So, after repairing and converting an old Stromberg Carlson Signet 22 EL84 PA amplifier, I noticed a terrible sounding distortion when is turned up loud, and the tone control is set to cut no treble. I tested this on several speakers to make sure they weren't the culprit. The amp has all new tubes, a JJ 12ax7, JJ EL84s, and a NOS Raytheon 6u8. The EL84s are biased around 80% dissipation. I would go lower, but I'll have to get a higher value resistor. Originally it was biased at absolute max... I let the two preamp tubes have more voltage by lowering the 33k resistor that goes to the filter cap. I did this to increase headroom a bit. All voltages are still well within a safe level. This is not my first experience with tube based electronics, but I've never repaired a guitar amp. I was wondering is crossover distortion is what is occurring. I have a sound sample of me hitting a few chords Thank you!