Apparently made by Signetics, marked as follows:

AMP2947
6808

I find no cross for it in my ECG book, can't find a direct reference
on-line. This is the driver transistor for a vintage-1971 AR
integrated amplifier. The outputs are 2N3055s.

Their schematic lists in parenthesis (2N3054) which physically fits,
but gives quite a distorted output. I matched two 2N3054s with very
low leakage and matching Beta, got distortion. I used two "stock"
transistors from another amp, worked just fine. Which, by the way,
closely match on my tester the parameters of the 2N3054s... go
figure.

Thoughts? Ideas?

Thanks in advance.

Peter Wieck
Wyncote, PA