Peoples preferance: Tube amp circuit. Baised (name your type) Or Push-Pull

[matchampion0]

Hello I am starting to build a guitar amp with 2 X 12 " Celestion vintage 30s. I thought I might ask some people hear if they would like to describe their preference for cuircuits powering the tubes(any of the bias types or push-pull).
(I remember covering the different amplification methods in my electronics courses as when i was much younger)
I know some of the advantages and disadvantages of most of the methods but still don't have a strong preference In either direction.

It would be great if I could get some input from people?

to help me decide.

Thank you

[Helmholtz]

All amplifier tubes need a (negative) bias voltage between grid and cathode.
Power stages are either single ended class A (low power) or push-pull class AB/B for higher output power (>10W).

High power (> 15W) PP amps typically employ fixed bias, lower power amps may use cathode bias.
There are a few exceptions. e.g. Vox AC30 utilizing cathode bias class AB for 30W to 35W output.

Above around 35W most amps are fixed bias PP class AB.

There are great sounding examples of all types.

[tdlunsfo]

My preference is lower power, push pull cathode biased amps with a solid state rectifier. I just built a simple 6AS5 PP amp employing these very techniques and it sounds great. This is just me though and there is obviously nothing wrong with other methods.

[Enzo]

I see the problem as one of intent. In the hifi world, all circuits SHOULD have the same goal - flawless and true reproduction of the source material.

But guitar amps are a part of the sound creation, they add their own character. They are not supposed to be hifi. SO a learned technical paper might tell you that such and such phase inverter has lower distortion or is easier to clip or whatever. But who says that is desirable or not? Only you. Your amp needs to please your ears, not anyone else's. And pleasing your ears may not require pleasing all the engineering factors.

Example: no learned paper anywhere concludes that punching holes in your speaker is an improvement. And yet there are songs recorded wherein the guitarist poked a bunch of pencil holes in his speaker cone because he liked the rough sound.

Just my own opinion, but I might suggest rather than trying to decide what to build on technical criteria, you consider finding an amp you like (Fender Bassman or Deluxe, or a 45 watt MArshall for example) and build that, or something similar.

[Chuck H]

I see the problem as one of intent. In the hifi world, all circuits SHOULD have the same goal - flawless and true reproduction of the source material.

But guitar amps are a part of the sound creation, they add their own character. They are not supposed to be hifi. SO a learned technical paper might tell you that such and such phase inverter has lower distortion or is easier to clip or whatever. But who says that is desirable or not? Only you. Your amp needs to please your ears, not anyone else's. And pleasing your ears may not require pleasing all the engineering factors.

Example: no learned paper anywhere concludes that punching holes in your speaker is an improvement. And yet there are songs recorded wherein the guitarist poked a bunch of pencil holes in his speaker cone because he liked the rough sound.

Just my own opinion, but I might suggest rather than trying to decide what to build on technical criteria, you consider finding an amp you like (Fender Bassman or Deluxe, or a 45 watt MArshall for example) and build that, or something similar.

This^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^!!!

[Justin Thomas]

What Enzo & Chuck said (which is what Enzo said). That said, I'll still take the time to share my opinions...

In my limited number of builds (5) I've found my favorites have been EL34- or 6V6-powered. The 2 faves had a pentode up front, a simple Vol/Tone setup, & a Concertina/Cathodyne phase splitter.

One was fixed bias & SS recto, one was cathode biased & tube recto. No preference from a tonal angle, though I luke the "charm" of a tube recto, & I usually choose one that drops quite a bit of voltage for the sake of my power tubes.

But I also love my 67 Bassman & 62 Concert.

Justin

[Mick Bailey]

My own amp preference changes all the time, but it isn't dictated by topology or bias arrangement. A long time ago I judged an amp by the distortion characteristics because I wrote and played a lot of rock songs. I hardly paid any attention to how an amp sounded when played clean. Later I started to play a lot more with a clean or mildly overdriven amp and nowadays I'm looking for an amp that has a good clean sound. I'm lucky in that I get to play through a lot of different amps of widely ranging types, brands and price brackets, but I rarely think about the underlying design; a good amp is a good amp. Now, my opinion of a good amp may not be yours. If I think about the amps I've had recently for repair that I really enjoyed playing through, they're all so different that I wouldn't be able to single out one on the basis of whether it's single-end, push-pull, cathode or fixed bias (or a mixture of bias types).