24-04-2012, 05:52 PM
Sorry Al, I should have posted an amended diagram. T3, T4 and T5 are now silicon. I haven't got any germaniums and part of my reason for doing this has been to find out how (if?) this circuit can be made to operate with the easier to come by silicon variety. I'll certainly change the capacitor you suggest next.
I tried Alan's idea with mixed results. A cap between the collector and emiter of T4 and/or T5 sent it utterly Deolali but one across T3 seemed to help. I could set the quiescent to the correct 4mA and the traces are better:-
1kc/s at low volume
Turned up to about a quarter
Absolute low
and turned up
It's a long way short of right but is getting there.
- Joe
I tried Alan's idea with mixed results. A cap between the collector and emiter of T4 and/or T5 sent it utterly Deolali but one across T3 seemed to help. I could set the quiescent to the correct 4mA and the traces are better:-
1kc/s at low volume
Turned up to about a quarter
Absolute low
and turned up
It's a long way short of right but is getting there.
- Joe
