Another preamp question...

[ken3983]

On July 26,2004, I posted a schematic of a preamp.I built it and worked wonderful when it was connected to a power amp.My question was, if I substituted two Darlington transistors in place of the two NPNs already there, would it give more gain or is it kinda redundant.You can do a SEARCH for the word preamp to find the schematic.

-Ken

 

[Nigel Goodwin]

On July 26,2004, I posted a schematic of a preamp.I built it and worked wonderful when it was connected to a power amp.My question was, if I substituted two Darlington transistors in place of the two NPNs already there, would it give more gain or is it kinda redundant.You can do a SEARCH for the word preamp to find the schematic.

Interesting idea!.

It's certainly not something I'd try, but I don't really know what effect it would have?.

The circuit has 100% DC negative feedback, so the DC balance would probably compensate - but there's no AC negative feedback at all.

I suspect it may just become too unstable or too noisey, I certainly wouldn't consider it a practical proposition - even replacing just one of the transistors with a darlington would probably make the circuit unusable.

If you've got a darlington handy, try popping it in, and let us know what happens!.