This unit could be offered with a signal tube upgrade replacing the five opamps in the circuit. For a budget friendly version, a standard model using new Texas Instrument OPAMPS could be offered. The tube version would be an upgrade for an additional fee. The idea of using stepped attenuators to control the levels of the circuit are paramount in my logical opinion. This could be created in a way that makes this unit unique and every bit as good as the original design, only better and not have to worry about copyright infringement. An altered version of a patented design that old should not be a problem.

I think that a poll needs to be started to gain positive interest for this to come about in the future. It should be clear to see that a unit offered like this would have incredible interest with huge sales potential in the audio world. Anyone who understands through experience what this device brings to the table should agree with me on this without reservation. Just ask anyone who has owned this design in the past. The results are very favorable. Just my two cents thrown into the kettle. This however is one vision that should not be overlooked.

Perhaps a poll could be taken to see how much interest there really would be in this unit. It would be interesting to see how much people would be willing to pay for this unit being offered with custom options. I will tell you this, I WILL BE THE FIRST TO ORDER this unit if Decware ever brings a device like this to reality! The cost is irrelevant considering how important this device is to me.  Knowing that Steve has control over it's design, that already becomes the selling point for me to buy it. You have to consider what this device does for any audio system. You also have to consider that to the best of my knowledge, there are NO competitors which have anything like this in existence. This makes for an ideal opportunity to create something new and innovative, which I know would gain popularity very, very quickly among the audio community. I can only suggest it, Steve has to make it happen. If you think this is a good idea, then let Steve know you are interested and make it happen!


I can envision two offerings of this circuit. Perhaps a new Torii amplifier which incorporates this circuit as a whole new concept model. Finally, the only amplifier in existence which has the ability to STOP crosstalk-interference cold in it's tracks, without tainting the purity of the amplified signal.

Combined with a class A SET amp, this would be a perfect marriage and a wonderful concept.

Then of course, a stand alone unit with options that can be used in any audio system. This unit goes between the outputs of the source and the amplifier.

This would expand our audio horizons further beyond the envelope edge with a breath of fresh air.


Here are a couple of images which represent a design I have in mind. These are fictional and are only a concept. Let me know if this interests you.








As for optional stepped attenuators which really should be standard in this device for optimal control, this is a good option.






Something of this caliber would be interesting for a new design standard with this unit. Expensive, but referance quality where cost is not a factor.





Or something such as this for dedicated controls???





Anyway, just some audio food for thought.

Make your vote known. WOULD YOU PURCHASE SOMETHING LIKE THIS CONCEPT?   YES or NO

I got a C-9 in transit. Hope it is as clean as yours RPS. I do agree with your sediment of this device. It truly fixes a problem with stereo systems. One problem that is always present no matter the system - if it has 2 speakers. No hype just bare facts.

You should talk to Albert at SpaceTech Labs.  I actually own the passive preamp
https://www.thebestamp.com/IR_Remote_Volume_Controls/RV-1003.php

Which is very similar to your rendering except it uses a AC/DC adapter instead of batteries but it would be a very easy to replace it with battery.

I would consider buying a Decware version of the C-9. Not sure what the price point would be but if it was a stand-alone unit for my purposes that would be the ideal. As long as it would fit appropriately in my chain somewhere I'd be willing to give it a shot. Using tubes in parts of the circuitry would be the Decware way and probably the option I'd prefer. With everything on Decware's (Steve's) plate, it might be a long shot, but we know how Steve likes to come up new products/concepts once in a while and maybe this would scratch an itch for innovation as well as provide a new product to continue unique and future sales. We'll see where this goes.

Also, nice experiment with the speaker cables. Seems like they may be working out nicely and with some tweaks might give you the frequency range you're looking for. There sure are a lot of variations on a theme when it comes to cables of all kinds. I agree that air is a great insulator. I have some speaker and IC cables that implement to some degree what you're discussing here. The speaker cables use stranded OFC copper to make up each individual conductor and each one is then either coated with silver, tin, or left pure copper to deliver the proper frequencies to the speaker. The cables use air pipes within to isolate and insulate the conductors from each other (high pair, mid pair, low pair). It was an intriguing concept, and I just had to try them. I'm very satisfied how they perform in my system and can see them being used for a very long time. Seems to be something to float everybody's boat and that's the fun part about this journey.

Cheers and let the journey continue.

Oh, BTW:



Hey JB, I almost forgot to congratulate you on taking that step purchasing the Carver C-9. I don't have to reassure you there will be no regret, because you already know that.

Very glad that you have one now.

Happy listening!

I am still waiting delivery of the c9. Yours in your space was impressive and leaves a mark that compled me to jump on the old band wagon. Your description prior my session was tantalizing. It seems like it will fill a void in my room that the stereo setup creates. We will see how it plays out!

Here is a link to the c9 Facebook page:

https://www.facebook.com/groups/954028525368313/?ref=share&mibextid=NSMWBT

I really think that the c9 circuit could be placed on a chip these days. If you found an enterprising chip designer to etch a copy and then get it manufactured, I think there would be a better chance to get Steve on board

Finally got time to reset the Charoit accommodating the Carver C-9. Using Carver and RPS recommendations along with self intuitive workings, the result is a huge step up towards the grail.




Hey JB,

It is like looking into the mirror for which I see my own journey expanding with the Carver C9 Sonic Hologram Generator in the loop. Your discovery within your own listening environment very much confirms what I have been saying about this unit all along. As more people seriously evaluate this very critical device within their own systems, the more this unit and it's so important function become the truth which can't be denied. More and more people will begin to take note, and want to discover this "correction" within the music as experience takes hold in a very convincing manner.

I for one will never be satisfied with the regular way of listening to stereo, with its deformed "out of focus" picture which most people have always believed to be the norm. Every since I heard the difference many years ago in my youth, the truth was revealed regarding what I hear without this correction. I have always missed the dramatic change which the correction provides, never really satisfied without it.  Now, you and I both have what it takes to reveal what we all should be hearing with our systems. The musical canvas simply is not what it should be without it, not even close.

People talk about hearing three dimensional imagery within their rooms without ever knowing what actually can be revealed with the proper corrective measures. If they only had the experience which you and I both understand very well using the C9, then, and only then will they discover the natural epiphany within their minds,  the standard of reference for what true imaging really is.

This is not a new concept, as this problem has been known since stereo evolved. Many types of remedies have been considered or tried over the years. Even the master of acoustics himself, Manfred Schroeder, knew of this anomaly, and conceived measures which to correct it. There have been many attempts by different manufacturers throughout the years.  The truly successful device is one that is affordable, simple, and absolutely effective. That of course is the Carver C9. It only has one purpose, that being the elimination of interaural-crosstalk, and it does it very well. And to think, this device has been around since the mid eighties! It has been mostly forgotten and lost in the shadows of the audio world.

It is time that people rediscover what this is all about, and find out what it can do for them.  Many will be very pleased to discover the truth within the music they hear. You have to hear it to understand it, period!

No amplifier or DAC, or any other device will ever come close to what this simple device will do to bring the focus of music inline within a natural perspective as perceived outdoors in real time. With this device, your system will now shine to far greater levels of quality sound imaging and clarity. This truly will be the greatest upgrade you could ever imagine to experience.  This does hinge upon proper speaker type, and arrangement. The result also is dependent upon proper room acoustics to start with.


It is easy to understand what this reveals when we use nature as an example of this audio truth. As you may recall, I painted a very clear picture of what one hears in the middle of nature. That being how easy it is to naturally perceive the exact location and distance of every sound that you hear around you in a full 360 degree setting. Being able to not only decode these coordinates easily, but to pick up on every one of them simultaneously with pinpoint precision, and clarity, in time and space.

You also reinforced the very factor which Bob Carver made clear about the importance of proper speaker arrangement within the room, and how vital acoustic measures are to support this device for the best possible outcome. If not set up properly, the correction factor will be minimized and non-effective.

It is critical for the speakers to be in close proximity, with a very precise apex aligned to your ears. As a minimum, the room MUST have a minimum degree of acoustic treatment along the side walls, and directly behind the speakers to reduce reflections in those critical areas. Absorbers placed just in those areas alone will make a profound difference with this unit activated.

You noted through experience exactly what Carver stated in the manual about setup, and why there are two degrees of injection ratios available(normal & theoretical), as well as two degrees of aperture settings (wide & narrow). You echoed what he said regarding the preferred setting of these choices. He stated that with full room treatment, the normal setting set at the narrow aperture will be ideal. He also stated that with a non-treated room, or a room with minimal treatment, the listener would most likely find the need for the theoretical setting set at wide aperture to be more effective and ideal.

Going back to your listening experience within my room. You stated that the theoretical setting with the wide aperture was "gimmicky" to your ears, finding the normal injection ratio with the narrow aperture as acceptable, and just right in your opinion.  Now remember, my room is completely treated acoustically.

Now, in your environment, we are now considering two completely different listening situations. You have less acoustic treatment, and your room reacts differently than mine acoustically simply from different dimensional aspects. This is why the same piece of audio equipment never sounds the same from one environment to another.

So, what you just disclosed was now a totally different perspective going from my room to yours. Now, everything is reversed within your environment concerning the degree of injection ratio vs aperture setting. Now you don't find the wide setting to be "gimmicky" at all. You simply have found the need for it to be used.

What works for me does not produce the same result in your situation. And this is exactly why there needs to be both settings to balance things out from one type of room to another. Bob knew exactly what he was doing when he designed this unit. It is really too bad the importance of this device never gained the recognition that it deserved.  Just be glad that you were fortunate to have discovered this and make it work for you.

For me, this device was my audio "salvation"!


I am glad to know that I made a difference with at least one other audio enthusiast who truly appreciates what this newfound corrective measure will do to heighten the levels of musical purity and naturalism.

With your affirmation in two different listening sessions using this device, you are now well prepared to understand through experience just exactly what this is all about. This is the very thing that will motivate others to discover what you yourself have recently learned. My assumption is that you will not be the last to place one of these units in the audio system. If what you just clarified through your own experience does not motivate people to investigate this, then I doubt anything ever will. That is a shame. It will be their loss.

I congratulate your efforts to dial in the room setting, and trying ALL settings until the correct balance was found. Many will never do this, and just say that the unit doesn't do much for them, simply because everything is wrong in the setup. As you discovered, everything hinges upon proper set-up.


I don't have to wonder what you are experiencing, nor do I have to wonder if you are satisfied. I already know what the answer is on both counts. But then again, I never expected otherwise.

It is nice to know that I am not alone in this adventure. We can easily relate to the experience we both are achieving within our listening sessions. At least you really do understand without question where I am going with this, and why.


Anyway, I am going to be very busy for some time with the start up of new projects.

I just received delivery of parts from Mouser Electronics. I ordered every part needed to completely build a new hologram generator from scratch. All resistors are Vishay metal film 1% high grade. The electrolytic caps are all Nichicon, and the film caps are Vishay 5% tolerance or tighter. I bought enough gold plated IC sockets to build two units. I bought enough high grade OPAmps to build three units. These are a major upgrade over the original stock chips. I am using the Texas Instruments RC4136N OPAmps for the new build. The switching diodes are being upgraded to high speed versions of higher quality.  The JFETS for positions Q1 and Q2 are also upgrades of higher quality.

I plan to use a toroidal coil transformer for the power supply. A switched IEC will be installed with built in power fuse.  For now, I might simply employ three toggle switches for the controls. I want to upgrade to an advanced use of attenuators versus the two way switches for precise control of the levels. That is going to be a challenge, so not sure how to go about doing that for now.

I am drawing out the schematics now so that I have a clear picture as to how I will solder all of the components point to point. I will not be using a PCB. For the chassis. I am thinking about converting a Tascam cd player chassis for this. I will simply remove the faceplate and custom build a new one from metal for this use.  

I am also looking into a new diy DAC build based upon the Texas Instruments OPA627. That is the chip I am using now (actually two since these are one channel design). I really love the sound quality of this chip and I think it is a wise choice. For some reason, this is by far, one of the most expensive DAC chips available, with the Wolfson chip used in very expensive high end players being close. These chips are outdated, but the opa627 is still available from Texas Instruments. The Wolfson chip is not. I will need two of the opa627's @ around $35.00 each!!! Most DAC chips produced now for this purpose can be purchased for around 2 to 3 dollars. I want the old 627 chips, and will go with that unless something else comes up that I like better.

The plan is to integrate both the DAC board and the hologram board within the same unit. Just have to wait and see where the direction of the DAC build will go for sure.

But I now have everything needed to build a new upgraded version of the C9 except for the transformer and switches for the controls. I have to figure out how these toggle switches will be wired where the old push style buttons were used. Just have to find which pads switch from one section to the other for each switch direction.

I am also underway in the design of my next generation of speakers. These are based upon the original Jensen ULTRAFLEX designs from the 1950's.  In the past, I built a set of the Decware version of these Jensen designs you know as the NFX (ultra-flex). I remember having an intense relationship with the way those speakers sounded to me. They were just about the most natural sounding speakers I ever heard. I found them nearly perfect .  

So thinking back to the experience I had with those, I thought that they would be a wise design to consider again. I am going to duplicate the original 1950's Jensen enclosures instead. I have a good feeling about the outcome with the drivers I intend to use. Ultra high efficiency and superb imaging. The full-range Tang Bands will be perfect for the main enclosures. The bass units will be separate, also built to the design specs of the Jensen ultra-flex 15 inch woofer enclosures. My new Eminence drivers with 99% efficiency @1w will be used in those.  I will not be starting the speaker builds until next year as things are going now. I really want to focus upon building a new C9 clone, and focus upon upgrades to the DAC for optimal performance. That will be long term project as well. You heard how good my current DAC sounds. I am in no rush for upgrades yet. But I do have plans for it in the future.

Again, congrats on that new C9! Thanks for that valuable input which others may find interest in.

Enjoy the music, you have a great deal to discover with this new device.


So if I am absent for a good while, you know that I am up to something. You will hear about it in the future.

And of course, I still have all of the in house remodeling projects that have been put on hold. I have to find time to work on those in between.  I will not be bored this winter.

JB,

Thanks for your impressions of your new Carver C-9. Sounds like with some room refinement you really got it to shine. This really validates RPS's assertions of what it can bring to the table. (not that I didn't believe him, I sure did) but nice to know it's repeatable in other folks listening environments. I looked for one when RPS first mentioned it but really couldn't find one, or at least one that looked reasonable to take a chance on. After all, most are older and just not sure how well taken care of they were. Anyway, glad yours was in good shape and is performing well.

RPS,

Good luck with your new audio projects. That's some high-level stuff right there. Pretty amazing you'll be tackling a new hologram generator (from scratch no less) and DAC, possibly integrating them as one seamless unit. That sounds pretty cool. I bet they would sound great on their own (if you create them that way) but combining them would probably bring it to an entirely different level.
Again, good luck with these amazing builds and your new speaker design.

Wow RPS, thanks for looking out for me!

Looks like I'm joining the club with you and JB. That unit should arrive in a week or so!

Looking forward to seeing how it fits in my system. I have very little leeway as far as speaker placement is concerned but should be fun to experiment.
I didn't even ask if there was a manual with it, decided to just fly by the seat of my pants. (based on the pictures I doubt there is a manual but for the price I couldn't go wrong)

Thanks again for pointing me to this.

Looks like I'm joining the club with you and JB. That unit should arrive in a week or so!


Congratulations!!!


I am very pleased to hear that you jumped on that unit. I saw another one last week for the same price. It didn't last long either. That unit also came from an estate sale.

I am pleased to have helped you find something special without breaking the bank.  I do hope that you find this unit as satisfactory as what I and JB do in our two different settings.

One thing that you will want to change later is the RCA jacks. They are not the best quality and large RCA plugs do not fit as well as they should like the Nuetrik brand I use. You can order a set of Nuetrik chassis plugs from Parts Express and the gaskets for just a few bucks each.  You simply need to un-solder the connections, lift out the existing RCA jacks and reinstall the new ones. It will be worth it.

You can use it the way it is now, but this is something to upgrade later on. If you have the slim type of RCA plugs, then no problem.

I have found in my room that setting the Hologram injection switch to the NORMAL position, and using the aperture ratio at the WIDE setting works best for me. I now have dialed in my speakers to very close proximity which is ideal for cross-talk elimination to work optimally. I took the speakers out of the bass extension pods and set them directly onto the floor with only about 36 inches between driver centers. The toe in is minimal at only 3/8 of an inch offset at the rear. This has made a tremendous improvement over what I had set up when JB was here. It is too bad I did not have this set up this way before he got here.  That is the whole part of experimentation. You never know what's best until you experiment. With the new speaker cables and this refined setup, I am truly amazed at what I am enjoying now....just makes you sit there with a crazy smile and complete satisfaction knowing that you did it right.

The system is warmed up now in the audio room. It is time for me to go up now and spend the night in audio bliss!

I would advise you to try everything possible with the setup. Try all combinations of the hologram settings. You may find that something different than what I am using works best for you. I would be surprised if you did not get immediate affirmation for what this unit does to your music...that being once you set it up correctly.


As for the manual. If you don't get one, I believe you can download a PDF file of it. The service manual download is also available for free.  If you can't find it, then let me know. I will send you the manual.

Okay, the music is waiting on me...gotta go!


Enjoy that new C9.

I would venture to say within reason that the "C" designation logically represents the Carver name. I am sure that you knew that, just making a joke. But hey, sometimes the obvious isn't so obvious!



So now there are three of us that can understand each other when we talk about the holographic stage created with this unit. At least mrchipster will find out soon enough. I am looking forward to his findings and impressions once he experiences this unit.

Don't know if 4krow is still around on these forums, but he has extensive experience with the C9 unit. I am sure that he could add plenty to what this unit provides. There are others around with past knowledge of this device, they just don't chime in.

Anyway, I hope mrchipster gets a unit as nice as what we received. Being this came from an estate sale, sounds like it took passing on for the original owner to part with it.  We are all getting there soon enough.


BTW:  mrchipster, I cleaned all contacts and thoroughly treated with DEOXIT cleaner, plus the gold treatment when I got my unit. The spades on the power cord were tarnished from age. I cleaned those spades with Emory cloth until shiny again. After all of those years collecting filth, it is important to clean everything thoroughly for proper signal contact. If you don't have DEOXIT, just use some isopropyl alcohol to clean the contacts.

I don't like the way they used those inset RCA jacks.  I plan to upgrade my unit with much better versions that my cables can connect to securely and fully.  The Nuetrik PRO-FI plugs do not fit this unit like they should. The connections still make contact, but not what I find satisfactory for a firm positive connection.   I would say that with age, these RCA terminals most likely have less than ideal surface contact anyway. Surface corrosion does take it's toll. If you are not one to use a soldering gun, then don't worry about upgrading. It will work just fine the way it is. A good cleaning is absolutely mandatory though.

So let us know how this works out for you. I think the results will be interesting.


JB, don't worry about the work that is piling up. You will get there eventually. Just have to make priorities and take things one at a time. You always need to make time for music. That fuels your inspiration and motivation for everything else. Trust me, I am in the same boat as you are. Every day brings progress.

Thanks JB and RPS!

I'm looking forward to receiving the unit and playing around. I had seen one at a reduced price of $75 (from 150) a little while ago but the pictures made me pause (looked too beat up for me). I'm glad you saw this one and let me know about it. The pictures and the seller's feedback gave me confidence to buy (as well as coming from an estate sale) so I had no problem paying a higher price to try and ensure a higher quality unit hopefully. These things are older so it will always be some type of risk I think, but worth it.

JB - glad you were able to have some time to sit and listen for a while. It's always good to take a little time to relax between projects. You seem to keep yourself very busy.
I'll be looking forward to that 'life size' soundstage you describe. Right now, I'm getting the best sound I've ever gotten in this room by way of room treatments, tweaking, and lots and lots of time (10 months) finding the right speaker position for my environment. I get a great phantom center channel, and the sound goes wall to wall (left/right) most of the time. Even though sounds come from the left or right area they don't seem to come directly from the speakers. Just a nice separated and distributed soundstage from left to right, making the speakers disappear for the most part. Two things are lacking though. The depth and height of the soundstage. They are not what I'd like them to be and so I'm looking forward to seeing if the Carver can give me more of it.

Because of how I must set up my room, a credenza between the speakers housing my components across the top, and limited ability to push the speakers closer together, I'm not sure I'll be able to get the full effect of the C9 but if it even makes things a little better than they are now I'll be a happy camper.

I've downloaded the C9 user manual and have read through it. I have ideas and things to try once it gets here so it should be a fun journey.  

Also, glad to hear your plan is falling into place and new steppingstones laid to carry you forward. Enjoy the holiday season.

RPS - Thanks for the tips on initial settings for the unit and insights into cleaning and potential RCA upgrades. I will certainly be going through the unit as thoroughly as I can. The RCA upgrades will definitely be on my radar in the future.

I will certainly keep you updated as I take the C9 through its paces in my space. Should be a fun trip!

Jbzen wrote above:
Quote:


I ended up moving the Victrola Credenza and Wicked One from the right and left side walls flanking my chair to a position right behind the listening chair. This created a well balanced sound stage that just transforms the venue to my space. The music now cradles my being...outstanding!

Hi Mrchipster,
Sorry to hear of the hack on your C9. You could always undo the bypassed internal fuse with a bit of soldering and installing a 1/8 amp fuse. I think that the e external fuse holder was used in later models to add protection for the accessory outlet. My C9 does not have an external fuse holder. According to the service manual schematic the accessory outlet just parallels from the mains plug without fuse protection.
Without fuse protection a power surge could fry the C9 step-down transformer as well as some failure with the diodes downstream of the tranny. The odds are slim that will happen but possible without quick action of fuse protection.
HTH

Just some FYI:






If your model is USA only, then the 1.8k line resistor is not installed. That is for CSA only models.

As you will see in the following images, my C9 built in the second half of 1986 has the fuse built onto the PCB itself internally.

Not sure if this model ever had the fuse factory installed on the outside. This may have been a DIY add-on. ??? Obviously, there were revisions to this model during the production period it was being manufactured.

This unit was not equipped with a power switch. The unit must be plugged into a protective switch outlet for control. I have mine plugged into the surge protector.  

This image shows the upgrade version that I will be using when I build my new C9 clone. As you see, there is a IEC power switch with a built in external fuse. Makes much more sense to do it this way. I will be upgrading to a much higher quality toroidal transformer as well. The new unit will use better quality diodes and far better caps in the power supply.  All components will be audiophile grade close tolerance parts where necessary.






I highly recommend upgrading your unit with this IEC fused power switch as shown. As discussed previously, the RCA jacks definitely need upgrading to a higher quality version. These are the two areas that I don't like about the factory version. It all comes down to corporate decisions to cut production costs.  Certainly this was a very bad choice, who ever approved that decision.








We can do better than this!

Hey Mrchipster!
Good to hear you are enjoying your C-9. It is a special add on. I like your reference of Zrock quality of value in a system 👌.
You must have spent a good bit of time placing your speakers for best sound in your room prior to the C-9. I on the other hand used the C-9 to find the best placement of speakers in my room. I purposely pulled the C-9 out and have listened to find that Steve's gear is leaning more to the forth dimension then ever! The C-9 is well worth the $100 or so investment. It adds so much at a very low cost compared to what is out there.
I think your unit is a CSA model. It has a different tranny and it looks like there is a 2 watt resistor lurking in the back of the transformer partially hidden by it. My PS caps are colored different then yours and RPSs two are blue and two grey. It might have been someone doing an upgrade or needed replacement. I have not lifted the board to find out yet.
Here is a link to the patent for the C-9 issued to Carter.
https://patents.google.com/patent/US4218585
It is a hard read...maybe someday I will!

Yea! Moving heavy spiked awkward speakers a bit here and there is a real pain in the ass! I gave up years ago until the C-9 and RPS came along. The card that tumbled my efforts was when I painstaking set the foundations with spikes and speakers in position using a laser and level only to find that one speaker ended up higher then the other. I had to start over to get both the same height. My floor is concrete. The house was built by a Westinghouse manager that used a lot of Westinghouse building maintenance materials and he must have got some of his subordinates to do some freelancing on his build. The concrete has a 3/4" difference in height where my speakers sat. I've learned and made sure the foundations were on the same plane before the new setting.

I may have time today to take some pictures of my C9 internals. It looks a lot like RPSs except for the 2 blue caps. I shied away from those external fuse offerings when searching on ebay. RPS's back story on Carter gave me pause to find one similar to his. Turns out that those units with the fuse are more or less adhering to Canadian electrical code and being yours is an early version my worries about those were unwarranted.

The noise that I was hearing on mine could have been the interconnects. I was using my unshielded silver reel to reel interconnects that was handy. Those reached but ran parallel to some power and the C9 was setting(still is but not in the loop now) on top of the CSP2 and ZP3 power trannies. Not an ideal location! I need to make more of Decware interccont clones as soon as time permits.

Speaking of time...I'm running behind a bit. I've got a lot done but the Chariot is not where it should be. Room treatment is down for needed adjustments. It all needs to be back in place before the 29th when our family celebrates Christmas this year. That is where my oldest and husband sleep!

I learned a long time ago that if it ain't broke leave it be. Seems you are totally enjoying the C9. I would keep doing that for now. Let us see what RPS comes up with. It would not be hard using that external fuse holder to add protection in your C9. Some solder and a 1/8 amp fuse would do it.

RPS have you managed to do the point to point of the C-9? For some reason my vision comes up with an uncovered golf ball

Best to both of you guys.
 

I came across one picture that shows a unit with the external fuse holder, but it didn't show the serial number. I assume mine was the 606 unit built sometime in 1981 or 1982. (just a guess)
My unit has TI opamp chips and the others (newer rev's) I've seen have something else (Xilinx maybe?)


Yes, the unit that you purchased is indeed a very early production model. The first units had the mount rack notches. The later models did not. I will post a video pic of Bob Carver doing a product presentation which includes the new C9 unit in 1982. He is holding that new unit which looks exactly like the one you have. Bob has stated in recent years that the C9 sonic holograph generator was the best selling device that he ever produced. That equates to a huge amount of sales.

As for the opamps in the early unit. I see that the first production units used Texas Instrument chips that were manufactured in Malaysia. That surprises me that we were already having these devices produced overseas during that period. When you examine the chips used in latter years such as mine, the chips are EXAR Corporation XR4136CP quad opamps.

The new Texas Instrument opamps that I just purchased from Mouser Electronics are current production RC4136N quad opamps.

As for the inferior soldering job inside of your unit, I really doubt that Bob would have allowed such shoddy work in production models. I am sure that your unit has been hacked and who ever did that work was lousy at soldering. I am thinking that some mods were done and perhaps a few caps replaced. I have owned many amplifiers and other gear from Carver during the late eighties, and I never witnessed anything that shoddy inside of those components. Back in 1986-87, I purchased the Carver C4000t pre-amplifier with the sonic holograph generator integrated within. I also had a pair of Carver M1.0t amps bridged as mono blocks, and a single M1.5t amp as an extra. I had the Carver CD player with the time lens. I had the new Carver Amazing loudspeakers to complete the system. So I had many years of extensive experience using these components. Not once did I ever incur a problem with this system. This was the best bang for the buck that one could buy during those years. For the price, nothing could even come close to matching the performance of Carver products.

These amp designs were upgrades as a result of the great Bob Carver NULL challenge in a blind test to match any amp competitor at the time to be indistinguishable from Bob's modified design in a listening evaluation by the experts. We are talking about top of the line ultra expensive esoteric amps of the day such as McIntosh, Krell, Mark Levinson, etc. I don't recall the exact model that went head to head during this test, but it was one of the most prestigious tube amps of the day, one that was way out of reach for the average person to own.

Bob was given 24 hours to accomplish this task. He was given the competitor amp to use in the lab for the null test. He did accomplish the challenge and actually won the bet. (the challenge was to match perfectly the transfer function of the competitor)

Of course, the expensive tube amp indeed was better built, and actually had superior sound qualities. The bet was that he could not match the amps from a technical perspective (particularly the transfer function), one that the testers could not tell the difference. I doubt that the Carver amp mod made during that challenge was anywhere near the actual quality of that amplifier it competed against, but that challenge is history as he indeed DID match the transfer function of the ultra expensive tube amp, and Bob made a fortune as a result of it.

I ran those high powered M1.0t amps (M stands for magnetic field/ t stands for transfer function) driving the massive Amazing loudspeakers which were massive panel speakers using full length ribbon arrays and four aluminum subwoofers per speaker. I will tell you this, those speakers had extremely immersive imaging with a huge sound-stage. They were power hungry and required a great deal of dynamic headroom to prevent overloading. But with the revised M1.0t mono blocks driving them, they were simply incredible to say the least. No wimpy amps could even begin to drive these massive panel speakers. The mono blocks drove them effortlessly all day long producing some very dynamic levels of music. The only time that I ever clipped these amps short term was during the cannon fire from 1812 overture recorded on the TELARC audiophile label. This CD came with a warning to keep the amp volume control at SAFE levels, as the dynamic range can easily unseat speaker cones from over driving.

Of course, I had to push it and find out just how much volume I could get away with before clipping. When I did hit that level, the clipping was soft and very momentary. I then reduced the level to just below that clipping point. When that cannon fire went off again, this time it sounded real and the dynamics were intense. The cloth covers actually blew forward under intense pressure from the subwoofers. The covers rippled with strong force as I felt the wave of air pressure rush across the room and hit me in the chest. Any items sitting on the shelves were at risk of falling off. The walls would shake violently at that point. So it was obvious as to how much force these speakers were putting out when pushed hard.

I love the interaction of music when a system can actually do that and not sound like crap. Crystal clear, highly defined, and with great authority.  As a result of magnetic field coil transformer technology, these amps always remained cool to the touch. They were very efficient and produced huge levels of power. You will have to hear Bob's explanation of how that technology works, and why he decided to use it for his amps. The results are obvious as to why this proved successful for him. Where else were you going to get amps of this caliber at a ridiculous price that was easily affordable, but way ahead of anything else at three times that price. That became possible due to the reduced cost to manufacture amps using his patented Magnetic Field Coil Technology, compared to how more expensive amplifiers were built. They were an extraordinary concept at the time and proved to be very successful and in demand for the average consumer.

In a nutshell, the basis of the output transformer developed for the magnetic field coil technology worked by designating one half of the sine wave to be driven by an isolated power source in A/B topology, while the other half was driven separately by another power source in similar manner. The efficiency of these transformers came about by special windings that allowed for this type of operation, yet able to run as if the amp was a Class A amp, and do so WITHOUT NOTCH DISTORTION!

The resulting output power acts as if it were pure class A power, as standard class A amplifiers operate. The two separate power sources driving this A/B topology actually drives the separate positive and negative sine waves in class A operation independently, but with the efficiency of class A/B, and do so without notch distortion. This is the basis of the tracking down converter, along with special windings in the output transformer which makes this concept possible. A switching scheme using a TRIAC is used to control this topology.


The magnetic field coil design only utilizes the power supply on a "as needed basis" rather than running full spec all of the time. Excess energy is stored within the special transformer windings (the magnetic field coil) and available for demand when the amp requires it. This eliminates the need for massive capacitors to store the energy needed to drive the amp at demanding loads such is the norm with most large bulky amplifiers which operate so hot that you can burn yourself.


I would not compare the musical attributes of these magnetic field coil amps to something such as the Tori zen amplifier designs of today, but back in the eighties, these amps were very special and a pleasure to own. After all, for the price difference, one cannot afford to make that comparison in a reasonable manner which would be justified with something that cost ten times more.

Just like you can't compare muscle cars from that era to what we have today. The difference in technology is so extreme, that any idea of a challenge would be pointless, and quite laughable to say the least. A dodge charger R/T equipped with a 426 Hemi was king of the day back in the 70's. Today, a supercharged hemi dodge challenger would leave it in the dust before it even got off the line. Sort of like comparing a world war II Mustang with a F22 Raptor today.


Anyway, I got off track there and wrote a short story. I just wanted to note that quality control standards in production would have never allowed something of subpar quality to leave the factory like that. The product wouldn't last long if it did. I am glad that my unit was stock, and untouched after all these years. I am sure it is due for a cap change, and perhaps an opamp change, but so far, the sound quality does not suggest that, so for now, it is fine.


Oh, BTW: Bob stated in an interview that the original cost of the C9 was only $275.00 back in 1982! Even back then, this device was a steal for the price. I have yet to see any competitor produce a device that can do precisely what this unit does, so that makes it far more valuable than mere cost would suggest. My system would not be complete without it.


So once again, I left my time short with what I really wanted to say tonight, but I will be back to continue this soon.

mrchipster, in reply:


I notice that you're considering using the TI OPamps. My unit has TI but all the other pictures of this unit I see have some Xp designated OPamps (not sure what that is). Anyway, if I have the unit 'refreshed' I think they may move to the newer Xp types. I think maybe yours and JB's might have the newer Xp types. Would you recommend staying with the TI (maybe not replacing them at all or replace them back with new TI versions) or allowing the newer OPamp types to be used? If all goes well for a while I may choose to get it refreshed (back into spec) which will also get the fuse re-integrated and would do the RCA jacks update/upgrade as well. I think it would be money well spent, what do you guys think?


This is certainly a warranted effort which really should be done with a unit made back in 1982. I am sure that someone already played around inside of that unit from the looks of it. Since you find the sound acceptable, then perhaps that owner did it right without changing anything in a negative manner.

Personally (this is exactly why I am building a new unit from scratch using tighter tolerances and higher grade components), as a minimum, I would upgrade the power supply caps, diodes, and especially, that transformer. While you are at it, install a fused power switch with an IEC power cord, and upgrade those RCA jacks. As cheap as the opamps are, and being readily available online, it would be foolish not to upgrade the five opamps with newer versions, as they do tend to drift out of spec over time.  I have to think that the newer versions are better quality than those offered back in 1982.

Here are the part numbers and cost for the parts I recommend changing:

From Mouser Electronics online,

# 595-RC4136N........MFR# RC4136N...Texas Instruments Quad opamps.  *(need 5 total) @ 0.96 cents each!

#575-113314......MFR# 110-13-314-41-001000....IC component sockets, 14P GOLD PIN *(need 5 total) @ $2.25 each.

NOTE: the following capacitors are good quality and a perfect replacement for this circuit. HOWEVER, since your caps seem to have differant values than mine, perhaps you need to stick with the values you have in your unit. There most likely was a circuit revision over the years from 1982 to 1986 when mine was manufactured. Just make sure that you order the correct values.

In MY unit, the values would be:

#647-UEP1C220MDD......MFR#UEP1C220MDD..aluminum electrolytic capacitor, radial leaded, 16 v 22uf 20%..*(need 2 total) @ 0.30 cents each.

#647-UKT1E102MPD...MFR#UKT1E102MPD...aluminum electrolytic capacitor, radial leaded, 25v 1000uf AEC-Q200..*(need 2 total) @ $1.05 each.

#647-UKW1H2R2MDD...MFR#UKW1H2R2MDD..aluminum electrolytic capacitor, radial leaded, 50v 2.2uf  20%..*(need 1 total) @ 0.15 cents each.

If you want to change the JFET's, (optional): #810-2N5458...MFR#2N5458 PBFREE....JFET N-ChJFET...25Vds 25Vdg 25Vgs
          ................................................................................
..............................10mA 310mW.............*(need 2 each total) @ $1.22 each.


I recommend at the very least changing out those caps as a minimum. You will have to research the actual values needed for your model. You know what substitutes are allowable. The caps shown above are NICHICON. Hard to beat that quality.

I will be using all Vishay 1% and 2% tolerance metal film resistors in my build. I am considering stepping up to tighter tolerances on my capacitors over the stock values. They will cost more, but very worth it. I have heard that the Sanyo OS-CON caps have the most desirable sound signatures over other electrolytic types. They are great for bypassing and have proven highly desirable in DAC circuits. So that is something to consider.

I already have the NICHICON capacitors that I ordered. So this upgrade is optional with the OS-CON's.

I am upgrading all other caps to VISHAY 5% or less film types, with the exception of some ceramic disc caps, also VISHAY. I think there were a few WIMA types also.

As for the signal switching diodes, there are two types needed.

#494-1N4148-1....MFR#1N4148-1..........small signal switching diodes 75v.....*(need 2 each) @ 0.74 cents each.

The other diodes can be found on E-BAY. I did not find them on Mouser.

**DIODE IN4004....400V.......*(need 5 total)....around $5.00/ free shipping.

If you decide to populate the entire board with fresh components, then I can provide you with the complete list of parts and part numbers from Mouser. The only thing needed outside of those parts are the transformer, IEC power switch, IEC power cord, and RCA plugs which you can find online. The overall cost is very affordable and will be worth it.


Not sure about how you feel concerning DIY and your ability to solder, but if you can do this, then upgrade this unit yourself. If you are not comfortable doing this, then find someone that you can trust to do quality work and NOT overcharge you. Perhaps JB would offer to upgrade yours when he does his own unit. I know he will do a good job, and he will be fair about it. I think you can do it. Just practice your soldering skills on something else until you feel confident to work on the C9. I have a feeling that soldering is already one of your acquired skills from past employment. I could be wrong, but you did work in that environment as a chip designer, am I right?


As for your suggested music selection to try out, I will try to find it online and give it a try when I get time. I am not familiar with that artist but surely will give it a whirl and let you know what I think.

mrchipster, if you care to send me a PM with your shipping address, I will put together a very nice music sampler made from very rare audiophile recordings such as my new LPCD tiles (including Dire Straits, Brother's In Arms, and Pink Floyd, The Wall) which I will transfer onto lossless FLAC discs. This is a gift to you for evaluation purposes, and I will cover mailing cost.

I will select various titles that I know shine with the C9 unit. These titles have an abundance of spatial content that are perfect for evaluating the C9 holography difference.  You will certainly be amazed at what you discover. I have several direct to disc from the master tapes LPCD classical recordings that will absolutely prove just how good your audio system really is. It simply does not get better than this unless you are listening to the actual studio master tape...and not by much!  I would like for you to evaluate these so that you know just how good that C9 really performs.  One thing to note: Classical music usually does not offer much in way of holographic imaging. The C9 only places instruments in proper perspective as engineered by the studio on the original tracks. If a wide spacial aspect was not intended or produced that way, the C9 is not going to change that. For classic rock, and especially atmospheric music such as "new age" (Vangelis, Tangerine Dream, etc.) will definitely be among those that are meant to have wide panning and special effects within the original studio master. What you experience using the Carver C9 holographic generator completely depends on what was actually recorded in the music. It can't produce what is not there. It only "corrects" what IS there.

So if you would like this care package, then let me know. I will be happy to send these to you....FREE! I promise you that it won't disappoint.

I just ask that you post reviews here concerning what you experience. And don't worry about the length of your posts or future reviews, I welcome you to do so. In fact, I encourage it.  This is all part of exposing the need for the C9 in the music world. As more and more people are convinced, the likelihood of resurrection for the C9 becomes closer to reality.

I found your room arrangement process interesting. I am glad that you are doing it right. The results are in your favor.


Oh, and yes, I found that shocking experience with the interconnects rather refreshing. I feel so much better now...and WOW, my hearing actually improved!  As for the madness, there is no cure for that.

Okay, here is the link to that 1982 Carver presentation that goes in depth about his products and the C9 sonic holographic generator. If you look closely, you can see that the unit he is holding is exactly like yours.

Bob shows his goofy sense of humor in this cheesy presentation where his assistant is Miss Hologram.  Looking at these audio geeks reminded me of those years when I was one of them...lol    That was certainly a different era.

The big preamp is the C-4000. The one that came about around 1986 was the C-4000t with the upgrades. That is the model I owned. The very first amp by Bob, the "Carver Cube" was when I became aware of his products when I listened to one with a Nakamichi Dragon and Acoustic Research speakers back in 1985. I could not believe what was coming out of that little cube. It got my attention.

Carver Corporation was not his first gig. He had success with Phase Linear before he created this company. He finally evolved into what he always wanted to build from the start, vacuum tube amplifiers. Up until he retired (he is in his 80's now and still sharp as a whip) his entire focus was on tube amps. Ironically, his last company before shutting it's doors due to the Corona virus impact was called Bob Carver Corporation. This was his final gig after selling Sunfire Corporation.  He certainly cashed in on major profit from that transaction.

So watch this bit of history if you like. I think you might get a kick out his presentation. Gotta love those 70's outfits!










There are a bunch of videos with Bob being interviewed in his latter years, right up to his last show earlier this year. Just search for his name and many come up on YouTube.  I particularly like the one with his presentation of the ALS line array speakers which are built to produce a similar effect as the C9, but with acoustic technology built into the speaker designs themselves.

He told the story about the ribbon elements that he designed for these speakers. He went to HiVi in China to have them built. They wanted $100,000 just to gear up for production. He offered to give them exclusive rights to own and sell these drivers after Bob had exclusive rights for the first three years. After that, They could sell them to anyone they wish. These ended up being a major seller at Parts Express. Yes, Bob designed those planar drivers. They are the very same ones in the ALS line arrays.

I just happen to have a box full of these drivers brand new. Really has me thinking about the possibilities for using them in a design like this.