Patient: Ampeg SVT-II, '86 or so. Symptoms: - Distortion - Loss of lows - A weird hum not related to shielding/grounding/etc. (oscillation?) - The freakin' power and EQ lights stay on even when I unplug it from the wall. Is a filter cap going bad and discharging even when it shouldn't? Tube failing (they're about due)? Other? Your thoughts?