I was playing the my new/old super reverb the other night and it started cutting in and out distorting really badly. Seems like something vibration or signal induced, but it's hard to tell for sure. Swapped the tube in V2 around a few times as well as the phase inverter but neither made a difference. It's only in the vibrato channel, so it has to be something in that circuit. I took it back to my boy Casey Gooby again to see what's going on.
We decided it could stand to have the power supply filter caps changed, so I ordered up a some big 'ol blue Sprauge Atom Electrolytics. We also decided the mystery 4ohm output transformer wasn't doing me any favors, so we ordered up a new Mercury Magnetics that is spec'd as an upgrade for a '59 Bassman. What's cool about it is that it has 2ohm and 4ohm taps, so I can run it @ 4ohms for my current 2x10 setup, and if I decide to rebuild it as a 4x10 combo again someday, I can swap it to the 2ohm tap. I'm also considering having JD Newell build me 2x10 extension cabinet, then wire the 2 taps to a switch which would make the impedence at the speaker jack switchable between 2 and 4ohms depending on whether or not I was using the extension cabinet.
Tuesday, February 23, 2010
Posted by Justin Fox at 9:09 PM