question about elliot P3a Amp

[ben-horne]

Hello,
I#m new into solid state and try to understand some
easy amp schem's.
So in the 3A there are two caps C4 and C6.
Is it right they are for stabilisation and avoiding oscillation ?
Why there is no "BC-cap" across Q5 ?

Thanks for help.

 

[Twaksak]

Hi ben-horne ,

Is it right they are for stabilisation and avoiding oscillation ?

I think the short answer is yes.
I'll take a stab at attempting to clarify your problem. As for C4, frequencies above P1 are tamed by this capacitor. A local feedback then is created above the P1 frequency. As far as C6 i'm guessing it compensates for internal capacitance difference between PNP and NPN devices that are not perfectly complementary.

I have ordered from Rod and am sure that if you intend to build this amp he will readily answer any questions you may have.

Chris