I bought my PS-100 several years ago and its not had any problems until recently. The volume fades in and out constantly. I checked cables,the amp Im running into it and the speaker cab. Everything checks out fine . What else could it be ?
Hello, Welcome to the Fryette Forum! Depending on how much use your PS-100 has had, it could just be the power tubes. This is not an absolute diagnosis but it is a very likely scenario. I recommend that you purchase a new matched matched pair of power tubes and install them.
See the attached video for details. Please let me know if I can assist you in any way. Cheers! Gil
https://www.tubesandmore.com/products/vacuum-tube-6550-jj-electronics