If you think you can write a more compelling argument than I can about
the evils of excessive NFB, have at it. But every time I see you, like
the other techies you merely kibbitz what better men have written.

I am now doing 845 amps, two per channel for 50 watts each.
I expect music to be real fine. Damping factor good, noise low,
bandwidth wide, distortions negligible and maybe I can add 6db of global NFB but
I doubt any difference due to some **added** NFB will be heard.

You probably won't need the NFB. The biggest problem with 845 is not
deciding how much NFB to use but steeling yourself to let them out of
the door. 845 are God's own tube. I really hesitated when I needed the
space, wondering if I shouldn't keep the simple SET 845 rather than my
Millennium's End SV572-xx amps.

And I am using KR845.....

I think I'll use sepaarate cathode biasing for each 845, tubes and a trioded EL34
driving a 1:1
IST but with a cap shunting the anode to secondary winding to make sure the
HF transfer is near perfect without the leakage inductance having any effect.
Input will be 6SN7, but maybe could be 6SL7 µ follower



Trev has never done anything like this and simply doesn't understand.

It's not so difficult to open your mind to new experiences and new
ideas. But first one has to stop being a smartarse, and that I don't
think poor old Trevor can manage.

He regards SET amplification as a form of hi-fi illegitimacy.
Calling people *******s for owning and preferring SE amps to his fav brands of solid
state
makes him look a fool.



With 845, just no need for the 106dB of added NFB used in SS amps.
I don't care a bit about what Trev says.

I'm fast reaching the same conclusion.

Patrick Turner.

Andre Jute

A colleague in Sydney is doing an SE amp with 6 x GM70 for 120 watts.
But it will be switchable to PP......its doable, 5 very good switches are needed, and I
did the OPT design.

Whether the GM70 is better than 845 is unknown.

I like challenges. The OPT for 845 has 3 times the turns that my 300 watt PP amps have,
and the wire is thinner for 845, and my eyes are not getting younger....

Patrick Turner,