Sansui 500-A

sbeineke

New Member
Tubes. Excellent condition. How are these things in real life? Are they considered collectible and how were they rated in the day? Have a opportunity to buy this receiver and a set of Sansui 1500 speakers. All mint. For $250. What were the driver tubes?
 
Can't answer other things but if it's in good shape and works I'd jump on it and ask questions later, at that price.
 
Tube layout below. Looks to be a pretty nice unit, Under the 1000A. At this age, even in "MINT" condition the caps are on a very short leash, with one foot in the Grave and the other on a greased BANANA PEEL! Sansui used a lot of Suzuki PIO caps that fail miserably at the most in-opportune times. The Elna Electrolytics are also suspect. Give it a good recap, and any output tubes you put in MUST BE 7189 rated (plate voltage 400V or More) SOVTEK EL-84M are very good, as are Russian 6p14p-EV (ruggedized Military old Stock). Or find 4 matching (just because a tube tester gave the same reading for emissions or gm, doesn't mean they're matched) by Cathode current at rated plate voltage, OLD STOCK 7189A. Individual Fixed bias adjustment.

Overall looks to be a Nice EL-84 based unit. If it's 1/2 the ass kicker that the 1000A is, you'll love it.

Flyer, Owners Manual and SERVICE Manual are on HIFI-ENGINE.com. Free registration.



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I just serviced one of these and it sounded fantastic. I had to do a lot of work to it but it's built like a tank. One note of caution! You can't just sub heavy duty EL84 tubes for the 7189A's that the amp is built with. Why? Well the 7189A has more than 1 pin connection for 2 of the elements. They could have used the EL84 pin out but the unit I worked on used the alternate pins. This results in no connection to the input grid or screen grid if you plug in an EL84. I rewired the bases and installed tubestore 7189 tubes and they worked very well. There's a bias control for each tube but the plate voltage on this unit was running around 425 VDC so careful tube selection is needed.

BUY IT NOW!
 
I love my 500 A. I use it mostly for Jazz and acoustic stuff and it sounds great. I bought it partially re-capped and had a technician finish the job. My only complaint is the tapered RCA plugs and the difficulty in using decent interconnects because of them. I had the bright idea of replacing the plugs myself, then I open the cover to get to them and went, "Nope". Other than that, I really have no complaints.
 
When I worked on the 500A I was more than amazed that a human had wired it. I can't imagine what it would cost to build it today. There are many components that can only be accessed by removing many other components.
 
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