[UntilThen]

This is what happens when layman specify what they want in a tube amp. They drive the designer crazy.

 

[ThanatosVI]

This is what happens when layman specify what they want in a tube amp. They drive the designer crazy.

"Can't I have everything?"

The next guy seeing this will likely ask, can I have an amp like Zachik, but also have it switchable between KT88/EL34 and the 300B?

 

[UntilThen]

"Can't I have everything?"

The next guy seeing this will likely ask, can I have an amp like Zachik, but also have it switchable between KT88/EL34 and the 300B?

I usually only have one important criteria. I want the amp to be very quiet. No noise or hum at all or I won't want it.

It usually comes back very quiet. Zero noise.

 

[ThanatosVI]

I usually only have one important criteria. I want the amp to be very quiet. No noise or hum at all or I won't want it.

It usually comes back very quiet. Zero noise.

Yeah after having experienced a quiet tube amp, there is no going back for me either.

 

[Zachik]

BTW, cool name. Solar Flare, would burn you up (and your pockets) ROFLMAO

Thanks. I got to name it

 

[Zachik]

The next guy seeing this will likely ask, can I have an amp like Zachik, but also have it switchable between KT88/EL34 and the 300B?

I strongly believe that Mischa will never ever EVER agree to build another one just like this... when you read more details in the next few days - you will realize that what I disclosed so far is the tip of the iceberg of insanity!

I usually only have one important criteria. I want the amp to be very quiet. No noise or hum at all or I won't want it.

So far, from everything I tested - this amp is QUIET.
That was one of Mischa's goals, which also led to some late design changes... In fact - that is a good segue to disclose 1 more piece of detail:

Initially, the amp was supposed to be a single-chassis amp. However, due to the insanity inside, or as Mischa described it "game of Tetris to fit all the components inside the chassis" - once Mischa started testing, he was not happy with hum levels. Apparently, it was audible despite layers and layers of isolation around the transformers.
The solution? Transformer exile (to a secondary chassis)
That was a late change to this project, and I was considering naming the PSU chassis "Saint Helena" but did not want to delay the project even more, waiting for the custom front plate...
That change made a BIG difference (according to Mischa). I can testify that so far - the amp is QUIET.
I do plan on testing it with Grados and IEMs, just for the fun of it

More (much more) to come...

 

[UntilThen]

I can testify that so far - the amp is QUIET.

Good to hear. That is the first test.

 

[maxpudding]

This is what happens when layman specify what they want in a tube amp. They drive the designer crazy.

"An architect's dream is an engineer's nightmare."

 

[Xcalibur255]

That last bit about the power LED is a brilliant idea.

 

[UntilThen]

"An architect's dream is an engineer's nightmare."

The architect wanted this and the engineer built it.

 

[UntilThen]

@bcowen wanted this and so it's done.

 

[jonathan c]

@bcowen wanted this and so it's done.

… best of all, it can FLOAT !!!

 

[Zachik]

Today's chapter might be named "Mischa's next strategic mistake"...
After agreeing to 2 topologies (SET / Parafeed) and 2 loads (CCS / Resistor) - Mischa wanted to know which driver tubes do I want to use for driving the 300B power tubes.
"What are my options?" I asked.
So, Mischa told me I could go with 6SN7 (or 2 x 6J5), 2 x 6922, or 2 x 12AU7.
"Why was it a mistake?" you may ask...
I think that would answer your question:

So far, I only tested it with 12AU7 and 6922 drivers. The super busy life of working in a startup........

As implied by the "INPUT" switch - Solar Flare has 2 (RCA) inputs.

What else? hmmm.....
Power tubes! OK, we all know the internet is a fascinating and dangerous place. Case in point: I was searching around to learn more about 300B amps, and came across a couple amps that support both 300B as well as 2A3 tubes. Pinout is the same, but bias and operating points are different. Mischa told me that in order to support both - neither would likely work in its optimal point. Also, Mischa told me 300B tubes can be driven HARD and produce a lot of power (and distortion), or driven gently and produce less power but also less distortion. In fact, according to Mischa, they could sound quite differently depending on how they're driven / biased.
Hmmm........ Challenge or opportunity?
And while we are at it, what other tubes types are pin-compatible? You know... Asking for a friend...
The result:

Say what??? 2A3 tubes and 300B tubes (at 2 different operating points), and 45 tubes??? and 71A as well?
Yes, yes, yes, yes and yes!!!
Each tube type operates at the right bias and operating voltages, so no compromises here.

There is still more to come. I know it is already A LOT, but we are not done yet. More surprises on the front panel AND the back panel to come

 

[OctavianH]

One of the most original amplifiers I ever saw. Incredible. But it has manual fixed bias right? Otherwise you would be able to use 12A*7 and 6922 in the same sockets but with an adapter. Both are noval but bias differently. Right?

 

[Zachik]

One of the most original amplifiers I ever saw. Incredible.

Thanks!

But it has manual fixed bias right? Otherwise you would be able to use 12A*7 and 6922 in the same sockets but with an adapter. Both are noval but bias differently. Right?

I will let Mischa answer this one... Just to make sure I am not providing a wrong answer here.