The output stage is a linear amplifier. One dB difference at the input produces one dB difference out. Maybe this was being used at a volume level where smaller differences are more obvious. I might try it myself, just to see if it helps with the High input volume.crgfrench wrote: ↑Tue 03/02/21 11:25 pmThat difference gets amplified again in the output stage.TriodeLuvr wrote: ↑Sun 02/28/21 12:11 amThe gain of a LTP is typically less than half the gain of the tube in grounded cathode (bypassed) mode. With the Presence control at minimum resistance and no NFB, the Marshall 12AX7 LTP exhibits a voltage gain of approximately 22. Substituting a 12AT7 with no other changes, gain falls to about 16.5. That's a difference of 2.5 dB. I would have thought you'd need to pay close attention to hear that.
Jack