300b lovers

Lynn, I hope you bounce back soon from Covid.  I got Covid in the remote state of South Dakota last year so go figure.  Your meds will  surely alleviate the symptoms.

Pindac, I heard the Jubilees in a local dealer's room and they are truly sublime, really stunning, fit for a way big room.  

I visited with the owner of Whammerdyne Audio who had his 2A3 SET amp driving the stellar Songer speakers.  As far as I can tell, the Whammerdyne designer has a different amp design philosophy than Don and Lynn, who favor a P-P design. Both Don and Lynn loved the sound of the Whammerdyne/Songer room at the Seattle show so that might say that there a lot of paths to get tube amps performing in an excellent fashion. I would have liked to hear those exemplary Songer speakers with Don and Lynn's 300b monos.  Yes I would and I bet Don and Lynn would too. 

I had a couple of flea watt tube amps including an excellent 8wpc Dennis Had amp that just ran out of gas even with my easy-to-drive Spatial Audio speakers.  Don and Lynn's 300b monos have ~27 wpc, which can drive a boatload of speakers.  Their mono's drive both my Spatials and Cube Audio speakers with alacrity, no question, no limitations.  And with dead silence between songs, more so than some of my excellent SS amps.  

Matt Kamna, the designer of the Whammerdyne, is an old Tektronix guy I’ve known since the late Eighties. We were at the second meeting of the Oregon Triode Society, and were both so impressed by what we heard at the meeting we set aside a project on a transistor amp .... for the simple reason it is much easier to get good sound than with transistors. Tubes are simple to work with and sound great, right out of the box.

Back in 1996, when I lived in Portland, Matt physically built the first Amity amp, although it was 100% my design from the ground up, and my first amplifier project. At the time, Matt went down the path of gigantic and extremely rare Western Electric power tubes in the transmitter class, I moved to Washington State, and then to Colorado.

Matt approached me a few years back and wanted me to write the user manual for the Whammerdyne 2A3 amp. He had definitely moved in a new direction. Matt’s an old friend and I didn’t mind some spare change, so yes, I agreed. The Whammerdyne 2A3 has some interesting user setup settings, and I had fun coming up with various names for the internal features of the Whammerdyne. Yes, I know what’s inside, in order to write the fairly complex user manual. (NDA’s were signed, etc.)

Internally, the Whammerdyne 2A3 couldn’t be more different than the Amity, Karna, Raven, and Blackbird (which are all closely related). Matt’s design is almost the anti-Blackbird, but what can I say, it works really well. I know from personal experience these things don’t design themselves. They look simple, but I can tell you, they are tricky to get right.

It was delightful to hear the latest Whammerdyne at the 2023 PAF. It physically looks more or less like the original, but sounds much more refined and elegant. It’s clear they’ve been working on it, and good for them for doing it. And it works really well with the Songer Audio speaker, another Portland company.

It’s interesting the SET folks are all-in on the single-ended concept, and have been since the early days of Sound Practices magazine. I certainly fell in love with direct-heated tubes, but felt from the beginning that the colorations of push-pull amps (compared to SETs) could be solved with a little creative thinking, and a return to the well of Western Electric research. I credit Vacuum Tube Valley and John Atwood for pointing me in the right direction.

Since I’m on a roll (and thankfully nearly out of the woods on Covid), let’s talk about PP coloration. It exists, it is real, and if you spend time with top-quality (not junk) SET amps, the absence of that coloration is wonderful and refreshing. Compared to Golden Age amps, everything is so clear, so open, so natural with wonderful tone colors. (Again, you never hear this with junk SET amps, which are murky and dark.)

The magazine conventional wisdom would tell you that clarity and beauty is "euphonic coloration". That’s complete horse****. Euphonic colorations can’t add detail, resolution, more depth, and more in-the-room presence ... colorations can twiddle with subjective tonal balance, and usually adds mush, murk, or grain. They don’t remove it. Build your own amps and you find this out right away (I can see Don nodding his head). The magazines have had this wrong for forty years.

Back to PP coloration. The mainstream "alternative" view is that it is inherent to to all PP, so just build SET and forget about it. Entirely aside from power considerations, SET has its own universe of colorations unique to SET, and they can be quite severe. What I call "junk" SETs sound like old antique equipment. So designing a really good SET isn’t quite as simple as it appears at first glance. At the top of the performance spectrum, it gets fiendishly difficult, with costs and complexity reaching into the stratosphere, and all charm and simplicity lost.

I’m in the small minority that feels the colorations of PP are very real and not imaginary, but can be solved. The Golden Age amps of the Fifties and Sixties, and the modern copies from the big name vendors, all have remarkably similar circuits, boiling down to three types (Williamson, Mullard, and Dynaco, with a handful of variants). These were adopted because they were well understood, responded well to feedback, and were cost effective at the time. Even Marantz and McIntosh were part of the watts-per-dollar race, which only ended when the Crown DC300 and Phase Linear 700 came on the market, putting all tube amps in the shade. From then on, if you wanted Big Watts, you got a transistor amp. Still true today.

But Golden Age is not the only way to build a tube amp. There were other, pre-war circuits, before the Williamson wiped out everything in 1948. The pre-war "floating paraphase" phase inverter ... not as perfectly balanced as later circuits, but more powerful. Transformer coupling, which passively inverts phase, but demands ultra-performance transformers, and also rules out global feedback. And other methods.

The prewar era had a lot of interesting byways and interesting circuits, which all disappeared by the 1950’s. And they do sound different, and get away from the 1950’s monoculture which dominates tube audio. The tubes don’t care; they cheerfully work in any circuit, provided you pay attention to operating point, loading, and stability (part of any amp design).

At any rate, when you stop using Golden Age circuits, the "PP sound" changes. It’s no longer a thick blanket that lays on the sound. It might be a brand-new coloration, or might go away. That’s where the fun starts.

@lynn_olson Another nice to read recollection of a History of Amp Design and the connections made over the years 'pardon the pun'.

Some of the content once more Jogs my Memory.

I recollect my 845 Power Amp designer/Builder, requesting that I keep him in the loop if any EE support is required during ownership.

Again as a recollection, it was made known there was their own Hooks in the Circuit Design, that was beneficial to creating the perception the sound produced was transparent.

I am now wondering if this was a similar description to your own, where creative thinking has been used to produce circuits with the potential to align the SET - P-P sonic where there is seemingly a mimic, rather than a contrast.

I am due to spend time with the EE, in the not too distant future, My Balanced Pre-Amp will soon be complete. Which will then be passed onto the EE, who is to work on the 845 mono's, whare a Balanced Design is to be produced, with the Single Ended option retained.

I have been a friend and loyal to this EE's Services for more than 30 Years, I think that has proved sufficient as a 'NDA' about his early works. 

As an aside, a few individuals have asked to see inside the Power Amp. One  individual wanting to make a mark in the audio world, who I knew quite well, and have not at present not communicated with for quite some time, attempted on more that one occasion to be allowed to take the Power Amps Base off and see the Circuit.

My not being supportive, at one time lead to my being threatened that I was on my own with any future EE concerns, if l did not accommodate the request. For other reasons relating to this individual, I am on my own 'Hey Ho'. I'm pleased I 'stuck to my guns' and honoured the Designer /Builders request , and I certainly am not on my own where EE support is needed.

Lets hope owners of your New Amp design, do not find themselves meeting Pirates scheming to steal another's IP.       

@pindac 

There are only a few things one can do to keep someone from pirating a design.   Point to point wiring and manufacture avoids circuit boards.  When someone sends a PCB design for manufacturing, there have been cases when designs have been stolen.  That said, there is little that can be done to eliminate someone tracing out the circuit.  I used to restore vintage tube gear years ago and one major American manufacturer would actually use regulator and other chips whose labels had been erased so you couldn't tell what part they used.  They guarded the schematics of course, so you simply could not repair their gear unless the problem was obvious.  

One just has to hope that owners are honest.  I have never had a problem with the issue.  I suppose should this design become wildly successful, someone may wish to steal it.  The power supply is non-standard and would be a little more difficult to copy, but the possibility exists.  So be it.