About tube "matched pairs"

[Panicos K]

I have a rather strange question.If you had two "matched pairs" of tubes,in this case EL84's of the same maker but with two years difference in manufacturing dates,how would you use them?one "matched pair" on each channel,or,one tube of each pair on each channel?I would appreciate any comments.

 

[boywonder]

I have a rather strange question.If you had two "matched pairs" of tubes,in this case EL84's of the same maker but with two years difference in manufacturing dates,how would you use them?one "matched pair" on each channel,or,one tube of each pair on each channel?I would appreciate any comments.

Assuming that you are talking about a push-pull amp, use each matched pair for each channel. That's why they are matched, to share push-pull duties evenly.

 

[Panicos K]

Thanks for your reply.Yes it is a push-pull amp.

 

[Geek]

Manufacturing dates are moot.... tubes are matched for transconductance or DC current at a given grid bias.

One of the best guitar amps I had was matched within 500uA of each other at bias and they were even different brands 🙂

Cheers!