I've noticed that my amp just doesn't sound great anymore. I measured the voltages inside my amp and I'm getting lower than spec'd voltages. The Marshall JCM 800 2203 Service manual says I should be getting 468VDC B+ with a 120VAC supply voltage. I'm only getting 450VDC B+ at 120VAC. Now, my amp at one time did have the spec'd voltage of 468VDC, but anymore I'm only getting around 450VDC, and my amp doesn't sound anything like it used to. Is this low voltage due to a PT that's going bad? I don't know. That's what I'm asking here. I know there's a lot of great minds here, so I thought I'd put it out there and see what everyone thinks my issue may be. Thanks in advance to everyone that replies.