Hi All!
I picked up this amp chassis for $20 today. No tubes or documentation included. The only markings are a stamped circle with "32E" inside. The over-all circuit appears to be push-pull using some kind of octal power tube like 6v6, 6l6, etc (pin 1 unused, pin 3 [plate] tied to one side of opt primary, pins 2 and 7 heater). Here's where the odd comes in. The screen grid pins (pins 4) are tied to the cathodes (pins 8), which are tied to what appears to be a filter capacitor positive voltage node. Both grids are tied together, and go to the 9-pin octal style socket. The power supply uses solid-state rectifiers, and appears normal enough. There appears to be both main B+ and a single-diode negative voltage source, and there is what looks like a bias POT with no guts which is NOT tied to the power tube grids. I can't figure out what exactly its purpose was. There doesn't appear to be any specific grounding scheme, as some grounds go to chassis, while others tie together in a semi-star style. My gut instinct is to just gut it and start a build from scratch. However, if this is a bit of a rare amp configuration worth a possible resurrection, I'd consider that undertaking.
Any help/input appreciated!
I picked up this amp chassis for $20 today. No tubes or documentation included. The only markings are a stamped circle with "32E" inside. The over-all circuit appears to be push-pull using some kind of octal power tube like 6v6, 6l6, etc (pin 1 unused, pin 3 [plate] tied to one side of opt primary, pins 2 and 7 heater). Here's where the odd comes in. The screen grid pins (pins 4) are tied to the cathodes (pins 8), which are tied to what appears to be a filter capacitor positive voltage node. Both grids are tied together, and go to the 9-pin octal style socket. The power supply uses solid-state rectifiers, and appears normal enough. There appears to be both main B+ and a single-diode negative voltage source, and there is what looks like a bias POT with no guts which is NOT tied to the power tube grids. I can't figure out what exactly its purpose was. There doesn't appear to be any specific grounding scheme, as some grounds go to chassis, while others tie together in a semi-star style. My gut instinct is to just gut it and start a build from scratch. However, if this is a bit of a rare amp configuration worth a possible resurrection, I'd consider that undertaking.
Any help/input appreciated!
Attachments
Last edited:
That's a Cordovox accordian amp. Output tubes were PP 7591s. They're often modified and converted for use with electric guitar or bass. If you do an internet search for Cordovox amp conversion you'll find lots of info, including schematics.
