So, yes, I was so depressed and saddened that my first audiophile tube amp didn't work with my favorite speakers, that I came close to selling it on eBay. I auditioned many of the amps at DecFest last October and based on many factors, I decided the Mk IV was for me, so I knew what this amp was capable of, but I couldn't even get it to sound as good as my old integrated, solid-state amp and basically, it sounded so bad, it was virtually unlistenable. Thus, my quest for seeking Zen began...
Before going forward, the gear:
AmplificationPower: Torii Mk IV with standard beeswax caps, stepped attenuator, and Tung Sol KT66's
Phono Stage: Sutherland 20/20 (separate power supplies feeding dual mono blocks of capacitors for pure DC)
Vinyl SourceThorens 150 custom built by Dave Archambault of Vinyl Nirvana
-SME M2-9 Tonearm
-Dynavector 17D3 Karat MC cartridge
-Origin Live DC200 motor (their top motor picked for it's quietness and less vibration)
-Orign Live Upgrade Transformer (lowered impedance enabling higher instantaneous current to be delivered)
-Origin Live Ultra Motor Controller (faster functioning circuit, stricter regulation, and lower noise)
Turntable feeds into Sutherland phono stage
Phono stage feeds into Torii channel A
CD/Digital Media FileDecware Zen CD/Network Player ZCD240
CD/Media player feeds directly into Torii channel B
SpeakersKlipsch KG4's 1987 (sealed acoustic suspension, rated at 38-20k Hz, 94dB)
-dual 8" woofers
-exponential horn tweeter
-12" passive radiator (rear facing)
-phenolic horn drivers replaced with Bob Crites' titanium drivers
-crossover networks replaced with Bob Crites' hand-built networks
Unlistenable? Yes. The problem: upper midrange glare (referred to as UMG going forward). This UMG was so pronounced that when it hit certain frequencies, you had to jump off the couch and turn it down or off, or play another recording due to the pain to your eardrums. Also, there was virtually no bass or warmth. Instead of the silky smooth highs and authoritative bass that I was use to, I now had the opposite.
I called Steve and he thought it sounded like a bad tube in either the ZP3 phono stage or the ZStage pre-amp (at the time, I owned both those pieces as well as the ZMC moving coil transformer). I tried swapping tubes around that Steve quickly sent me to try out, but to no avail. So, I packed up the phono chain and shipped it back to have an analysis on all the pieces, but they checked out fine as I expected. However, while the ZP3 chain was being re-inspected, I purchased a Sutherland 20/20 dual mono phono stage and things got a "little" bit better regarding the UMG - I attribute this to the Sutherland phono stage having both individual gain settings and load impedance settings that could be more accurately dialed into the moving coil cartridge I was using which has some unusual requirements.
Most of the UMG was still there and the speakers still sounded anemic - bass was only present on certain frequencies. I looked at the "gauge-o-meter" of different tube characteristics on the Torii Mk IV webpage and decided that I would try a set of 6L6's as they were listed as having the wettest sound and loosest bass. So, I purchased a matched quad of JJ 6L6's from the Tube Depot. Upon the initial listen, I was hopeful - the bass had returned and the top end sparkled, opened up, breathed, and the sound stage expanded. However, when I played my songs to test UMG, it was still there! Perhaps a tad not as intense, but it still hurt your ears and made you cringe every time those certain frequencies came about in the song.
I read quite a few informative and knowledgable posts in the Decware Forums by a well respected forum member named "Will" and figured he'd be the guy to ask about seeing if different tubes, other than output, could address my UMG problem. I contacted Will and he has and continues to be very supportive in educating me in all areas of tone improvement. Before he started advising me in tube rolling in the areas of rectifiers, vr's, and input stage, he advised experimenting with speaker placement. Long story short, I was able to vastly improve the Torii's interaction with the Klipsch speakers by incorporating speaker positioning and different tubes. By then, the best sound I could get, and also taming down but not eliminating the UMG, was with the following tube set with my 6L6's:
Zaerix PCC88 (input)
Sovtek Cryoset 5AR4/GZ34 (rectifiers)
Sylvania OB3A [40's] (output vr's)
75C1 [Brit NOS] (input vr's)
This combo of tubes relaxed the "in your face" harshness of the Mk IV, cleared out the density, and reduced the UMG, but it was still there and still fatigued the listening session. However, I must say that this combo of tubes really brought out the best in the Mk IV as far as tonal balance, sound stage, air, and inner detail.
Then earlier this week, I was reading some articles in the Decware Forums that were returned when I searched on "Klipsch" -- there were two postings in particular that pointed me to my Rx for the UMG dys-synergy between the Mk IV and the Klipsch's:
RW82
Re: Torii MK4 - Tube Rolling and Some ObservationsReply #96 - 05/22/15 at 07:21:19
Lord Soth
Re: Torii MK4 - Tube Rolling and Some ObservationsReply #59 - 08/20/14 at 19:08:56
After reading these postings and researching EL34's on the net, including the following review:
EL34-family Tube Comparison by Tim Smith
http://wallofsound.ca/audioreviews/tubes/el34-tube-comparison-with-tubes-supplie...I decided I would have to try a set of EL34's, but which ones to try first? Based on the above article, I was torn between the new production Mullards and Tung Sol's. I couldn't make up my mind so I just went to bed. I had a dream that night that I pulled the EL34's out of my mid-90's Marshall JCM-900 SLX 100 watt head. I woke up the next morning pleased with my prophetic dream. That evening, I pulled out four Sovtek EL34G+ tubes from the Marshall head, put them in the Torii, and played some tracks from albums that exhibited lots of UMG. The result? Drum roll please...
Magic wand! UMG completely eliminated in problematic passages on test tracks. Everything fell into place - complete tonal balance from top to bottom. New inner-detail that had not been there before - was this the Hazen Grid effect that I was experiencing for the first time??? I don't know, but I'm loving it! My Torii as finally opened up the gates to "Zen"!
Some examples of what I was hearing (attenuator at step #15):
Vocal presence: Rhino, 2009 pressing, Joni Mitchell:
Court and Spark, title track: while this track is closely mic'ed, I have never heard her throat resonance and breathiness so pronounced and detailed, and when she sings, "I could complete you", she holds on to the "you" for a long time, it was so holographic, it made my neck hairs rise.
Electric guitar bass test for high and low note articulation: Columbia, 1968, first pressing stereo, Simon & Garfunkel:
Bookends,
Punky's Dilemma: soft acoustic guitar intro with Paul's solo voice, then enters the bass guitar doing a walk. Solid chest feel and clear articulation throughout the song hearing all the runs up and down the neck without any notes getting garbled. (I know what you're thinking, but you have to remember that the loose bass tendency of EL34's gets normalized by the tight, almost dry bass of the Klipsch's sealed acoustic suspension.)
Fore/Aft sound stage test: Decca, 1969, first [US] pressing stereo , The Who:
Tommy,
Amazing Journey/Sparks: Keith Moon's drums appear about five feet off the ground and most importantly, about 10 - 15 feet behind the speakers/voices. [Note: this sort of depth does not exist in the later MCA pressings, only the original Track (UK) & Decca (US).]
This post is already way too long, so I'll stop here, but you get the idea. I demoed many tracks late into the night with my new found "Zen" and they all passed the tests that I was throwing at it, and more importantly, without any UMG! I finally had the "Decware Zen" experience I had at DecFest last October for the first time with my Torii. It has been a long, frustrating, and at times, depressing journey. But now that the UMG has been removed by the EL34's and they have the correct synergy with my Klipsch's, I can enjoy tube rolling now as an exercise to "better" or "change" my listening experience rather than trying to resolve a problem. This is huge.
I was so excited about this, I called Steve the next day to personally tell him that the mystery of the UMG had finally been resolved. Steve also pointed out that a better quality EL34 may or may not necessarily sound better. That was a good reminder because of the complexity of all the elements that go into making good synergy amongst tubes affecting other tubes when just one thing changes. In my case, it's an even more sensitive issue as speakers with horns react very differently to an amp of this caliber. Steve, also pointed out it was a good thing that I first experimented with the cheap Russian EL34's out of my guitar amp because if I had purchased a higher quality set and they didn't alleviate the UMG problem, chances are I would have never tried a cheaper set -- and he's right
I have posted a link to this post in the Torii Mk IV Support Forums under the title: "How to Remedy Upper Midrange Glare Using Horn Speakers" to hopefully spare someone else from going through the agonizing fretting and worrying I've been through these past five months. I'm not naive enough to think that all UMG problems with horns can be resolved with EL34's, but I do think the change in sound was dramatic enough to at least better the situation. You have to remember, in my case, not only did the EL34's remedy the UMG, but it brought out the "Zen" in the Torii and took it to new levels that I'd never experience before.
In closing I would like to thank forum members, RW82 and Lord Soth, who put me on the right track inspiring me to try EL34's and hinting that the EL34's are a good match with Klipsch horns -- and boy were they right!
And a big thank you goes to forum member, Will, who has taken the time via personal messages and even a telephone call to educate me about room acoustics, tube types, and great guidance regarding tube rolling. Just as important, he made me realize that an amp of this caliber can't be just a plug-n-play device like I've been used to with my off-the-shelf tranny amps. The Torii is so damn quick, powerful, resolving, and dynamic, not to mention that your speakers become part of its circuit, you have to do some homework to find the tube set that is optimal for the speakers connected to it.
This forum has some very knowledgeable and generous folks who make this hobby even more rewarding. I'm hoping to be at DecFest again this fall, work allowing, and hope to meet some more of you in person.
Happy listening and may the "Zen" be with you!
Cheers!
Jimmy
PS: I'm open to EL34 suggestions as well as KT77's as I've read they're part of the EL34 family (alas, I'd loose the Hazen Grid effect with the 77's, but you never know