Nick Gorham wrote:

Ian Bell wrote:
Nick Gorham wrote:


Fleetie wrote:

I am VERY interested in learning about how to design valve amps,
but before I do that, I want one for my hi-fi, that just works.
Then I'll worry about how to design them myself. I guess the
simplest design to start off with is a Single-Ended Triode
amp - would that be right? Only one grid to worry about, and
only one power valve. Might as well walk before one tries to
run!

But for now, I just want a working valve amp for my hi-fi.


Ok,

First up, Single ended anything is simple on paper. BUT. to actually
make it sound as you might wish, its not quite that simple. As SE is
simple everything is important. Its very dependent on the regulation of
the power supply, so either you have a complex regulated supply, or you
use choke regulation, which means big (as possible) chokes, Then the
last cap in the power supply is in parallel with the output transformer,
so you can't just use any old electrolytic and expect good results. Most
SE designes are limited in gain, so feedback is not used


I don't know of anything that inherently means an SE design is gain
limited. The very first one I built back in the 60's used feedback from
the output
transformer. It consisted if a 6J7 and a 6V6.

Ian

Agreed, but what I said was most designs are gain limited, not that they
had to be.


Fair enough provided you can justify that remark. Are you saying that is
just how ?current? SE designs happen to be? If so is there any reason for
this?

Ian