Matched transistors in Threshold SA/_e amplifiers?

[Danish]

This question is for Nelson:

I have a few of the Threshold SA/_e amplifiers (SA/12e and SA/4e), and was wondering if the TO-3 output devices has been matched in any way when these amplifiers were produced? If yes, could you tell me what the matching process and criteria were?

I see no markings on the output devices, so that made me curious.

Thanks,

Michael

 

[Nelson Pass]

They were tested for gain (there was a minimum acceptable
current gain) but not otherwise matched. Matching was
not required for performance, but gain was.

 

[Danish]

Ahh, that makes sense. Thanks Nelson