Mod, now speaker pops on shutdown

[ronh]

Hi, I am hoping someone can help with a problem. I modded a Vox AC-10C1 amp. The mod was to increase the cathode resistor (R8) from 120 ohms (posted) to 148 ohms. (actual) I wanted to reduce the bias on output tubes. The tubes are running hot, lettering on tubes is gone. Internet says this amp eats tubes. The amp works and sounds better to my ears. Problem is now when I switch the amp off I get a loud pop in the speaker. Didn't have this before mod. Amp has no standby. So, does anyone know whats going on. I can take voltages if needed. Changing the resistor is all that I did. Thanks.

[Helmholtz]

Please post full schematic.

[ronh]

Here is the schematic. Export Pages AC10C1_SManual.pdf

[g1]

Check how balanced the power tubes are now with the different idle current.

[ronh]

I will check all the voltages of both tubes. If there is an imbalance, why would that create the problem? School is in. Thanks