Steve, can you give more details on the new Torii?

This new appearance has me curious.
Can't wait to see what it's going to look like.

Damn….I love it!!

Besides moving the power switches to the front of the amp….I love the addition of the balanced inputs.  The overall design looks really clean.

When I enlarge the photo…I if my eyesight serves me right….I see wording that reads “Tube bias”….a nice big cutout to possibly house a meter….what else?  I’m envious.

Dom

2 input tubes per channel?

OC2 regulation tubes eliminated?

........something to do with the new ultralinearity?

muy interasante

All makes sense, thanks Nigel  [smiley=thumbup.gif]

Nice photos

Seeing that preview photo, I may have to reconsider my knob choice and go with the cream chicken head instead of the gold round. This is so exciting!

Yes, with dual volume, chicken head knobs is recommended.

Since the amp is ultra linear, there is no need to use OA3 for the screen grid because that grid is connected to the ultra linear tap of the output transformer.  So I will use the OA3 for the input tubes instead of the OC3.

Steve

Also, any idea approx. when the MK V will enter into production and you'll be making the big announcement / set up a page on your site with all the details?

click on the image to see full resolution.

So here we are at the beginning stages of the layout and by that I mean wiring layout... Internal parts layout.

This is by far the hardest part of the amp design...  because you are not only considering the voltage paths of everything and the associated magnetic fields, but how easily can it be copied, how easily can it be repaired aka a part be replaced, and how well can it handle 90G impacts during shipping.

As you can see, the layout is symmetrical from the left channel to the right channel.  At this stage we are just wiring all the transformer wires to get them out of the way so we can focus on building the amp.

Over the years what you are looking at is what has become my preferred build style.  I use nylon stand-offs with internal threading (4-40) to receive plated copper eyelets.  This is a bomb-proof design that never comes loose, bends, or caves to the 90G shipping impacts.  It costs a bit more, each white stand-off is almost a buck.

The reason for tonights photo is that it occurred to me as I was soldering this that the ground buss is a factor in the design of all dual mono Decware amplifiers that might be worth chatting about.

There is a 6 inch solid copper 12 AWG wire running down the exact center of the amplifier -- this is the audio ground buss.  The steel chassis will be the shield.  A 10Ohm 5 watt ceramic resistor and a capacitor in parallel will bond the audio ground to the earth ground that is directly connected to the steel chassis.

This ground buss will become the center of a star ground for the entire amplifier, or should I say amplifier(s). The TORII MK5, MK4, MK3, MK2, MK1 have all been dual mono, so that means that it is two complete and separate amplifiers sharing the same chassis.

Naturally the question becomes how is this different than two separate mono blocks? The answer is the ground, and power cord.

Frankly the only thing two power cords can do is offer an opportunity for the resistance between the two to vary. That creates to ground busses that have a small potential between them. That's a recipe for noise and hum and some other nasties.

And in part because of the power cords, the tension of the IEC connectors, the recepticals, and the lengths of each side, and what it runs next to all plays a part in the sound of the amp.  Besides noise, it can effect imaging.

Having a single 6 inch copper audio ground buss for both amplifiers, centered between the amplifiers with exactly the same length of wires between each channel relative to that buss and everything else sets up a potential for much tighter imaging focus and blacker backgrounds.

Our Zen TORII MK1~MK5 as well as the ZMA are all built this way, with a very deliberately symmetrical and exactly balanced audio ground buss that floats  slightly above earth ground helping it to reject noise and at the same liberate it from earth just enough to create a bit of flex that adds some life to the dynamics of the amplifier.

So while in this picture it looks like almost nothing has been done yet, it reality almost everything has been done.  Now it's just the details.

The NC wires you see on each channel are the various voltage taps for the world voltage power transformers... that way the amplifier can be easily re-wired for 100 volts, 115 volts, 120 volts, 220, 230, 240 volts 50/60 HZ.  Many of our customers live oversees for several years and then move back home for their job.  This makes it possible to have the amp wired for any voltage.

The switches you see, are all DPDT silver contact switches, the best Mountain brand for over 20 years.  These are always used in Decware amps and wired with both halves of the switches in parallel so that there is never less than two separate contacts on every switch.  We don't have any SPST switches like this in the building.  

So as you study this image, and see the transformers both fully wired except for one wire on each side, it is time to study the schematic, (there isn't one) and each and every part (resistors/capacitors) and exactly how it's going to be placed in 3D space.

The wires you see bundled together are alternating current of different voltages. By wrapping them the field interaction smears the phase angles and helps homogenize the ripple.  Rectified and filtered DC lines will be clear of these AC wires with nothing but air and space around each feed in 3D space.

3D Space is about magnetic fields around each wire, part lead, and part.  On a circuit board the board combines with each part to add capacitance and the fields follow the flat traces creating a fairly 2D interaction on those fields. It is able to be calculated whereas 3D space is not, only in the mind of the guy who lays the parts out in the working bench sample, which is what you are watching develop here.

I will be leaving these images at their 5 Megabyte size so that when you click on them you can see details that simply don't live in the 800 pixel images in this post.

Steve

outstanding.

thanks Steve, for that fascinating write-up.

HK,

You’re exactly right, as a Decware first-timer, and being one of those in the que for a Torii IV, I could not be happier or more impressed. My brother-in-law has been a Decware devotee for years, and I’ve been waiting eagerly to be able to finally join the club myself.

The 7/8 month wait will definitely be worth it.

Steve,

What an amazing design!!  Just when I thought this amp has reached its pinnacle, you come along and drop  a bomb.  If I already didn’t love my MKIV 25th, I would sell it and jump back into this new design.  

For those on the waitlist, congrats on getting this that this major upgrade.   I wish I could have attended Decfest this year to see and hear this new amp in person.  

Dom

Yes, It will be rated at 25 watts, just as before.

The external fuse holders are four times the cost of the internal rectifier fuse board that we presently use however since a fair number of people have actually blown the internal fuses on their amplifiers over the years when a rectifier tube miss-behaves, I thought I would try something new and make them external.

Additionally, the mains fuse is now dual, meaning one per channel.  This will help you diagnose amplifier problems by seeing which channel took out the fuse and which fuse it was.

Steve

Hello to you all and i'm sorry to come back that late. I only wanted to check the amplifier waiting list and then saw this topic.

That's amazing! It seem to me that some members who replied to this post and are on the waiting list with a TorIIMKIV expect to be automatically upgraded to the MKV. I somehow can't believe that this is possible without an additional payment for the upgraded parts like the fuse box, balanced inputs a.s.o.

As the new MKV is not yet finished and someone wants an upgrade to MKV, will there be a step back on the waiting list?

And the waiting list. I checked it nearly every day, at work or at home. At home with a decade old Imac, at work with an actual version of a windows PC. If i click the link (at home or at work), a blank window opens, a black Decware image with a black thin loading line below that runs from left to right is shown. After a second everything is gone, but the list won't show up, refreshing the site won't help. Until now i had no difficulties.  :-[

I know that this won't fit in these topic, but as i'm also waiting for some month now and my solid state amp is defect, i only listened to the kitchen radio and on the way to work in the car. Well, that is not funny and somewhere else i found a topic with recommendations on cheap tube amps to get over the waiting time. The small little amp that was posted there was nowhere available. I looked around and found a cheap used tube amp, which sadly seems also no longer available new and i don't know the price for a new unit. I paid 235 € with two new additional PSVANE EL-34 B tubes.
It is a Gemtune-X1 amp. Never heard of that brand before. It's small and puts out 2 x 8 Watt. I didn't expect much, but even with stock power cord to me, the amp sounds amazing. It has only one input, but with an additional add-on input switch, maybe remote controlled if something like that exists, anyone can build a very cheap system that sounds really fine with fitting speakers. The amp has speaker outputs for 4 and 8 ohm (only banana plugs). I took out the fuse box and it even  contains a second fuse for replacement! Can't recall any amp that i have seen or read about that offers that. Please take a look at the image of the amp.

Did somebody read the review of the Doshi Audio Evo monoblocks in the May issue of stereophile? $ 40.000 for the amps and the power knob on one of them is out of order? Absolutely unbelievable, and i definitely don't like the design of it too, but that's a matter of taste.

And one last question. Anybody gave some thoughts on how to keep the tube amp dust free or the best way to clean the amp? I don't think that you want to take out all tubes every month or so to clean the device. I thought about using an air pressure can in one hand and the vacuum cleaner in the other to collect all the dust from the air, but i haven't tried that. I place a lightweight cloth over my turntable when it is not in use. But that is also not the best solution. An acrylic hood seems also not practical, as my amp will not have a place on top of the rack. So that won't work for me. Any ideas welcome and much appreciated.
Thank you all.

Hello Lon,

when i read through the post i haven't seen, or overread the statement that there are no additional cost for an upgrade. If so, wow, Steve, thanks a thousand times! Sorry and i'll reread the complete post again.

I had no idea if the Decware amps come with replacement fuses or not, and i don't think that this is an important issue. It was only remarkable for me, to see something included in such a cheap amp.

By now i can only say that "most" components, regardless of price, come without a second fuse.

Thanks for the fast reply and good night, good evening or good morning for now. (here it is 10:30 p.m.)

Lon - From the Decware Concept Speakers post:

"Yes, there will be a TORII MK5 once the steel gets here. Everyone with a recent TORII MK4 on order will be getting a MK5 at the MK4 price. It's going to be sweet. I made the TORII JRv2 so good there was really little incentive to move up to a TORII MK4, and sonically the incentive won't be huge over a TORII JRv2, but visually and in other ways it will be worth the extra bucks.

If not for all the delays in supply lines this amplifier would have been in the final stages of listening in the production chassis by now. Nothing I can do about it but wait for chassis."

Keeping the amps clean, Steve suggests using a soft bristle paint brush and brush the dust off. I also suggest a HEPA air filter that is rated much larger than the room. Run when you are not listening to the system.

I have an APPJ el84 amp 3.5w I use with the tiny radials. I bought it used for $85 shipped with two sets of tubes. it’s a great little amp for less than $100! Tomorrow I’m loaning it to my sister for her Caintuck F15’s because the Bluesound Powernode “doesn’t sound good” and she wants some of that “sweet tube magic”. She got spoiled by borrowing a UFO25th for a few months.

APPJ and Gemtune are the same products AFAIK.

There might be some confusion about the 2 fuses, or only I am . Most of the modern DECWARE amps have the standard IEC fuse, and a fuse protecting the amp if the rectifier blows. The CSP3 has 4 fuses actually.

The MKV has the "rectifier" fuse is now relocated for easy access. MKIV you needed to remove all the tubes, RCAs, speaker cables and PC. Then unscrew all the screws and take the amp apart. The amount of high voltage caps can kill a person who doesn't know what they are doing. vs a simple push and twist to remove and check / replace the fuse.

Monday morning our online software (ZOHO) updated itself and many of the features we rely on disappeared, and other things changed.  Basically access to our data was held hostage.  But worse, even when the yearly ransom was paid we had to spend two days fixing everything. This included the build sheet. And the old link quit working. That alone had our phone ringing off the hook for two days. Anyway, here is the new link to the real-time build sheet:

https://creatorapp.zohopublic.com/decwarehighfidelity/decware/report-perma/Ampli...

Steve

I have them now.  I am about half-way through the build of the first production sample.

Click on image for full size



This is the magical point where all the transformers are installed and the long wires from each are buttoned up and we are now ready to actually build the amp...

The UFO output transformers feature silver plated copper wire with Teflon, and we makes the leads so long that when we cut them to length for the build, we have enough left over to wire all the critical parts of the signal path and ground path in silver.  So the blue, blue/yel, brown, brown/yel, red, light green wires are all silver/Teflon.  This represents the pates and cathodes of the output tubes and the transformers between the tubes and loudspeaker.

So the next step is to begin installing the filter caps.  I will be using an Atom Sprague 8uf cap for each channel as the first section and then 47uf/500V F&T German caps for the rest.  Everything is dual mono, so everything is done twice.

As you watch this evolve and the layout I hope some of you will intuitively see why it so superior to using circuit boards, which you can imagine how much they would simply the build.

Click on image to see full size



A few changes...  Each tube has to have it's own bias resistor so the big blue ones are gone, and now we have black 6.5W DALE wire wound resistors for each tube wired to a silver contact switch using a DPDT switch for each tube so that we can parallel both sides of the switch to double the contact area and current rating.  Silver wire connects the cathodes of each output tube to the resistors which are directly wired to switches.  The switches allow the user to connect the cathode to meter one tube at a time, a pair of tubes at a time, or all of the tubes at once to see the current draw.  They also can connect directly to ground bypassing the meter at which point the meter reads zero.

In this sample the meter is not made by us, so it is not back-lit nor is it colored like the illustrations I showed earlier.  But it will work and look great until our custom meters arrive.

Steve,

I’m sitting here at work in awe! This amp will be kickass when it’s done!!  If it were possible… I’m sure all of us would love to see a few video clips of this build as you work on the amp….just as long as it doesn’t  give away your trade secrets.  Either way…please keep the posts coming!!

Dom

Steve,

I hope you are keeping detailed notes about the "New Torii MK V" build, to help with the development of the "Production SOP."

What's the single meter for?

That's such a thing of beauty.  When are you going to make a glass top amp?

Been watching this thread on the new V… ugh. I need someone to stop me from joining the madness of placing an order for one.  I’m smitten.  

Hang in there Steve-O.  The family is behind you 100%!

Just concentrate on what you know the final result will be😊

We appreciate all that you do!!!

click on image to see full size.  If you do, you will see the laminations in the right hand output transformer... each of those is actually three laminations.  So three dark, three light, and so on.

And I'm back.  The first thing I did wrong was hook two resistors to the wrong spot on each channel.  Of all the resistors in the amplifier, there are only two that if omitted or misconnected can open the portal.

The Portal is a passage to underworld, a world where physics are bent around the humor of the punisher...  For example, this particular mistake can take a DC power supply in an amplifier that is only capable of putting out 350 volts under load and 450 volts with no load climb all the way up to 600~700 volts or more. I never had the nuts to see how high it would go before the entire amplifier exploded in my face, so I usually killed it at 600. Remember an amplifier is an oscillator designed not to oscillate ; ).

Other things the portal can make happen is a perfectly working amplifier to really mess with you or one that will not pass a signal at all or any combination of the two depending on the humor of the punishers.  I said punishers this time (plural) because by now there are several standing around the crystal pool watching you.

In the case of this amp, it did neither. Instead it found something new and caused the cathode biased tubes to climb to hundreds of mills until smoke started coming off the cathode resistors and I had to pull the plug.

No worries, I found this one fairly quickly, having recognized that when something impossible is happening, the portal has been opened and the only way to open the portal is to leave out the grid bias resistors that follow the coupling-caps. Without that reference, turning on the amp immediately opens the portal. So I knew to look at those and sure enough I had them wired on the wrong side of the caps.

This is what happens when doing a new layout, because you are highly focused on the layout rather than the circuit and often make stupid mistakes.

My only thought after finding this, is that the amp probably will work now.  It didn't.  Still wouldn't pass a signal.  This is about the time when you know it's time to buckle in and ride it out, or walk away.  

The next day I gave it another shot and found that the reason it would only put out 500 milliwatts at full volume was because I forgot to wire the high voltage to cathode follower tube plates. HA, this is just like when I forget to plug an amplifier into the wall and wonder why the damn thing won't turn on... this is going to be easy.  

My only thought after finding this, is that the amp probably will work now. It didn't. Still wouldn't pass a signal. This is about the time you have to balance the negative forces at play with some profanity. Without profanity man would still be trying to get the wheel to work. So I did that.  

Sadly the amp didn't fix itself and jump to life so let it set for another day.

Today I fixed it.

Here's what happened... Even though this amp uses the exact front-end of a Zen Mystery Amp, I deliberately did not look at our working sample of the ZMA because I wanted to invent a completely different internal layout without being influenced by the original one on the ZMA. So instead I used my schematic of the ZMA to built the front-end and as a result did in fact come up with a better layout.

During that experience I became obsessed with the .1uf cap used in the tail of the long tail splitter (phase inverter).  I became compelled for some reason to revisit it. Why did I make it .1uf? Can it be smaller?  After diving down that worm hole I found out I made it .1uf because that is the only value that will work properly to balance out the low frequency response of the phase inverter.  I was also obsessed about where to locate the cap in the layout. It really became all about the cap there at the end...

This obsession with the cap turned out to be a misinterpretation of a warning from the Audio Gods who were trying to tell me there was a problem with that cap. The problem was that I drew the schematic wrong. Specifically when I drew the schematic, I drew on lead of this cap connected to the wrong place so when I followed the schematic I build the new amp wrong and wasted a lot of time comparing my work to the schematic in defiance unable to find anything wrong.

Once I looked at the ZMA, I could instantly see what happened.

So tonight it is on the bench doing some chin-ups as I write this. I will listen to it tomorrow.

I am pleased to report the biggest challenge being to get the 'TORII Harmonics' right, and at 1 watt they nearly perfectly match a Zen Triode amplifier, which is actually better than the TORII MK4, also, the distortion is lower.  Depending on tubes used, the range is between 0.2% and 1% total THD. Of course if you stripped out that first harmonic which we all so dearly love, the figure would drop closer to 0.02%.  

This will be a rich textured amp just as it has always been but with far more forgiving front-end with even lower distortion. The bandwidth also improves with the UFO transformers and overall resolution will be higher.

This weekend will be nice as I will start breaking it in tomorrow at work and by Friday night, we'll be ready to hear the results.

P.S.

I want you all to know that the hellish feeling of trying to fix something that you can't find anything wrong with happens many times to all of us as we put together your amplifies via this painful process. Circuit boards eliminate this. You can see why Decware amplifiers sound like Decware amplifiers. It takes real men to face this dragon on a regular basis and always come out victorious because there is no other choice. The longest the Audio Gods will punish you is 24 total hours.  That's basically four work days. But they can be defeated in numbers, so if two or three of us look it over, the hours melt off quickly. That's how we overcome the dragons during the daytime, but this particular project like all new amps, I just fight alone so as not to burden my crew.

Steve

Steve, another fascinating insight into the pain and delight of a mad scientist Thanks for sharing.

I hope this doesn't sound nitpicky on the visuals, will you by any chance be revising what's going on with the print around the volume knobs? Might there be a consideration to make it considerably less dominant, or removed altogether like your other amps?

Wow, its sounding like this amp is going to be incredible! I am really looking forward to having one.

Brad

Regarding the print around the knobs, it is designed for chicken head knobs to be highly functional since there are dual controls. The reason I went with white is so that in the dark from only the glow of the tubes and meters you would be able to see the numbers. During the day it is a lot of contrast and gray would have looked more appropriate. That said, a 38~42mm knob with a 1/4 inch shaft will fit perfectly and cover it. The knobs we use on the ZTPRE are a fine example of what I'm referring to.

I find the volume notation to be a nice improvement.
 
"This is about the time you have to balance the negative forces at play with some profanity.  Without profanity man would still be trying to get the wheel to work.  So I did that."  

This is my favorite part of a most entertaining write-up.
Thanks, Steve.

Brian

Here is a pic of a 38mm knob because that's what I have in stock.  A 42mm knob would completely hide the indexing for those who don't like it.



Just put it in the listening room. . Now after the 20 minute OA3 warm-up there is no question that this sounds better than the Torii Jr., and it may even be better sounding than the ZMA (but 1/2 the power). If that turns out to be true my goal has been reached. To offer 3 different amplifiers.  Nevertheless I am surprised that it sounds better than a TORII JRv2... We can't say it's the output transformers, because they are the same.  The only differences are the power supplies and the phase-inverter. I'm not sure yet which is responsible for what I'm hearing, but it is very compelling. Not even the original Blue TORII's were this good.

I'm going to have genuine fun this year at DECFEST watching peoples faces when they hear the combination of this amplifier, the new Tube Tots (speakers) and the HOLO MAY DAC backing it all up. It's just hard to believe how good it is.

Ear Candy...

Absolutely Stunning…
Amazing how you can continue to Best the Best!
Highest Regards…

We can offer this amp with or without silk screen the way it currently sits...  The chassis is a mirror image, so either the screened side or the non-screen side can be used.  

Steve

This new design is phenomenal !!   The layout is so clean.  I love that the bigger chassis spreads the tubes out more and makes it easier to handle.  The larger knobs fit nicely in the new layout as well.  

I’m sure other Torii owner’s like myself are chomping at the bit waiting to hear how this compares to the MKIV.  Interesting that you feel this may even be better sounding than the ZMA at half the power.  Please elaborate.

Dom



 

Hi Derekinla,

Welcome the forum and welcome to the family.  At this stage it is too early to say.  I'm still trying to wrap my head around the differences.  When I listen to it, I find I have to remind myself that it doesn't have any anniversary mods yet.

As far as my comparison to the ZMA, I think I am zeroing in on the output transformers.  I think that is what I am hearing.  The combination of the ZMA phase splitter on a cathode biased amp using the UFO output transformers.  It's a unique combination that looks like it's going to have it's own sound.


TORII JRv2 - original direct-coupled phase splitter, single power supply, 20 Watt UFO transformers, cathode bias.

TORII MK4 - original direct-coupled phase splitter, dual power supply, 25 Watt Non-UFO transformers, cathode bias.

TORII MK5 - long tail direct-coupled phase splitter, dual power supplies, 20 Watt UFO transformers, cathode bias, meter.

ZMA - long tail direct-coupled phase splitter, dual power supplies, 40 Watt Non-UFO transformers, fixed bias, meters.



As far as the nitty gritty sound quality differences between them with or without anniversary mods, let me say this: At AXPONA or a similar audio show environment all four amplifiers would sound the same so long as 20 watts was enough power.  The subtle differences would become apparent in your quiet home, but even then would be clearly in the category of subtle, so it's not like you can pick the wrong amplifier based on sound quality or sound signature. You should all know me by now, I make everything sound a certain way or I don't make it. It's the Decware sound, it's baked right in. It's a tight family where as you get to know each amp, little personality changes begin to appear and you may develop a clear favorite or you may not.

Steve

OK, Hold the phone... something is wrong.  After 12 hours and a bit of time this evening to listen, there is no way this sound can be from any of the things I've mentioned.  What I am hearing is something new, and not a combination of things from the other amps.  I'm sorry this sounds too good, something is wrong.  Something has happened.

Thank you Steve for the detailed feedback to my question and the technical explanation of your incredible discovery! Can the Cathode resistors be merged in the Torii Jr to take advantage of this sonic breakthrough from the audio gods? Could this be a sort of CCE21 update to bring the Torii Jr 2.0 to V2.1?

Wow. Looks as if this will be a great amp. I'm broke as far as audio equipment goes, so I'm glad I am so very happy with my Monoblocks and remember that whenever I've compared the low-powered amps to the higher-powered Decware amps I've preferred the SET sound. (And I am so enjoyng just listening to music and not being audio analytical!) But there are going to be many happy users of this amp next year!

Of course I will gradually play with this on the TORII JR and MK4 to see if it has the same effect.  A meter shouldn't be required in theory, only a resistor but we shall see.

Steve

Yup.

Archie, I'm guessing you are saying that in jest.  Increase from 40 watts to 50 watts is ~1db increase in SPL  ;D

Also in theory 25 Watts to 20 Watts in about ~1db SPL decrease.

Kirk,

Is there still more to be extracted from the K-horns... I say yes. Is a new amp the answer? guessing no, If you like the SET UFO2 sound stick with it. I've spent a bunch of time with the SET, PP and ultra linear amps from DECWARE. I prefer the PP / Ultra linear sound. All three have fantastic holography, speed, etc. Lon has owned both Torii and UFO amps and prefers the SET sound.

Without knowing your systems and room setup, acoustic treatment is the best thing you can do.

Cables are also important.

Glowing tubes makes me happy too

click on image to see full size

Hehe... so tonight I'm seeing how hot I can get it. Literally. To that effect I switched to the Corner Horns and put a ZROCK2 in front of it... and turned it ALL THE WAY UP. Have never done that before. Was fully expecting it to completely crap on itself, but the thought "what if someone at the fest turned this thing all the way up" and then it was time to just see what WOULD happen.

So I turned the ZROCK2 all the way up, shoved about 6 volts up it's ass with a ZBIT and turned the amplifier all the way up.  

I had to run out of the room and go and get a witness. No shit. I really did. God, I can't wait until I get time to make some videos... this would have been a good one.  

The bass is so F'IN tight with a ZROCK2 trying to drive it into the wall and it just won't crash. I'm so glad I stuck with 0.022uf Miflex caps instead of going larger.  

Now I'm almost afraid to listen to this amp on my ZF15L Zen Master Series 100dB open baffles...  I might not ever be able to come back down, and be endlessly stuck outside my body. Could be dangerous. Leave it for later.

The bass that came out of these speakers (my corner horns) https://youtu.be/WvP2f-Ls4ws -- the video is of the corner horns. What I heard tonight made that sound silly. I've never heard 20 watts do that in my lifetime, it was just insane. There would be no way to record that on the phone I use for most of the videos. It was 10dB louder than the phone can handle. We would have to use the hi-res recorder, and I think we will.  

I'll promise you this... if you were here, and heard and felt what we just experienced there is no way you would believe it came from two 6 inch drivers on 20 watts without any subwoofers. NO ONE would believe it.

Wow, that was a special treat... didn't see that one coming! I guess that means the amp is done. We'll start building them next week.

This thing rocks every category. Especially the imaging and liquidity. Damn it. Now I'm going to have to see if I can make the JR do it.

So tonight after listening exclusively to the Tube Tots, which are tiny speakers with dual 4 inch drivers, I went to the corner horns 36 times their size and contrast was so great I just about shit myself. Also hearing the TORII MK5 make the corner horns sound great like the TORII JR and ZMA was something I can't really put words to. Hehe, these two items just didn't get along. The Torii MK1, 2, 3, 4 all hated these speakers. For almost 20 years it has annoyed me because it sounded so good in every way except a hint of bass bloat with these horns. My first "I'll Fix YOU" was the ZMA. And boy did that fix it. My second "I'll Fix YOU" was the TORII JR. And that fixed it equally well at half the cost.  This is my Third and final... problem solved and check mate.

A little behind the scenes soap opera for you.

If I was in my 30's right now this would make me run out in the garage and build a 9 foot high pair of corner horns and put an F15 driver in each one. I've never wanted to hear that more than I do right now, and with a ZROCK2 all the way up playing electronic bass music. If you can imagine a 9 foot heigh pair of these horns, with a footprint of about 4.5 feet x 4.5 feet glued into the corners of your large room....  I know I would have done this then, because on a similarly inspired urge I built a concrete bass horn around my furnace in a 150 year old basement. With a single 12 inch driver and 20 watts I put 22 cracks in the basement concrete glaze coat over the bricks.  

A retarded girl walking in the park saw me stop at the lights with a load of particle board in my old pickup truck. I accidentally put it in granny gear which you never do with any real horsepower and it had a really hot 302 Cleveland small block in it.  Light turned green I let out the clutch to go and the truck shot forward and the 10 sheets of particle board was still setting motionless in the air behind the truck were it was parked for the light. When like a cartoon it realized there is gravity it crashed to ground and shattered like glass all over the intersection. To make matters worse I had an entire pallet of concrete bags on top of it that were also now neatly stacked on the pallet in the middle of the intersection on top of the splattered particle board. No shit. It was surreal.

She helped me put everything back in my truck while 4 men stood and watched us from the gas station across the street.

I'll never forget her.

Anyway, many from the early DECFEST days will remember that horn. You would walk inside it. And since we're making a reference to age here, you should know that before I went to bed that night even after the disaster on the way home, the horn was completed and concrete was curing. If that happened now, it's doubtful that anything would have happened until the next day at best... why is that?

You know an amp is good when it makes you want get crazy again : )

Steve

Hey Steve, great to hear the bass dept is a wrap! My Omega single drivers are 6.5",  so about the same size. Sounds like I can sell the Deephemp 8 sub. Nice.

My bass and volume needs will finally be addressed. RESERVE POWER. With the Taboo MK 4 sounding great and fully fleshed on many recordings [acoustic guitar, vocals, jazz, classical chamber] and somewhat thin on too many others, even with the zrock2-25th  [anything rock oriented, classical symphony], it is plain too weak at 3.2 watts. No way around that without RESERVE POWER. So selling it and replacing with this creation should solve those woes. And yes, my speakers are plenty efficient at 95db.

Steve, can't wait to hear what you think of the overall performance top to bottom with your 25th A mod  

Brad

Kirk,

That is a valid question - and one I hope Steve will comment on.

Steve, for me, the real question would be, how would this amp compare to others in the stable, in the 70db - 85db range?

I know it’s got to be pretty cool to hear this setup at max levels, but I almost never listen over 85db anymore. I’m much more interested in mid level volume quality.

So, my question is, for us Geritol consuming folks, does this new setup have much better depth, density, etc., at mid volumes, than the lower watt amps in the stable?

Quote:


100%.

The only amplifiers we make that don't are the 12K 60W mono blocks. Those need to be turned up a bit to open up.

Steve

Hey CAJames.  Not necessarily looking for more watts.  I am relatively new to this game and still recovering from the shock and awe of SET+Khorns in my room.  I am mad at myself for missing out on this sound for far too long.  

I am coming off of a solid state amp connected to bookshelf speakers.  I should have made this plunge long ago. Can't help but wonder is there still more being left on the table?  Would a Torii or ZMA take me to yet another place?

(writing this and was just startled by Lindsey Buckingham's guitar on Never Going Back Again  wow)

Hey Kirk,

If it really isn't about watts then I would say this (although others are much better equipped to go into detail than me): the higher power push-pull amps are different, but certainly not "better." Some prefer the PP sound while but others of us prefer the SET sound. It think it is fair to say with the right speakers the SETs are the last word in speed and transparency and frequency extension so if that is what you are looking for I don't think you can do better than what you have now, except see below. But there are plenty of threads throughout the forums on those differences.

However, there are maybe some other things you can do to get even better performance without switching amps. Did you get your amp with the anniversary mods? If not I would say it is a no-brainer to send it back to Decware for the update. That will absolutely get more out of your K-horns. (Or instead of getting a higher powered Decware amp get the 25th anniversary edition UFO, which would really take it to the max). The other option would be to explore tube rolling. Again there are many threads on this topic and, just like with everything else in audio, you can spend as much $$$ as you want on heritage tubes but many of us have found we can really customize the sound to exactly our liking with just the right tube set.

I don't know if this was helpful or just confusing but good luck with your quest. Finding Decware is a great place to start (or finish).

Well said, CA. The anniversary mods take it to the next level. I had mine done and could not be happier.

Tube rolling will further refine the sound. And quality speaker cable and interconnects bring out the very best the amp has to offer. Everything in the chain matters.

Great advice all.  Thanks so much.  

A bias resistor mod - it is a possibility but I will need more time to be sure it has the same effect as it appears to have in the MK5.  If it makes a difference we'll offer it.  No time soon however, we will wait until things slow down a bit.

So far the testing in the MK5 has been with some inexpensive Chinese tubes which get dark and gassy in a few days, but sound quite good.  Then I put ElectroHamonix in it, and they have more top end sizzle and more bass thump.

Tonight I compared it to the ZMA to see which amp sounds better.  The ZMA sounded better.  So I put the particular set of tubes from the ZMA into the MK5 and now it sounds so close I will have go back and forth a bit to figure out if that's actually the case or if was the tubes.

The bias meter and switch set up is working so well I am loving it.  It's nice to see the total milliamps that the output tubes are drawing at a glance as well as the various combintations.

We are starting production on the amp now, hoping that the custom meters arrive before the amps hit QC.  If not it is possible to ship with non-colored meters like in the pictures I've posted, so it will be the customers choice to wait or take the more generic meter when that time comes.

My intension is to ship it with Russian EL34 or KT66, perhaps either.  Will depend on supply.

Steve

By having both amps on for the same number of hours, and by using the same tubes in both I got a fair comparison between the two, except it wasn't a fair comparison because the ZMA has many hundreds of hours on it and the MK 5 is just passing about 200.  More importantly the ZMA has anniversary mods, and the MK5 does not.  The ZMA with anniversary mods is in almost a different league.

So we will have to wait until we have one with anniversary mods and burned-in to make a second comparison.  My guess is in the final analysis the ZMA will always win because it's power supply design is direct drive with almost 10 times the energy storage.

It's a joy to listen to on edgy or articulate speakers because it has no edge and leads the way in articulation.  

The difference between 20 and 40 watts is only 3dB, and the TORII's would be better at driving low impedances while the ZMA would be better with higher impedances so the scale can tilt either way between the two depending on speakers used.  

Hope that helps.

Steve

What tubes are you running in the ZMA?  I suspect KT66s.  Have you ever tried 7027As?

I can't afford NOS 7027As but the Tungsol version seems nice.  I'd love to hear your impressions of that tube.  It's not expensive and could easily be supplied if so desired.  I bias mine at 64 ma.

Steve, I ordered a pair of GL KT77's a few days before I read you really enjoyed the KT77's and are considering offering them as a premium option.

I've had 2 quads with a bad tube in a month. First 1 tube went bad in 3 weeks. Second quad from a different seller 1 tube went bad in 2 days.

Both cases the tube started to rattle, the tube rattle then was transmitted through one channel.

Is this common with the GL KT77's or a string of bad luck?

I've never had an issue like this with the KT66's, The KT77's do sound much better with my setup.

In terms of the silkscreen.... is there an example of what that might look like?

The photos of the current MKV.......is that with, or without? I am not sure if it was already mentioned.

I have an MKV on order and am trying to decided which direction I want to go when I reach out to Sarah.

Thank you!

Brad -

Thanks very much.  I thought that was what Steve may have meant, but wanted to make sure I wasn't misreading/misinterpreting.


Andrew

My plan is to use the stepped attenuators and count the clicks.

Gorgeous! Stellar work, I can’t wait for my mine to arrive.

What a beast!

Me too!! Haha, I’m in the 550’s.