"Stewart Pinkerton" wrote in message
...
On Tue, 14 Dec 2004 11:25:59 +0200, "Iain M Churches"
wrote:

An initial investigation of my 50W amplifier which has the first and
second
stages DC coupled, shows -3 degrees at 10Hz, and -8 degrees at 50kHz.
So about the same as the Audiolab 8000P, and very close to the Spectral?
Not too shabby:-))

That's very impressive for a valve amp.

From the figs you gave me, it looks to be impressive for any amp.
It's a home brew too:-))
There are probably many valve amps out there that match these figs.

This amp has custom-designed Sowter transformers. A similar amp with
Hammond iron may not perform so well.

Impressive results explained! :-)
Well, yes and no. I have always believed that the most critical component
in a valve amplifier is the OP transformer. So many people splash out on a
stainless-steel laser-cut chassis, and skimp on the transformers:-(

But using a Sowter transformer does not transform a poor amplifier into a
good one, it just forms a very important high-quality last link in the
chain.


Iain