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Ha! Actually the Stoke DAC was completed January of 2003, so 21 years of service. Seems my whole journey began the turn of the century leaving me believing that every part is 25 years of age! I remember meeting up with Sheldon Stokes along with Dave Elledge in Albuquerque on my first cross country trip back in 2004. Those two were definitely deep into the engineering aspect of audio. Way above my pay grade at the time.

Sheldon's DAC has kept up with all the upgrades in the Charoit over the 21 years. It still beats the ZDAK(which seems a bit cold in comparison). It has become noisy lately. After adding the Subway and Mainstream it became apparent that the Stoke needed some work. The plan is to line the Corian case with copper tape and replace the caps, let it break in, and see how it goes from there.

By Saturday there should be enough parts here to finish 6 of the projects on the shelfs.


But its going to be in the 50s tomorrow so I may start in the wood shop with building a couple diffusers. Choices, choices keep me on my toes!

I am gearing up to start doing some preliminary evaluations. There have been a few major changes within the system. The room acoustics are unchanged at this time. These changes are mostly within the audio components.

I want the set-up to be as good as I can get it for now before I make any future upgrades or introduce any more components within the signal chain.

I believe within the next two months, I should be including the new Zrock3 within these evaluations. Other future upgrades include a highly modified project DAC that allows both OPAMP output stage listening (with chip rolling), or an optional tube output stage using a single 6922 tube per channel.

Later this year, I intend to build a new set of speakers based upon the very old Jensen ultra-flex designs for the Tang Band W8-1808 full range drivers that I am now using in my custom Q-force designs. These are Tapered Quarter Wave designs with rear bass enhancement.

The main speakers are going to be modified to my specifications as a major improvement in three dimensional sound staging. I have a custom design in mind that I want to implement within this old design. It will be much more complex than the original. Simply using the original platform as a starting point.

The mains are separate from the dual bass Jensen ultra-flex enclosures which are driven by 15 inch Eminence subs. The subs can be positioned anywhere within the room to find the best bass response. The mains must be positioned towards the front center, but away from the wall a bit. This allows custom tailoring of the frequencies much like using an EQ, only with much better results and sound quality.

I just upgraded these speakers yesterday with the W8-1808 drivers, removing the crossover networks to run these wide open in full range mode. The best crossover network is NO network. Can't get more transparent than that. This way, the restrictions or changes created by capacitors and inductors are completely removed from the evaluation so that they don't get into the way.

The W8-1808 drivers are already broken in with a great deal of burn time. I have had these for years and they have been sitting idle in another set of speakers. It is time to put them to the test.

I listened to this upgrade mod last night. The results were very favorable and quite a bit different than before. Not that anything is better or worse, but that the sonic signature is definitely two separate points between the two. The W8-1808 drivers are very sensitive. I use even less amplifier power than before and the dynamic range is simply stunning. (on a scale of 1 to 10 on the volume dial, this would be about 2.5)

 I took out the tame cats, and replaced them with wild beasts! I'm sure that running them free range without crossovers plays a big part of that change. Absolutely zero components to color or mask the sound. With the new copper foil speaker cables, the definition and clarity is like breaking the damn window which was thought to be clean. There is absolute transparency now. The crisp attack and decay of cymbals are so realistic, the extension goes way beyond and clearer than before. I thought I had lost much of my hearing and didn't question that because of my age.

I just let reason assume that I would never hear this level of high frequency detail again. To my surprise which I am so grateful for, this is not the case. The damn crossover networks were masking much of this delicate detail. This is exactly why open baffle speakers using full range drivers without crossovers are favored so much by audiophiles. They don't stand in the way of musical truth.

That is why I stated that expensive capacitors are not the first thing to spend huge amounts of money on. Concentrate on the quality of drivers first, then make sure you build a platform around them to extract every bit of detail and quality possible.  Full range drivers don't need crossovers anyway, so that should not even be part of the equation. The only thing I would ever consider is an impedance stabilization circuit, and that is about it. It doesn't take a grand worth of parts to make that happen without masking or tainting the sound quality.

So far, I have not heard any reason to do so within this new set of drivers. These are sharper and much more revealing, so the upper end naturally sounds louder than before. Of course, there is a rise in response above 13 kHz compared to what I had before. Previously, the speakers were almost perfectly flat in response from 120 Hz up way past 20kHz. And that was at a 92 dB center point. Fluctuations remained stable within 3 db across the spectrum within that range (not accounting for the room's frequency response). So it stands to reason why the high frequency detail is much more open and revealing. The copper foil cables had a lot to do with this improved sound quality.

And as for sound stage and holography, absolutely it is immediately apparent from the second the music starts that this is a substantial improvement as well. I am really finding out just how pure and clean the ToriMK3 really is. At this point, the sound quality of this amp (well burned in), with the Mullard reissue El34's and Electro-Harmonix tubes otherwise, proves to be the ultimate arrangement.

Everything sounds so well balanced and natural. I just can't find fault with it so far. I am going up for another listening session tonight. I have much more music to evaluate to see where these speakers are going for me. So far, I am very pleased. Actually, I am a bit shocked at what is being revealed.

Do yourself a favor and get a set of these Mullard reissues from New Sensor. They bought the rights to the Mullard tubes, and have them made in Russia. If you don't like them in the Tori amps, then your problem is not with the power tubes! These are the most liquid and dynamic based  across the frequency spectrum that I have heard to date. And they are reasonably priced. This is the most hours I have ever extracted out of a set of power tubes yet, and they have yet to sound anything less than spectacular with my amp. Yes, they have been cryo'd whether you think that makes a difference or not.

I will get back to this later. I will disclose everything in the signal path when each evaluation is completed.

This will be coming soon.

Yes, I have to agree with you concerning the overall perception of music as we age. The majority of what we need to hear is primarily within the midrange anyway, as that is the most critical area. As long as we can hear well in that range, then everything still remains acceptably balanced. I do miss the way my hearing was when I was in my twenties.  I think I had super hearing back then...just joking.  Compared to today, that may be true.

I used to say that I could hear mouse flatulence in the other room when it was quiet enough. But seriously, my hearing was way better than it is now. I know from many years of critical music listening, both from high end audio, and that of many live events, just exactly what I am missing now.  These factors may seem minimal above 16 kHz, but I know from memory what is no longer apparent to me.  That delicate presence of "air" which happens at the high end of the scale is one thing that I recognize as missing, or at least nowhere as clear as it once was.


Maybe if I wire one of those capacitors that cost the equivalent of "gold per weight" between my ears, perhaps I can hear that again?





You see where the presence of "air" falls within the frequency range on this chart. If you can still hear in that range above 16 kHz, and you are over 50 years of age, then you are really fortunate!






Understanding the Audiogram

   X and Y Axes: The audio-gram has two main axes. The horizontal axis (x-axis) represents frequency or pitch, measured in hertz (Hz). It typically ranges from low pitches (250 Hz) on the left to high pitches (8000 Hz) on the right. The vertical axis (y-axis) represents intensity or loudness, measured in decibels (dB), with the softest sounds at the top and the loudest at the bottom.

   Thresholds: During a hearing test, the audiologist finds the quietest sound you can hear at each frequency, known as your threshold. These thresholds are marked on the audio-gram. A series of these marks across different frequencies creates a profile or "line" that visually represents your hearing ability.

   Interpreting Results: Normal hearing thresholds are typically between -10 dB and 15 dB. If your thresholds are within this range across all frequencies, your hearing is considered normal. Thresholds that fall below this range (higher dB numbers) indicate hearing loss. The further down the chart the thresholds are, the greater the degree of hearing loss.


The way I see it, for the most part, unless there is critical damage within the inner ear, music is still very much interpreted on an enjoyable level. If your balance is optimal from 10kHz down, you are still perceiving the majority of what lies within the soundtrack. When it comes to Classical music, this is where the restriction is most apparent due to the extreme dynamic range, and the delicate nuances of the upper frequencies which play a major part of that music. The "air" factor is most perceived here.

As for Classic Rock, or Metal, then you are not likely to be missing enough to make a questionable difference. That would be so minimal that it isn't a problem at all. Most music other than Classical will remain lower in the registers for the majority of the recordings out there. Once subjected to heavy compression/limiting, it absolutely does not matter anymore. The studio already ruined the recording in the final process.


Anyway, not going to go any further with the hearing aspect of music. Just making it clear so that we can rule out the BS factor.

I realize that I am inflicted with this loss, so I make that clear when I give my perspective upon what I hear in the music. The fact is, there is detail within the upper registers that I know are there, and damn, I wish I could hear them, but I doubt that I can.  I am very accustomed to what much of this music sounds like from my early years, so this can't be questioned as a factor.


The following images are what certainly led to my current situation. After decades of exposure to aviation, even though I always wore OSHA approved hearing protection, I endured intense pain within my ears when subjected to intense military afterburner decibels which can easily destroy hearing very quickly if not protected. The high frequency pitch of the airflow as it passed through the Vari-Ramps (variable intakes) of the F-15 was one of the things I had long term exposure to at close range. The intensity of that noise is very painful to the ear, even with earplugs AND headsets in place.

I remember back in 1982 during war simulation exercises at Nellis AFB, NV, engulfed by a sea of fighter aircraft swarming all around, constantly taking off and landing, the culmination of all jet noise became unbearable after 12 hours of exposure. Between the noise and the smell of burnt jet fuel, I would require Tylenol that night just to relieve the massive headache from that exposure. My ears were very sensitive to loud noise back then. I am sure that this did not help matters. The good news for me is that I had my hearing checked professionally in a controlled audio-gram booth every six months the entire time I spent in aviation.  Up until my mid thirties, I still had exceptional hearing intact and above average for someone my age. When you approach nearly three decades of this exposure, the outcome is going to be negative.

Here are two examples of what I worked closely with during the eighties. The B1B bomber, and the F-15C and D model fighter. These produced the loudest, and most intense decibel levels that one would ever want to be around long term. Very painful to the ears even with double hearing protection. The low frequency impact was equally as intense as it ripped through your body. Kind of like when Army Howitzers are being fired at close range. But you know what?...I LOVED THE HELL OUT OF IT! Those were proud days for me.

To all of you brave American military personnel who served the USA with pride, I stand with you for your great courage and selfless contribution dedicated to a FREE America!  Freedom is NOT free! The American way of life came at an extreme cost. We almost lost it.

I am proud to have served the many years which I contributed to make our world a better place. I am grateful that I did not become one of the many casualties of war. I know that the alternative is loss of limbs, loss of mental health, and ultimately, loss of life. So you see that considering how bad things could have been for me, for which others are not so lucky, I never forget, and I always honor those who gave the ultimate sacrifice. I salute you with the absolute respect that you deserve. Keep our flag flying proudly!











But thankfully, I managed to get through all of that with my hearing intact, for the most part anyway.







Oh, and of course, my exposure to many, many rock concerts might have had some effect upon hearing loss, just maybe.  That is the thing that is so nice about listening to a symphony orchestra, no ringing in the ears afterward.

 I can't add much to what you have already said except to agree with the method of measurement for distance of each driver to the ear. Congrats. You wouldn't believe how many people think that they can eyeball this part. Nope.
The 1808 was the driver used for the ZOB cabinet design. Steve said that he was so surprised at how little that it needed modification compared to the other drivers that he tried using. They have since gone way up in price and are even discontinued if I am correct. Good job with this mission. Seems to me that you got all the parts right, so implementing all this in a listening environment (if you haven't already) is the last step.

I'm not sure how you damped the inside of your cabinets. Reflections from the back cabinet wall, slanted or not, will fire right thru the back of those paper thin cones. Not an issue with open baffles setting out from the listening space's back wall.

Something to consider.

I enjoyed your service stories. Will have to tell more the next time we get together.

I can't leave anything alone. Certainly not a speaker cabinet or design. I just got to know 'what if' results. In this case, I moved the black short horn to and fro, attempting to get more bass into the slot feeding the bottom cabinet/resonator.

Some more detail for recent upgrades that will be used in upcoming music reviews as revealed within my fully dedicated highly advanced acoustical setting. There will be a progression of changes within the system as these evaluations unfold.

It all starts with the latest revision to my own custom speaker design built to the highest standard. These are an advanced version of the Tapered Quarter Wave design method. With rear passive bass extension, and thick stable construction using Baltic Birch, these speakers perform at a level which simply can not be surpassed for a speaker this size.  These are proportionally raked back at 5 degrees, with matching cradles which support as bass reinforcement chambers for deep extension.

I am currently using them directly on the floor without the cradles. Super efficient and extremely dynamic, with a strong focus upon imaging and clarity. The Q-force design is as revealing and transparent as one could ever expect a speaker to be. These are far more complex than what meets the eye. It's what you don't see that makes the difference. The sound quality proves that.

Listening confirms the intended promise to the highest regard. I spent a small fortune and a great deal of time perfecting this design. I am now taking this level even higher with the latest driver upgrade. With very little amplification, this design will quickly go beyond the sonic limits for which most listeners never exceed.

These produce very serious decibels which go beyond safe listening. They never over taxi the amp, with most of the power idling in reserve. Only the most demanding transient peaks will nudge the amp up for more power short term. Whether your passion is Classical music, or the hard hitting force of Metal, these speakers easily portray vastly different music styles with unfaltering presence one expects to hear.

If you desire the ultimate speaker for mini-watt SET amps, this design is a perfect match. No longer will you desire more bass extension, or have to feel "limited" by a substandard sonic presence. 2 or 3 watts per channel will drive these very efficiently in a very satisfying manner. Nothing like what the Torii amps will, but you better have a large room if you need power on that level.  Anything above one quarter of the Torii amp range is simply too loud, leading to dangerous levels which must be kept within reason.  It sounds great, but the decibel level is intense! (that is if you use an uncompressed high quality master recording with full range intact )

That intense relationship with music in the physical realm is what makes music so exciting within it's forceful presence, at least for me anyway. Reminds me of being close range to the action at an NHRA event when top fuel dragsters are in this vicinity.  Well, maybe not quite that intense, but you get the drift.  It is where the excitement level takes things up a whole new level. The sound quality of music is one thing, but I have to FEEL it's presence to be one with it.



Something this intense is enough to give an old man a woody!

I love the smell of burning nitromethane in the morning.







*lower quality recordings require much more power to produce the same sonic equivalent, or at least "attempt" to approach that level.  Heavy compression/limiting destroys the recording. There isn't much one can do to correct for that other than try a Z-box in the signal path.


If you love it loud with gut penetrating bass, then you will get your wish. With the new full range drivers, I am well satisfied with the decibel factor and dynamics of my system set at no more than 3 or less on the volume dial. (scale of 1 to 10). The feel of the music is physically impactful at this level, and the sound pressure becomes intense but still with a firm grip on your senses that feels just right. For me, this brings the music at it's peak of immersive drive without over doing it. There is no need for a more powerful amplifier. All it takes are properly engineered speakers PLUS a high quality class A amplifier. Simply no need to go beyond that.  

*This of course results by the addition of an external bass enhancement system driven directly from the ToriiMk3 outputs as an extension of the mains.

Instead of placing the subwoofer drivers in the same enclosure with the mains (which leads to substandard bass performance due to room placement), they are instead placed in the part of the room where room modes do not affect them in the least way as possible. They are still driven in stereo mode independently as drivers, but work together in a push-pull configuration for optimal results. If the woofers are efficient and with reasonable speed, they do well to enhance the mains. Without strong bass response, I will just turn the system off and walk away. To me, music sucks without deep low frequency information. That is an important part of the music, right?

Full range driver speakers do not hit hard enough, or low enough to meet my satisfaction (when used on their own). They do everything else very well, but bass frequencies are not something I am willing to overlook.

Think of how much extension one fails to hear without the capability to recreate something like pipe organs. If I don't feel those lower registers, then I am not getting the whole picture. It may not be on the same level as that same organ playing in the gigantic cathedral from where it was recorded, but at least it becomes a more believable representation which can be enjoyed very favorably.

The ToriMk3 is a low frequency beast as it drives these speakers. When switching impedance between an 8 ohm load and a 4 ohm load, the level of low frequency dominance varies to a wide margin. One position creates a low shelf mode which extends deeper, with more impact upon lower frequencies. The other position virtually creates a heightened upper bass range which is more subdued by comparison.

The bass response is at a higher "shelf" with a leaner response within the bass region at 8 ohms. It is very noticeable to the point you would think something happened to the speaker woofers (like turning the bass tone dial all the way down). This results in a more subdued presentation of the bass without the brute force at lower volume. For high quality recordings that produce strong levels of low frequency content, the 8 ohm position is more ideal for well controlled bass output. When you need more bass, or just like a strong bass attack with physical impact, then the 4 ohm setting will give you that. I run this amp in high bias mode for full robust presentation.

I have auxiliary low frequency enhancement provided by an external enclosure using twin 12 inch drivers in a push pull fashion (wired in stereo). The auxiliary low frequency enclosure is driven directly from the ToriiMk3 terminals along with the mains. For the best control and balance between this unit and the main speakers, the best balance seems to be at the higher impedance setting, driving them as one. The bass extension is deep and fast paced when set to this position.

If you want bass so powerful that you want to see particles falling from the ceiling, then use the 4 ohm position. The bass response is absolutely tactile and deep. Of course, the 4 ohm load is driving the amplifier harder, so this will influence the sonic character switching from 8 to 4 ohms. The difference is quite substantial. I place the auxiliary bass enhancement to the rear of my position for better room response where it is most effective in the room. Always consider the pathway of nodes and anti-nodes within the room. Where you place a woofer makes all the difference in output and definition.

My future speaker design will surpass the current speaker design in a different approach, as I am taking that design to extreme levels of engineering. A major part of this design is in how the rear wave is directed and controlled within the room in direct relation to the focused front firing driver in relation to your ears. With tuning wave-guides (adjustable), and a touch of phase inversion along with a few milliseconds of induced delay at corresponding angles of projection, the goal is to create a morphed assimilation between speaker and acoustic environment, evolving into a complete submersion of high dimensional holography induced space.


That synergistic marriage is where I set out to create the ultimate combination driven by the ToriMK3, sonic holography, and a highly modified digital front end.

With a well balanced premium acoustic environment in place, it is time to see just how deep I can actually get within the music.  It is time to begin exploring my creations as far as possible within a reasonable and sensible manner. The absolute focus is upon extracting every bit of precision out of the holography principle.

Without that as the main focus of my room and system, all else is meaningless to me.

For now, this is the beginning of that quest. It all starts here at this level. The journey resumes.







The tubes used for the upcoming evaluations will remain the same. No tube rolling as I have determined the current configuration as optimal for my system. I find it very well balanced and simply without anything to desire.

The following is my current system configuration. This will be the beginning stage using what you see here.



















Next, I will go into detail with lot's of high res images showing the internal layout of my current ZERO (modified 09 version) DAC. This DAC revolves around the highly respected Burr Brown OPA627 twin OPAMPS in the output stage. These are among the best ever produced for high end audio. Piggy back them in parallel fashion, and that quality factor goes up exponentially. Think CPU cooling when doing this. The heat factor becomes a problem.





To be continued.