I finally have my Champ back to fix the crappy sound: John Phillips wrote this a few months back: The amp is biased wrong. That may sound surprising, since it's a cathode-bias amp and from what you're saying is probably totally stock, but it is true. Fender built them like that. (What probably happened was that in about 1965 they raised the internal voltages to get more power - 6W not 4 - but for some reason forgot to alter the value of the cathode resistor. The result is that the 6V6 runs far too hot, which not only shortens its life but makes it clip far too soon at the forward end of the waveform, resulting in low clean headroom and a mushy, farty distortion. I don't know why no-one noticed, but they built them like that for over 15 years...) In order to make it run correctly, you need to replace the 470-ohm cathode resistor with a 1K (preferably 5W wirewound instead of the old 2W carbon), and replace the cathode cap with a 50V-rated type since the bias voltage goes up to around 30V; possibly 50uF not 25 if you want the same bass response. In fact, if they haven't already been done, it may be a good idea to replace all the electrolytic caps in the amp, since they're well over 20 years old now - if it has ply sides it was made no later than the middle 70s (you can date it accurately from the pot and transformer codes usually). It's also a very good idea to fit a screen-resistor, which they left out too - 1K 2W wirewound is ideal. Here's the amp. Please tell me which resistor to change. I can drain the caps if I have to. I would appreciate some help on the date codes too. What is the circuit number of this one? Would the circuit number be found on the amp anywhere? Thanks much. If my interpretation of color code is right this is the only 470 Ohm resistor I can find. Change it to a 1K? Sorry but I had to split the close-ups but I think you can see what you need to see. Let me know if you can't. Here's the rest. This pot says 1377348. Is that the 48th week of 1973? Thank you. Thank you. Thank you.