ASI (Amp Scene Investigation) case #56 the “Fender Pro Reverb Filter Cap Caper”. These old bulging dried out filter capacitors were literally robbing tone from this Fender Pro Reverb Amp. They steal dynamic response, muck up the overall clarity and contribute to a saggy bottom end. By replacing them with fresh new capacitors dynamics are restored, the bottom end becomes clean & tight and the amp regains it’s musical, singing quality, not to mention the reliability increases dramatically. If your amp is 10 years or older and never had a cap job do it some justice and have those old filter capacitors changed. Every single time I replace filter capacitors in an older amp it’s like unlocking tone that’s been in prison.