I found a Sansui SM320M stereo reciver that the mice had been living in. I cleaned it a bit and pluged it in, the tubes warmed up and it made some noises in the speakers that I had hooked up. The tuner section is complete rubish after having mice chewing on everything, so I would like to try to build a stereo amp from what is salvageable. It has really nice transformers and the power tubes are 6bm8.
I did take some voltage measurements, and found 225vdc on pin 7 and the the filaments came on so the power transformer looks ok. The output transformers are tapped and this is a push-pull. I am a total novice but have been fooling around with stuff for years. I have already started dissambling this unit, and now that I have the power transformer on the bench, the higest voltage I can find coming out of it is around 60 volts. I did find voltages as high as 285 vdc in the circuit. Is it possible or likely that there is some voltage multiplying being done by other components. I have never been able to find a schematic for this unit, and expect I will be building this amp from a similar design that I can get a schematic for. I plan to use a modern mag phono cart. Should I plan for a seperate phono preamp or could I include it on the same chassis.
Thanks for any help you can give me, Joe

I have no experience with Japanese tube audio equipment, so I can't speak to the power supply issue; but it seems to me that it would be desirable to have the preamp located as close to the turntable as practical if there has to be a long cable run between the turntable and the amp. That would minimize the line loss to the very low output signal from the magnetic cartridge, and allow a high-level preamp output signal to be run to the main amp. However, if the turntable is always going to be located within a few feet of the amp (with a correspondingly short cable between the two) it doesn't matter much which way you go.

:I have no experience with Japanese tube audio equipment, so I can't speak to the power supply issue; but it seems to me that it would be desirable to have the preamp located as close to the turntable as practical if there has to be a long cable run between the turntable and the amp. That would minimize the line loss to the very low output signal from the magnetic cartridge, and allow a high-level preamp output signal to be run to the main amp. However, if the turntable is always going to be located within a few feet of the amp (with a correspondingly short cable between the two) it doesn't matter much which way you go.
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:I have no experience with Japanese tube audio equipment, so I can't speak to the power supply issue; but it seems to me that it would be desirable to have the preamp located as close to the turntable as practical if there has to be a long cable run between the turntable and the amp. That would minimize the line loss to the very low output signal from the magnetic cartridge, and allow a high-level preamp output signal to be run to the main amp. However, if the turntable is always going to be located within a few feet of the amp (with a correspondingly short cable between the two) it doesn't matter much which way you go.
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That's a really good point. Even though I know about small signals having transmission issues, I've never thought about it as it relates to phono. That's one more good idea I can use to try to get good sound. Thanks, Joe