Those mods mainly boost the gain of the amp before you engage overdrive. Also any mods that involve placing a 47nF (0.047uF) cap across a preamp cathode, will have the side effect of boosting the higher frequencies. And I guess that's not what you're looking for.
If you're finding the amp too strong in the higher frequencies, it would be good to know what kinds of tubes you're using in it, and what kind of speakers. Those two variables make a huge difference to the sound of this amp. FYI KT66s will make the amp sound somewhat darker.
_________________ Great tones come in small glass jars!
|