Iain M Churches wrote:

"Eiron" wrote in message
...

How strict are the negative feedback rules?

It has to be single ended with no NFB as far as I recall.

I presume a Darlington pair or triple is allowed but if I use a triplet
of NPN/PNP/NPN or even an NPN/PNP pair then someone is going to argue
that it has a load of negative feedback even though it behaves like a
high gain transistor in emitter-follower mode.

The SET uses two halves of a 6SN7 and then a 300B, so three stages
per channel.

Andre's design called for a triode driver tube with a gain of about 40,
so that only one triode drive tube is needed between the CD player,
gain control and 300B.



There should be some design parameters set before I raid my junk box.
To make it fair for the valvies, perhaps I should only use germanium
transistors. :-)

Most people seem to think that the SS design is a lot more difficult
than it may at first appear. It will be interesting to see what you come
up with.

Its easy with a mosfet and j-fet driver, with a low impedance
16 Ohm : 6 ohm OPT.

Its very difficult with BJTs.

Patrick Turner.



Iain