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I've been reading through these forums for a long time (a good number of years prior to registering) and I only occasionally see someone that adamant about toeing the ultra-purist line. If we take the 'reducing distortion at all costs' dictum to it's logical extent none of us would be here, since in comparison of roughly similar quality amplifiers tube amps nearly always have more distortion than SS amps.

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A) It's one circuit, not 'circuits'.  B) It's not adding a circuit, it is relocating the L/R conversion transformers from inside the amplifier to in front of the inputs.

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I'm not sure where you're getting the "2 sets being RCA" from. The chain would be DAC - XLR - ZBIT - RCA  - amp input. The one set of RCA cables is the only thing added vs. direct XLR connection. It's not overly difficult to find a 1' shielded RCA cable if one looks. Even a 1 meter well made shielded cable should not introduce any perceptible noise (or it might, if you live close to a transmitting tower).

Aside all that, many ZBIT owners enjoy having and making use of the adjustable output, as it provides extra gain configuration ability. That functionality is not obtainable when the transformers are inside the amplifier.

As for understanding why one would use a  ZROCK, you might find better answers if you pose that question in the ZROCK2 subforum:

https://www.decware.com/cgi-bin/yabb22/YaBB.pl?board=zrock

UPDATE JUN 3, 2022

Still listening to the 20 watt max Diatone drivers in the DNA2 horn cabinets with this amp and I just don't want to unhook it. It's so complete.





You can see where they are placed... so wide and with so much crap next to them.  None of this should work.  But, as I have witnessed a million times in my room, when things get in the zone, it doesn't matter how much crap is in the way -- it just melts and the music manifests as if all that crap literally wasn't there. This week, this combination... has been an example of just that.

I'll have some fun with a video or two soon but sadly it will in no way capture this illusion accurately. I presently have 4 pair of speakers in an arc in front of me and you can't tell which speakers are playing at a distance of only 6 to 7 feet. They all have the same soundstage, which is the width of the room, despite the large discrepancy in placement. Is it the amp? Tonight it is clearly a synergy between the amp and the voice setting and the speakers. Just like last week. I just don't want to unhook it and try anything else. You all know what is in this room, so for me to say that...

I now see why Diatone 610 drivers are bringing upwards of a grand a pair from Japan. If I were going to build a console stereo like the 1961 Zenith stereo unit made the year I was born, I would put this 300B amp in it and two of these Diatone speakers in it. I'm serious. It would be a serious contender for face melting. That's what I would call it... The face melter.

I really love this hobby, as we all do...  every time I hear something wonderful like this, it feels like flying for the very first time which is not unlike the feeling of hearing an utterly lucid 3D soundstage for the first time where it is so present in space that you can hear all the way around each instrument which is what makes perfect reproduction transition into sounding real.

This combination, the speakers in particular, are small like the Caintuck Audio baffles and have a similar unbelievable image specificity and sound stage size.  Something you would expect from Giant speakers in a large space.

So I will continue to enjoy it over the weekend as this amp and the WE300B tubes continue to break in. I am very happy with the sound of this amplifier at the 4 watt output I designed it for. The ability to grow to 8 watts with higher distortion is also nice because it means that at 4 watts there is a sort of RMS headroom for sustained notes. Don't mistake that for the instantaneous peak power of of tubes which is very high. This just drives that number higher making the 4 watts a little more substantial.

I've officially changed my order from the MKV to the 300. I'm aboard and ready to roll on the Decware SET train! I'm quite thrilled with the whole prospect.

I've always been interested in mesh-plate rectifiers but haven't been able to determine if there are any compatible for the Decware amps. Interesting.

The development and seasoning of the 300B Sarah is fascinating to read of. I'm glad I'm on the list.

Thanks GS. I'll look into it. I keep returning to the Sophia Electric Aqua 274B and this one might beat it. May take a while to afford a pair.

thats a beautiful amp ! Ive never lived with a 300b amp but it has always been on my radar. I was eye balling a very popular 300b amp before I bought my Decware but things like plastic molex connectors connecting the transformers , pcb mounted power/driver tube sockets , pcb mounted rca jacks etc  basically everything my audio journey has taught me to try and avoid kept me from pulling the trigger even though Im sure its a fine sounding amplifier. Point to point is in a way a form of life insurance to me.

Steve, I gather all of this research you have done is based around the WE 300b tube.  Have you tried the setup using a less-expensive 300b tube?  How drastic is the change in sound?  

Dr3wman, I read that, too.

However, I have not read where he has actually used the other tubes in an actual test for comparison purposes using the current version of the amp.  From what I can tell all of his reports are based on using the WE 300b which apparently is out of this world.

@Doug

weak area (cost saving) in design and construction is probably a better way to put it I suppose but the Elekit amplifiers use plastic molex connecters to connect those beautiful transformers to the circuit board and the tube sockets and rca jacks are mounted directly to pcb not the chasis, all potential problem areas. It is a kit built amp keep in mind.

in my hands on real world experience I have seen burn/heat marks on pcb's with tube mounted sockets as well as stressed/broken solder points from insertion and removal of tubes both power and driver. I have also tried to fix more then a few times broken rca jack solder points even cracked circuit boards.... case in point , Against my better judgement I bought the smaller Elekit 8200 used (for a friend lol) and it played fine for 2 days until I tried the 2nd set of input jacks and swapped out driver tubes and guess what failed?? rca jacks and driver tube sockets solder points. Can it be fixed?? of course it can. Does the amp sound good?? yes it did, very good in fact.
But cracking open a amplifier and seeing everything soldered point to point and all jacks and tube sockets chasis mounted is a beautiful sight and comfortable feeling singing a song of longevity and as Steve mentioned it results in improved sound quality as well as the control of sound quality. No ribbon cables or thin pcb traces to fight with in the pursuit of perfection.

My mentor was a guitar amp guru who designed his own after 30 years of repairing guitar amps and stereo equipment. He is where I learned to hate circuit boards with heat producing tubes and just in general. He worked in a music store as the head tech. Believe it or not, his job was to take every new amp that came in the store completely apart and hand solder the wave soldered circuit boards and then put them back together and test them before they could go out on the floor.  

Circuit boards... They don't ship well. Vibration causes issues with solder and connectors. They don't appreciate current. They don't appreciate heat.
Wave soldering sucks. There is video on Youtube of a Fender Champ tube guitar amplifier being made from start to finish in 11 minutes.

Steve : )

click to enlarge

It makes me want to change the AC heater frequency from 50/60Hz to 432Hz...  You'll have to click on it and view it full res to see what I mean.  

Is there anything cooler than a vacuum tube? The only equal I can think of is the V8 engine.

GZ34 Metal Base is one of my favorite two rectifiers (overall my favorite - depends a bit on the choice of input tube) in the UFO25, the other or second favorite being the Shuguang GZ480. That might look cool in the new 300B amp (and it seems to add treble extension and clarity wherever it fits), but these are both NOS, difficult to find and expensive. The Psvane ACME looks nice, but it's nowhere close in sound quality in any amp (or for that matter Lampizator DAC) we've rolled it in. If it were a matter of picking the prettiest, my pick there would be the Emission Labs 5U4G Mesh Plate - although the looks depend on correct (sideways) orientation.

Greetings from Switzerland, David.

UPDATE JUN 11, 2022

(Holy crap! Is it really 2022?)

Tonight my mission is to roll rectifiers and see what the results are... how much will it change the sound.

I knew it going in, but despite knowing, was in denial and only expected subtle differences. I was mainly focused on the bass hit and how deep and tight it was.

I think I'm almost embarrassed to admit that I have been somewhat shocked at what I have just heard happen to my amplifier... and it took things so far beyond bass performance that it was like listening to different circuits.

Take away: It's so fundamental. It's like the cone. You go to the ice cream shop and you get either a regular cone or a waffle cone. They are different. You can't imagine one into the other in the middle of your ice cream experience.

Perhaps a bit abstract, so let's just get to the nuts and bolts of it.  Each rectifier tube I tried tonight was no different than bringing a different amplifier into the room.

This is serious shit.  It's always been this way but you just don't get used to it especially when you make or sell the amplifiers. You instantly realize that depending on what tubes are in the amp at the time of audition will determine what flavor the ice cream is, or what kind of cone it's in and we all know that everyone likes one kind or the other so God forbid what if we pick the wrong cone... and don't have the other kind available?

See with busy solid state receivers you don't have this problem. It's so dumbed down that it's just an ice cream cone. Period. There is no distinction between the regular cone or the waffle cone, or even the flavor of the ice cream. In fact it's more like an ice cream flavored cracker.

Highly exaggerated on the one hand and soberingly accurate on the other depending on the price of your SS amp(s).

Sorry, just having a little fun to make a point that the transparency of these amplifiers are so far beyond any of the supporting components shy of a top tear all triode analog rig with passive RIAA... that when given a room to unmask in, things like tonights innocent experiment with a half a dozen rectifiers would have become more a discussion of "did you hear anything?"

I am just floored at the difference in sound between each of the rectifiers I tried, and this is why we try them. Trying to find something in current production that makes the amplifiers sound like they do from a hand picked stash of NOS tubes.

I think the way the evening might should go is like this... PSVANE 5AR4 for the first several hours while you get all of your audiophile needs satisfied.  It's perfection redefined. It's how we want the amplifier to sound. The resolution and speed is glorious -- but -- then after a break and a scotch or a tea you should come back and put in the ACME 274 which would be like putting on soft slippers. The evening could then shift from how perfect everything sounds to how lucid a 3D sound stage can get. The softness is surreal and deep. It sucks you in and it's like boating on the lake without hitting any white caps. Serene and perplexingly there-there. You can reach out and touch it. It's more real that you, because you can get out of the listening chair and it doesn't shift around. It stays in the same 3D space and your perspective on it changes as you walk around in the room. When this level of imaging dominance happens it no longer matters if your speakers are perfectly positioned or even if there are dozens of things the space that perhaps shouldn't be.  It just makes everything disappear without any of the fuss or science.

With the 300B being a directly heated tube and with me running it with old school AC filaments using a directly heated rectifier such as the 5U4 or 274B brings the output tubes to full on almost instantly. They are fully on long before the input tubes come to life so as the input tubes come to life, there is depending on the tubes often tiny muted pops or crackles, perhaps two or three during that warm up cycle.  

With a normal Zen Triode Amplifier using a triode wired pentode the tube is indirectly heated and therefor soft starts around the same speed as the input tubes which are also indirectly heated.  So you can see the difference.  This is why it is ideal to use 5AR4 in this amplifier.  The output tubes will not come on until much later in the warm up cycle and the meters will show this as you watch them waiting for them to jump to 60 or 70 mA. The result being whatever subtle pops or clicks on start up will be reduced or entirely eliminated.

If I were using circuit boards I could create a delayed high voltage circuit using a relay or large transistor to switch on the B+ well after the input stage has come to life.  I could actually create it with obsolete tubes all point to point as well but now we need a larger chassis and more money... But it would be a lot easier to just use circuit boards.  And if I'm going to use a transistor to switch the B+ on or off then I may as well hang some more on there to regulate the voltage against the dynamic current draws of the amplifier.  If I'm doing that I may as well put constant current sources on the cathodes of the driver tubes with more transistors.  Add a few ribbon cables and plastic connectors, the capacitance of the traces on the board and the artifacts of all the transistors that are "just helping out" and you have a modern day sharp grainy less refined artificially dynamic 2 dimensional mess. And it would just be a waiting game to see how long it took to break or malfunction.
Whoops, did I say that out loud?      

This amplifier is turning out to be a real joy to experience and live with over time. So responsive to tubes and and generally hard to make sound bad.

It is has given me some pause to realize that the tube is genuinely unique in the world of hi-fi because it well pre-dates hi-fi. It was designed for human voice. Rolled off on both ends and somehow slow and fast and the same time to keep the tone and textures in tact no mater the distortion content of the transmission. I can pretend to be a fly on the wall during it's development and watching them find those windows of ideals for the application and get a tube that was forgiving and generiously revealing of tone so that the people on the other end of the phone thousands of miles and hundreds of tubes away could recognize the caller. If we used video tubes that had the resolution to pick up a nat fart on Mars coast to coast calls would have been largely noise with some resemblance of a voice in the background unless the caller was next door.

It is an impressive tube for what it is and I honestly look forward to hearing the Decware family report on it's sound as these begin to ship. It is definitely an amp that I could live with as my only amplifier. Especially if I was trying to epitomize the experience of tube sound. Haha, I almost have to laugh as I listen to it tonight on a wide variety of music at how far away this sound is compared to an audio video receiver...  

Music really does sound more real. It has more hit. More weight. You don't have to turn it up. It's Class A1. It delivers nearly 100% usable power. It has tone, and is dynamically more organic and representative of real life than any transistor ever made. Even Mosfet's. Exception might be some of Nelson Pass's rare jewels that he collects and turns into audio art. But most of the busy feedback laden crap out there doesn't play in this world.

The truth is this is what people who want to experience the tube sound are looking for and it is the exact opposite of solid state in that is has 5 times the density and does not have to be turned up to smash your face. It has depth, air and space. It is not flat. it is the opposite of flat.

So in the end I feel that with the 5AR4 rectifier and 6N5P driver tubes and the NOS 12AU7 of your choice you can use the voice switch not to mention the output impedance switch to make this amp sound exactly the way you want it to within the Decware window of experimentation.  No matter what you do you can't change the sound enough to make it sound like not a Decware amp.

I am listening to it tonight on the 88dB house speakers.  It has to be turned up to 3/4 witch is as loud it can go without high distortion.  So right at 4 watts and the listening level in my room is just perfect. I wouldn't want it louder.  Bass is crushing when needed.

I know this is not the target speaker for this amplifier, but for those who just want to seriously listen, an 88Db hifi speaker with a crossover is not going to be an issue for this amplifier.  It does not require an "easy to drive impedance" so it will drive most speakers just fine to a modest listening volume.  

Hi David.

Sounds good. I’ll take you up on your offer to try one. Can I PM you with my shipping address?

Thank you!

Geno

I know the look of those receipts.

That’s from Andy at Vintage Tube Services.

Great tube stock if you are a patient customer.

Bought a lot of tubes from him including the circled one

BicycleJoe, I have sent you a PM back

Yes, the sound is making me continually walk in there.  It is so damn good right now....  If you had let me hear this 20 years ago and told me it was digital I would have laughed in your face.  The dimensionality... it's reminds me of computer monitors when they went from 256 colors to millions so the shadings are nearly infinite.  It helps you hear around the images hanging there in space.  You can tell they are 3D because you can hear around them, they have presence in space.

Besides the insane imaging this is probably going to go down as the most musical amplifier Decware ever made.  I'm still not sure if I like it better than our other amps which tend to me more gone.  But then I feel like I am hearing more information from this amp, so perhaps it is the one that is more gone.  The fact that I can't figure this out is somewhat telling.

Happy listening!

I may have mentioned further up the thread that I did the math on the comparable 300 B tubes available and their prices.

The Western Electric 300 B comes with a five year guarantee, at most all the other tubes come with a 90 day guarantee if any.

So if your average listening is conservatively three hours a day for 5 years 1825 days 1825*1500 = $1.22 per day or 41 cents an hour. But feel free to keep it powered on 24 hours a day since you have a guarantee.

Even though the initial investment has some sticker shock it turns out to be the most reasonably priced bargain in the 300 B class.

So Bicycle J., which pair of 300B's did you buy?

I got the new WEs (two) about 5 weeks ago. So far I've put around 50 hours per week. Yes they sound great but they take a long time to open up.

Looking at the real McCoy Western Electric 300B structure and the WE300B reissue they are very similar while other exotic 300B tubes from other sources have a decidedly different appearance  I can't wait to be in the room with your new amplifier. I went to an audio exhibit  showing in a gallery museum today they used 300 B Amps.

UPDATE JUL 1

Well I've been listening to the amp on both ends of the room.  I used Corner Horns, HDT Silver 8's, ZF15L, ZF15M, the House Speakers, Tube Tots, the soon to be released T6, the DNA with Diatone 610. I still have more to go but I spend a good amount of time with each. My main curiosity during this phase of testing is my preference for the voicing switch setting and how or if it will change.

Initially when everything was new I had a overwhelming preference for one setting because it layered back so much better and then weeks later it changed to other and has so far stayed there despite making a second round with this group of speakers. So it wasn't so much the speakers as I thought, but perhaps the tube breaking in, and the amplifier itself. Now when I A/B the two voices I like them both, not a strong preference for one over the other like when it started.  So between this switch, the output impedance switches and playing with input and driver tubes and the rectifier I have been able to make this amp sound all the ways I want.

There is a sense of ease about this amplifier knowing the output tubes last so long.  Makes me not care about running it 16 hours a day.  In fact if you don't you're going to wait a long time to hear what the WE300B tube actually sounds like.

I will say overall my highly triggered ear for edges, grain, pinching, shout, have been on vacation with this amp because it just doesn't seem to ever do it with decent recordings which is pretty much all I listen to.  Still puzzled as to how it creates this illusion, or does everything else tend to take it too far?  Which way is actually more real?  That's the other part of this testing besides the switch that hope to answer before it's all over.  

This amp would be the holy grail on compression drivers.   On my House Speakers with those amazing tweeters I get captivated by the pin point precision... the highs just sparkle like fireflies in the rain on a warm summer evening and not like sparks off a grinding wheel.

Steve

So great to hear about the amp as it seasons. I'm eager to read how it may sound with HR-1 speakers.

Anyone willing to hazard a guess, as to when the first Sarah will hit the bench?