Sometimes a picture is worth a thousand words.  This is tonights post:




(click to enlarge)

-Steve

Wow that's one BAD MOTHER of a tube. Your amps are already beautiful as it is, but a new design with a pair of these beauts gleaming atop in all of their ethereal glow...well, that's gonna be something. Not to mention the sound...

Your analogy makes perfectly good sense Steve.
Expanding it a bit brought to mind a comparison between straight pipes on a motorcycle as compared to one with a muffler. The noise from straight pipes will disrupt ambient serenity for all whilst diffused noise, created with a muffler cut into the pipe, preserves said peace. Straight pipes sound cool at first but quickly become annoying over time/spaced time.
John

Giggsy-

That’s an interesting question. My guess would be the answer is yes, but you’d have to dramatically increase the size of the flashlight ?? Maybe you’re talking a spotlight at that point? Just spitballing here.

I can appreciate that sentiment, but if I'm getting a Decware amp, I want it to be as best as it can possibly be.

Given his amp's successful propensity for tube rolling, I would think that using various tubes wouldn't be that big of a deal. That's assuming there's an option to buy tubeless.

I'm guessing with WE tubes, the 300b would be comparable to a loaded Torii MKV. And yes, that's an expensive amp in its own rite--but not so when compared to the vast majority of "high fidelity" equipment.

Quote:


I think most tube amps, including Decware sound better with high dollar "heritage" tubes. A lot of us use more expensive e.g. input tubes or rectifiers than the stock tubes and don't regret the upgrade. I expect the same will hold true for 300B tubes: sounds great with the Gold Lions Steve has been using but will sound even better with WEs or Takatsuki or other fancy current production and probably sound better stiill with real NOS 300Bs.

The 300B amp is based on the SE34I.6,  plus a couple hundred bucks or so for 300B tubes over EL34s and I'd guess 2200ish dollars to start.

As of this weekend I probably missed that by as much as a grand...

Make no mistake, while obviously affordable compared to higher priced 300B amps that won't sound as good, there is no attempt made to create a budget 300B amp. There are literally hundreds of them on the market right now, at every price point.  

At the same time there is no effort to make power with it. If you're looking for an 8 or 10 watt amp, look elsewhere.

My motivation (against all this pressure from great reviews) is to make the best sounding 300B experience possible. I don't believe it has to cost 30 grand or even 10 but I suspect by the time you get the WE tubes, and a decent power cord for it you'll be a touch over 5 grand.  

It is specifically voiced for the WE300B which is the worlds reference. Since all copies strive to be like the original - the amp has to be voiced for the original. That said, it will be sold without the output tubes and buyers are welcome to use what they can afford. There are some very attractive sounding 300B's from Shugang in China, their lower lest costly model. The higher dollar ones don't have the same magic according to reports, so if this is true, and it probably is, someone could get a fabulous sound for around $200 for the pair.

Please don't let his start a conversation about prices and features etc. ,etc, it's WAY TO EARLY for any of that. I haven't even committed to a chassis design and am only now evaluating what I think will be the final circuit.

Steve : )

UPDATE 5/1/22

Tonight I am listening to what will no doubt be considered the best sounding amplifier Decware ever built. If you can live with 4 clean watts and some docile very soft hum on 100dB speakers than fasten your seat belt because it's about to get really real. When I started Decware we had Drool towels for people who heard the first Zen Triode. With this amp I'm going to have to recommend Depends.


I took a giant leap this weekend. I have been evaluating it with and without a preamp and with and without a ZROCK2 set flat. Those of you who own a ZROCK2 have no doubt found the magic spot on the dial at about 1:15 where magic happens. This position actually measures flat. It occurs before there is any bass boost or treble cut. The midrange, texture and density of a ZROCK2 set here is so over the top no one who owns one can live without it.


It should be pretty obvious that if you're going to build an amplifier for a pair of output tubes that cost $700 a piece that it's going to have to sound as good or preferably better than our current reference the SE84UFO25. So that is the mind set, and it has taken me on a journey of realization about the sound I want. For example, I start with the question 'What is the best sound I can get in here' and then look at the gear used. Well, it has basically been the SE84UFO25 paired with the CSP325 matching preamp. The preamp adds so much beauty and density to the sound that when you hear it in front of most any amplifier, you will want it. So the reality is that for the best sound, you want both. And a good power cord for each, as well as interconnects.

But as good as that is, if I really want to wet myself, I'll get out a ZROCK2 and put it in front of the preamp. I'll set it to that magic spot which is flat, and just shit my pants at what the three components create! So add another power cord, and another pair of interconnects.  As well, don't forget that you need full anniversary mods with the tube regulation inside. I'm pretty sure with the cables and shipping that's getting close to $10K.

So that is the reference, and I am directly A/B this amplifier design with that.  

When we left off, I had mentioned that the amp already sounds like it has the preamp because of the 300B tubes. It's like free density. Well it's not free, but it actually costs half as much as the preamp.

I have been enjoying it all week with no preamp and then that what if moment happened and I stuck the ZROCK2 on it. This was a mind numbing moment because it offered the same gain I was getting from my favorite settings on the CSP325, and that insane midrange dimensionality that once you hear it you can't live without it. Only now it's magnified. It's like it is in sync with the 300B and everything just shifted to sounding lucid and completely real.  

Haha, it's a good thing I'm experienced at blowing my own mind, because you can't just jump into stuff like this without a lot of seasoning.


THE PLAN

Ok here's the plan come late Friday night - measure the exact values of where I set a ZROCK2 and install one inside the amp set exactly that way. This will be the needed gain stage  giving my around 5 volts (that I will later compress) for every volt of input and put the input sensitivity just ahead of the Zen Triode SE84 series and even the SE34I. So this is what I did. I recreated the exact circuit with the exact settings inside the amplifier and added an additional tube to the front of the chassis. The tube is a 12AU7.  This compliments the 6922 signature so beautifully not to mention opens an entire world of tube rolling. A single tube will change the sound of your amp and there are millions of them on the planet.

Like a ZROCK2, the tube is at full blast all the time. The output of the tube feeds the level control which in this case is the input of the amplifier, or put another way, the volume control.  This is what we refer to as riding the gain.  The input to the amplifier is raised from 2 volts max to 10 volts and then squeezed back down to 2 volts. This creates dynamics and speed.

The EQ switch is deleted, and the adjustment control and the bypass switch all deleted. Everything is hard wired to the exact setting that is dead flat. Plus it is feed from it's own vacuum tube regulator just like the 6922 (or 6N5P/6N1P/6N6P) bringing the total of internal voltage regulator tubes to 3. These are SG5B tubes that have leads and are soldered directly into the circuit. In this case all three are directly in series with the plate resistors with no capacitor.

I guess that will make this 6 tubes on the outside and 3 tubes on the inside for a total of 9.


LOOKING BACK

I know when I started this afraid of the thickness associated with these tubes that I wanted a Zen amp style attack with only 3 parts to it doesn't get any thicker.

I learned quickly that the tube has precious little to do with it other than to make it apparent when it's there. Everything is the driver stage. It's 94% of the sound. I made it sound sharp, dull, and every other way possible until I realized that it too can be made to sound like anything you like dependent on the driver stage.

Quickly the design moved towards the Zen Triode transparency and kept the scale tilted towards neutral rather than thickness. Once there, that refreshing sense of air is back and it now gets better with a preamp or higher gain on the inputs without getting thicker.

So now that I have basically installed the ideal preamp inside the amplifier, we have two stages instead of one. That means 2 capacitors instead of 1 and 4 resistors instead of 2. OMG help! No worries, when each stage is feedback free and has this kind of transparency it is like water in a cup.  Dirty water 1/2 inch deep in a cup will not obscure the bottom. Another 1/2 inch  layer of water (2nd stage or component) begins to blur the bottom of the cup. The more you add the worse it gets. Clear water on the other hand can be added to reach the top of the cup without obscuring the bottom. And this is what has resulted. Everything just got WAY better on every level. Just proves no matter how good your source is, it could have been better.  

Right now I have the HOLO audio May dac directly connected to the amplifier, and it sounds like it did last night when I tested the ZROCK2 with it, but twice as clean. All the extra crap gone, no connectors, pots, switches, cables, cords and so on... the sound is so clean and round.

Frankly this seems like the deal of the century to me right now. Simple RCA inputs, your favorite source and 93-96dB speakers if you're triggered by soft hum, 100dB if your not.

Just to be clear, if you don't like to tube roll, want the best, want to get it done with a single component you will have the sound of a ZROCK2 with anniversary mods feeding a CSP325 and the fully anniversary modded SE84UFO series amplifiers but with 4 watts instead of 2 and with 3 times less distortion at 2 watts and up to 8 watts at 10% distortion not to mention seldom if ever having to replace the output tubes since they are likely to outlast many of us.

So it was a long two days but raining the whole time, so time well spent.  I will so put my name on this -- a 100% original circuit that sets a new benchmark.  I think the Audio Gods even raised an eyebrow on this one.






Steve

In response to several comments in this thread regarding 300B amps in general, and the $1,500 price tag on Western Electric 300B tubes, here’s my personal experience.  

I have owned a Cary CAD-300SEI Mk6 for nearly one year now, and up until two weeks ago it had seen only the two stock Gold Lion 300B’s and the three stock JJ Electronic 6SN7’s.  This Cary has never sounded lush, warm, slow, sluggish, or rolled off at either frequency extreme. Instead, it sounds super fast, big, airy, natural, liquid, transparent, and very musical.  Close to thirty years ago, Robert Harley, who had always been seriously opposed to low power SET amps, agreed to review the Mk1 version of the 300SEI.  Here’s part of his conclusion……….

“The 300SEI excelled in the most important areas: harmonic rightness, total lack of grain, astonishing transparency, lifelike soundstaging, and a palpability that made the instruments and voices seem to exist in the listening room.”  He also described it as having “astonishing liquidity.”

All of what Harley said is true…….especially the “astonishing transparency” comment.  But, he also commented that the amp was a bit rolled off at the frequency extremes and that it was somewhat slow.  Unfortunately, the various speakers he used in his review were totally inappropriate for use with a low power SET amplifier.  Had he used a Lowther horn system, an Altec VOTT system, Klipschorns, etc., all of which were readily available thirty years ago, there is no way he would have described the amplifier as somewhat slow.   300B amps are not inherently slow, lush, rolled off, and sluggish.  As we all know, system synergy is everything.

So, was the first version 300SEI really slow and rolled off?  Don’t know—never heard one, but I know for certain that the Mk6 version in my system is not slow or rolled off.  And relative to all other amps I have used in my main system over 40 plus years, including New York Audio Labs, Audio Research, Carver, Cary Audio (2A3 mono blocks), Eastern Electric, Vacuum Tube Logic, Aronov, and Decware (Super Zen 84 and Torii Jr), the Cary 300SEI is, by a huge margin, my favorite amp of all time. And here’s the kicker; if DC heating of the 300B filaments—which the Cary does—sucks the life out of the music, Steve’s amp is going to be nothing short of spectacular……maybe even supernatural! 

Final thoughts this evening……  Are the WE300B tubes worth the initial $1,500 outlay?  Steve’s quick cost/value analysis of the Western Electric 300B is right on the mark.  They’re actually a tremendous value.  With my WE300B’s close to the 100 hour burn-in mark, I can say without any doubt or hesitation that rolling to this $1,500 pair of tubes is worth every penny.  The music coming from my system now is glorious and beautiful beyond description.  I will never go back to KR, Sophia Electric, Gold Lion, Electro Harmonia, or any other 300B, because the Western Electrics trounce them all in every way.  Add to this a 40 year life expectancy, and you’ve got the best value vacuum tube ever made!

Nice write up. I'm curious to hear what sonic differences, good or bad, might be observed when running a csp325 in front of the new amp.

My guess is that the CPS325 leveled against the HOLO Audio MAY feeding a ZBIT feeding the amp is that with a lesser source and absence of a ZBIT the CSP325 will greatly improve the sound.

Steve

Excelsior!

Steve's salesmanship is set on high and really tempting many of us I suppose.

I sit here listening to my wonderful system and saying to myself "I don't need more." I'd have to sell my amps and ZROCK2 and preamp just to get close to affording this amp and those tubes and I shudder at the thought! Possible in the future. . . and then the long wait. . . There's a sort of torment associated with being deeply into audio!

I am so glad that Steve has been able to create this space for himself to explore and discover these new audio territories.

A great preamp is an advantage in any system, esp. it you listen to records.

A CSP325, like the ZTPRE, can not be detected in the signal from a transparency perspective.  It will just make your source sound better and give you more adjustability and voicing control.

That was actually quite helpful. Thanks for the illustration, Steve! Man, I can't wait to see this beauty in its final form. Have you blown the minds of any Decware family (employees) yet, or have the audio gods guided you to keep it to yourself for now?

Nice info on the development of the amp Steve!  [smiley=icqlite20.png]

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No, the cascading label used in reference to gain stages seems to relate to guitar amp overdrive and distortion.  This approach is just what I find sounds good.


Both the ZP3 and the CSP3 have a fair amount of this gain structuring as part of the design.  On the CSP3 some of it is adjustable.  

Decware has always approached gain structures with a different take, in so much as we prefer to 1) always have an input level control (gain control) on every amplifier and 2) keep our amplifiers input sensitivity between 1 and 2 volts.  We do this because it sounds better.  Industry standard is 1 volt and less, or so it would seem, and that is with amps that are typically 100's of watts.  In main stream hifi you have a 2 volt source and a high power amplifier setting there turned up to full blast and a preamp that is used only to turn the signal down to a fraction of a volt so the amp won't get too loud and blow up your speakers.  This only sounds good when it's is cranked up loud.  The rest of the time it sounds lean, dry, flat, boring, tedious.

For me passive listening can more telling of what is right or wrong with the music because you are not distracted by the sound stage or imaging or stark reality of standing there in front of it. Of course in an untreated room where people live this may not hold true. When I listen passively it is 90% reflected energy which is to say I am listening to the room not the speakers. If the room sounded like crap or had its own coloration I wouldn't be able to hear anything through that...

Steve

I almost never listen "passively" no matter where I am in the room or house. That said I too find listening mainly to the room reflected sound over direct sound, is more clearly telling of balance issues. Lots of times I can get tuning to sound great in "seat," or anywhere in the rest of the listening room area. But in the room, with the big and complete sound, for me there is some relatively notable tuning flexibility, many subtle balance shifts that can  sound really good in the room, not being "right" on final examination.

My final and most telling test is listening from my hot bath 20+ ft down the hall from the speaker back plain, in the opposite direction the speakers are facing, and the speaker backs having a wall between them and the hall... So it is pretty much all reflected room sound. From the tub, the sound is not as visceral as in the room, but beautiful and complete when right, and totally revealing all subtle imbalances... Maybe spectral balance is weighted a touch toward bass, making the mids a little too warm and thick, hiding some of the finest detail and space... Or the mids could be a touch hard/focussed... Or just listening to harmonics and decays, the space and harmonics might be more mid or bass oriented rather than even from bass to highest highs.

In my room there is just more tolerance for these and other imbalances, but if the music does not sound totally right and engaging from the tub...easy to diagnose from the there... when I fix the issues in the room, it sounds better there also, and always works best across more recording balances.

Question: if someone already owned a ZROCK2 and ran it with the 300B, would the results be disastrous? Would the redundant implementation allow the user to tailor the frequency response as they normally would, or would this doubling be futile?

Thanks, Lon. In the past months, I've been perusing many hifi forums, and at least 5 times, I've read a thoughtful, informed response to someone's question, only to find that the user name is yours! And not on Decware forums, Audiokarma, and various others. You're all over the online hi-fi world, my friend!

Lon, Sorry for your loss.   It's a strange feeling to loose a father.   : (.  

At least you still have us : ).

Steve

Lon being a caretaker for a father in his final days is a special, loving and selfless duty. May you father rest in peace. Your a good son and man.  Condolences to you and your family.

Joseph