We have a large supply and can match them for gain. Matching these tubes on a Hickok will not work. Testers measure transconductance, what you need to know in MU which is what we measure. Matching transconductance will not match voltage gain.
We started making EM7 amps 8 years ago, seems others have now discovered this tube. We match them up for our amps all the time. Our circuit is pretty logical
, The high gain tube is set for full gain as it the second section. The overall gain of our amp is about 12 dB and of course varies several dB with the tube.
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