Kana,

Welcome back. Steve said earlier to order a MkIII and then MkIV build will be automatic and specifics can be sorted out later, with plenty of leed time before build time. The Jupiter caps are standard, and we know the KT66 upgrade is 100.

I would just put what you want in the message box of the order form and ask Sarah to let you know pricing details for the extra volume control as they become available along with the approximate build date so you can be sure all is well when it comes up.

This is what I would do anyway if you want to get a place in line locked in. Or call.

UPDATE:  MORE LISTENING TESTS

I had an interesting evening with the TORII MK IV last night.  I played it on my corner horns, which for that amplifier are a worse case scenario when it comes to bass at high volumes. Since the amp likes to put out more current into higher impedances, horns of this design can get a touch boomy.

This very tendency of the amplifier to sound boomy on the corner horns makes the other 12 pair of speakers in our listening room sound better than they actually are…  but nevertheless, it is the worse case scenario you have to design for, so on we marched for the next four hours with the MK IV on the corner horns.  

The new MK IV bass switch really alleviates this tendency with these speakers, so it was of course on the entire time.  And after shifting to more demeaning material, the positive feedback switch was turned off, dropping the dynamics slightly and allowing me to crank the amp a bit harder. Then during the acid test, I used electronic music which has wall cracking low bass at high SPL due to massive compression, I even switched speaker taps with the speaker impedance switch to the softer setting.   These three adjustments kept things tight and clean as the evening matured and the material continued to get more and more challenging.

It is interesting to note, that after four hours I gave up on the EL34's and installed the KT66's that I designed the MK IV to favor. The TORII's tendency to get a little over the top on these speakers had now disappeared and the amplifier became as linear as if there were feedback applied. The midrange and top end and bottom end are virtually perfect now, and at any volume. Nothing changes from modest volumes to louder playback levels and there is a very apparent increase in overall headroom and power.  

Naturally, this was a real thrill as I was well into hour five and playing my challenging tracks to see how well the amplifier maintains it's usable power. Suddenly this simple tube change made everything  twice as good, and I realized I didn't need the speaker impedance switch on the softer setting anymore… so I switched it back and everything got 3dB louder, even fuller, much deeper, and without a trace of strain. It was truly a wow moment…  

Things are getting really fun now… so sucked into the recordings with this latest bust of flavor, another hour went by and I realized I didn't need the bass tighten switch on, so I turned it off. Everything was still fine, nice and tight, but now suddenly even deeper. Again not a hint of strain. It was wow moment no. 2, and I have to say that things are getting amazingly loud without sounding bad… quite the opposite in fact.  (this is btw the epitome of usable power).

Another half hour went by and I realized I hadn't turned on the positive feedback switches yet. So, without further ado, I just turned them on. This was more like a holy-crap movement where I just stood there in the sweet spot of my horns in disbelief at the presence… not to mention the room shifting dynamics that simply felt real.

Ratcheting the performance and sound up three times like that I'd have to equate the experience to a drag race, where you come out of the gate with a nice wheel stand, wind it out and then hit second gear followed by a nice long pull and then hit third gear. You get a little sideways for a moment with the meat on your face pulling back toward your ears from the aggressive pull until everything is a blur… and you then float into your out of body experience. So, clearly the TORII MK IV is a competent space ship like it's predecessors all were, but this one has gears!  

Moral of the story, Tungsol KT66 = MK IV… Just do it.

Thanks for the update Steve. I spent approx. $1,500 stocking up on NOS EL-34's. Do you think there is an improvment upgrading the MK3 while still using EL-34's?

Mike,

I look forward to your impressions of the MkIV transformation. Who knows, those Siemens EL34s might be just the things for your "second" amp!!! Nice tubes, but not a particular fav of mine (I seem to like them all in the right company). So many things make up a system though so who's to know!

Right now in my room the MkIII with cryo'd Mullard EL34 reissues, Amperex orange PQ 6922s, Phillips 5R4YGS, Marconi OB3, and Raytheon OC2 is just blowing my mind...but the secret ingredient is the CSP3 with a 50s GE/RCA 5U4G-ST, Brimar 6BQ7As, and an ERA (Mullard) 6Dj8. My God, now I have 8!!! tube sets to play with.

I am not giving up on the EL34 just yet! But I have not heard the MKIV yet either!

These tests show that that amp still has plenty of flexibility available despite having different controls than the MK III.  That's encouraging.  Steve was doing all this playing with his corner horns, very different speakers than mine.

I wonder if any of those adjustments would be appropriate with my JansZens.  Those I'm sure give the amp a very different look.  Because of lower sensitivity I'll be working to urge the most power from the amp that I can but maximize the sound quality as well.  It looks like those KT66s will be in my future as well.  Exciting experiments await.

I'm fairly certain the Mk III to Mk IV upgrade will be reusing the original white aluminum chassis, after my talk with Sarah a few weeks ago.

Mike

Steve,  Thanks for your clarification about the EL34's!

Mike

So at what point will be have a complete fact sheet on the Mk IV, I am getting kind of dizzy flipping back and forth through all the postings to ingest all this data. I have flipped back and forth between biting the bullet on a Torii or just staying put with what I have. It's not a crappy system by any means, it's just that when I put the SE84SE and it gets broken in again, it's SO BLOODY MAGICAL within it's little 2 watt window. Now that I have ordered the Torii IV and am faced with selling off my pre-amp, power amp and dac, get the new amp and get it broken in. Need to break out my old preamp for the phono section (must use my new Decware SUT which is GREAT) which will be interesting until I can order the Decware phono pre-amp. Exciting times we live in, heh??? Thank you Steve and Team Decware for all you do!!!!

That is a good question. I like the look of the non-painted coils in the back. I would be happy either way but it would be good to know how the unit comes new and what happens when a unit is sent in for upgrade.

Steve has stated that the upgrade will include Jupiter caps. (Which is a very worthwhile upgrade for the Mk III--I've had that done and I don't feel inclined for several reasons to upgrade to a Mk IV).

UPDATE: LISTENING TESTS

Evaluations don't just happen in one evening, so to be objectively fair during this contest between the MK IV and the Mystery amp I am on night three with the MK IV reviewing material I have examined dozens of times on the Mystery Amp, and frankly the MK IV is so good, it's making it almost hard to remember what the mystery amp actually sounded like.  That's what you want in a great amplifier.  Clearly the MK IV has more bodacious bass rendering with an abundance of weight and texture, when compared to the more accurate Mystery Amp, but I have to say I'm not entirely sure which amp is actually more fun to listen to.   And if I remember one of my early posts that I defined success in the inability to decide which amp I would rather listen to on a given evening, then I have to say I'm at that place.  The MK IV is a stratospheric leap above the Mk III.  Like a magnifying glass on the music.  A bar that was set my the Mystery Amp, and the ensuring sibling rivalry that followed created the MK IV.

Frankly I couldn't be more pleased with it evolution.  I believe it's now at it's summit.

It's almost ironic if not funny to remember where it all started.... taking a pair of single ended air gapped output transformers and running them in series to create a low efficiency push pull transformer.

I found out the hard way that in the TORII circuit the output transformers had to match within a phase angle of .005% up to 100,000 Hz to keep from osculating into less than desirable conditions.  It was probably the coolest sounding amp I had built to date.  Sadly I had to build four amps just to find one that was stable enough to ship. The rare few owners of these blue Torri's will tell you how nothing sounds like them. It's a long story, but it just demonstrates why nature has certain rules.   If you bend them too far, you get into the Zen Taboo, Torii Zone and it comes with a price.   The first 25 TORII's sold cost me over $50,000.00.   So You can see why after 15 years and all these revisions, including custom output transformers, I am so pleased to see it finally peak, and what a peak it is.  To even be near the level of the Mystery Amp is a huge accomplishment... and here I am after only three days and having a hard time remembering what the mystery amp sounded like, shows you that we have a serious winner on our hands!

I would say for lower volume listening the pristine but weighty texture of the TORII MK IV is probably more desirable than the Mystery Amp.

Reading Steve's writing is pure audiophile porn. I love it! I keep thinking to myself how does it get better than a MKIII running a pair of Siemens cca's and a quad of 50 year old EL-34's. I know it will be worth the cost and wait… although I may need to attend rehab while my Torii is gone!

I have a MK3 with the Jupiters already installed.  I emailed Sarah regarding my cost to upgrade to MK4.  $450,  does not change the top to a black plate, that would require a complete rewire job.  1-3 week turn-around.

Greg

LR,  per the email steve sent out w/ pics of the mkiv on sept 12,  it won't be until after Decfest when he can update the web page w/ the new price.
Greg

kana813,

The Mystery Amp will be produced.  While I give the edge to the MK IV for lower level listening, the Mystery amp still sounds better with high resolution recordings or analog sources.

Steve

Steve-

I have a MK III Torii with V-Caps.  When I have it upgraded to MK IV would I want to use those?

Jeff

Dear fellow Audiophiles,

There will be an audio "Clash of the Titans" shootout in a few months time.

I managed to get hold of a matched Quad of the legendary GEC Grayglass KT66 NOS power tubes. (If you google "Tubeworld KT66", you can see what they look like)

When I receive my Torii MK4, I shall pit these against my matched Quad of Philips Metal base NOS EL34s.

KT means "kink less".
The KT66 tubes were specially developed by GEC/MOV (UK) to counter the audio sonics of the equally famous power tubes by Philips (European).

I can't wait to receive my Torii MK 4 and settle this audio contest once and for all !

Quote:

"Any time before we pull parts to build your amp.  Usually around weeks 8 to 10.  Send Sarah@decware.com an e-mail or call her at (309) 822 5255.

Base price on the Mystery Amp will be 4695.00 and we will go over any options and prices for those options prior to starting your build. -Steve"


Steve,

Thanks for the info.

I see you're using transformers on the Mystery Amp's input.

Did you know that Audience has a new line of transformers?

http://www.audience-av.com/parts/ait1_description.html

If you'd like to try them, PM me and I'll see if I can get you some samples.

Any new Torii mk4 users will share their impression
Thx!

Dom,

My MkIII has the contemporary base which is 18.5 x 13. With standard feet and Valve Art 274B rectifiers the height is a little under 8 inches. The Chatham 5R4YWG rectifiers in there now are about the same.

Dom,

I designed and built a lot of pottery kilns for many years, so understand the basics of heat and draft.

When you look closely at the Jolida, you see that there is an air space top and bottom on all side pieces of glass. With the heat of the tubes and transformers, heat naturally rising, a convection cycle will start passing heat out the top spaces. This is turn sets up a pull from the spaces below, drawing in cooler, room temperature air, cooling the interior air, tubes and transformers as the upper spaces vent heat.

To a degree, the higher the distance from the bottom space to the top space the better it will create an up draft. But at the same time, the jolida unit has plenty of space above the transformers and tubes to collect the greatest heat before it vents out.

The trick would be making the air space in the top big enough, and the top and bottom side glass spaces tall enough to allow good air flow, optimally cooling/venting the unit.

None-the less, since it is enclosed rather than being open, there is likely some heat build up. I suspect the Jolida instructions tell one not to put this in an enclosed space, and not to touch the glass???

The Torri has more, hotter tubes, but also a lot more horizontal surface area. I think it could work. I might think about going a little overboard with the side spaces and the air space above the transformers and tubes. Maybe make the height  3 or so inches higher than the rectifier tops and make the spaces on the bottom and top of the side glass pieces maybe 1/2 to 5/8". If you worked out a way to hold the glass in place in a secure, but somewhat temporary way, you could start with the spaces on the smaller side, and if it heated up too much, pull the glass and get it cut.

The back glass panel would have to allow for cables, and maybe you would want to look for an elbow adapter for the IEC if there is such a thing. This would upset the balance of air flow, but I imagine it could work fine with the back/bottom space two inches or so to accommodate cables while also letting in more air. Or maybe you would not have to protect the back??? leaving it without a panel.

I am guessing you would want the design to allow for lifting off the top glass and sliding out the side glass pieces for access to the inside.

I would talk with Steve about it, but these are some thoughts. Alternately, a similarly shaped stainless steel mesh box that you could easily lift off would function close to having it out in the air, and with the right design and mesh it could look cool.

Hey Will,

Thank you so much for your input...it's greatly appreciated!!   Since you have experience in this area, your advice will be helpful.  Whether I attempt to construct this myself, or outsource it,  i think it's something that will give me peace of mind.  

While a protective metal cage may be easier to construct,  the glass structure would just be that much nicer and add a touch of class.   I did notice the spacing in the glass panes on the top, bottom, and sides.  I am sure that the heat dissipation was taken into account.  I may need to take some surface temps of the base and the tubes themselves to get a better idea of how to proceed.

Dom