Tube Rolling-Amp vs Pre-amp

[Truth71]

I have a Pemier 17 LS2 and a Classic 120. Wonderful gear!
Both use 6922 tubes.
"Theoretically", repalcing tubes in pre-amp vs amp- which would have the greater effect?

[AnotherJohnson]

I’ve not seen the schematic for either.
But if they’re like typical tube preamp and amp designs, the 6922s are in both devices to provide gain. As a twin triode, you only need one 6922 in many CJ designs. It is capable by itself of the necessary preamp gain in many applications. In the amp, the final gain and load coupling is the job of the output stage. Think of the small tubes as sort of pre-output stage stage.

Assuming all the 6922s are in equally good condition, so that none actually need replacing, I think you’ll notice messing with the preamp 6922s more quickly than messing with the power amp 6922s. But this may be dependent on factors that are system dependent.

You’ll have to report on what you hear.

[AnotherJohnson]

The logic, which may be defied by ears, is that the earlier in the stream that the perturbation is made, the more pronounced the affect of the perturbation will be down stream.

Of course if you actually replace a tube on its way out, or a tube that sounds ok but is out of spec with a properly performing tube, that one may make the biggest difference.