You will get upgraded values that will improve the performance of your amp. In the old days, people didn't play very loud and most bands didn't even have a PA. When I was a kid I remember seeing local bands where the Unidyne Shure (high impedance) microphone was simply plugged into the Normal channel of their amp.
So the power supplies were not so important when the amps were not drawing a much current. But if you replace the caps using stock values the amp will play out of tune when overdriven. It is especially noticeable in the key of B or B flat. That is because the AC ripple current (120 Hz) that occurs when the amp is overdriven, is a frequency between a B and a B flat. So to keep the amp playing in tune, one must increase the main filter supply to at least 100 uf. To achieve this, when we isimply replace the two 70uf (totem pole stack filter caps) using two 220uf@350 volts instead. The circuit will then "see" 110uf at 700 volts. This will keep your baby playing in tune, even when overdriven.
Also, we recommend increasing the screen supply capacitor to a 40uf. This keeps the screens from "wiggling", resulting in more front-end sting on the note. This helps you to punch through a mix without seeming too loud.
We recommend going to a 100uf@100volt bias cap. This can be used for the negative supply or even as a bypass cap in the case of cathode biased output tubes. Some Fenders used 50uf@50v and the problem was sometimes the voltage in the circuit exceeded the 50 volts. We like to use the 100uf at 100 volt because it doesn't hurt to filter out more hum and that's what a larger value negative bias filter capacitors will do. And having a larger voltage rating just gives us more safety.
You get a total of 45 components, enough to do cap jobs on three Fender type or similar amplifiers. If you would like to upgrade to get the complete overhaul package that includes coupling caps, compensating caps, tone caps we offer that package
HERE.
