RCA tube preamps and power supplies
Preamp and line amp modules with power supplies. Two MI-12172-A/SH-1A preamp modules with RCA MI-12399 nine-pin plug-in input transformers, 250:50K. These seem to be well thought of input transformers, and these test as good, I see them selling consistently by themselves in the $80-100 range. Four MI-12173-A/SK-1A line amp modules, two of which could be used as line amps following the preamps, the other two of which could be used as tube DI’s. Wiring loom with 5 total mating connectors, one module has been directly soldered. Two PSU’s, only one needed here with one being a spare. One has broken wafers on both can caps, the other looks pretty solid. None of this is tested with power. Expect rebuild or mod time investment. The amp modules were all originally mounted on the same panel by the rotary control nuts. The preamp has both interstage volume control and a switch that disconnects the input transformer, could be used for DI use. There is a thread about the preamp here somewhere with mod ideas. Schematics below.
$250 plus shipping/insurance on 15 lbs, box roughly 20" x 15" x 10".
Preamp and line amp modules with power supplies. Two MI-12172-A/SH-1A preamp modules with RCA MI-12399 nine-pin plug-in input transformers, 250:50K. These seem to be well thought of input transformers, and these test as good, I see them selling consistently by themselves in the $80-100 range. Four MI-12173-A/SK-1A line amp modules, two of which could be used as line amps following the preamps, the other two of which could be used as tube DI’s. Wiring loom with 5 total mating connectors, one module has been directly soldered. Two PSU’s, only one needed here with one being a spare. One has broken wafers on both can caps, the other looks pretty solid. None of this is tested with power. Expect rebuild or mod time investment. The amp modules were all originally mounted on the same panel by the rotary control nuts. The preamp has both interstage volume control and a switch that disconnects the input transformer, could be used for DI use. There is a thread about the preamp here somewhere with mod ideas. Schematics below.
$250 plus shipping/insurance on 15 lbs, box roughly 20" x 15" x 10".
