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Sony SX-434 works!

I posted some time back about powering up the SX-434 reciever after it had been unpowered for some years. Using a variac I slowly brought the power up. Then today I plugged an mp3 player into it and wired up some speakers and it sounds great! Thanks for the advice folks. BTW, I took the cover off to look inside for anything amiss. It was all clean inside, no corrosion, nests, bugs, or bulging caps. There are two devices that look to me like tubes with metal cans over them. Did this thing really have a couple tubes in it? Thanks, Eric

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Reply to
etpm
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Sony SX-434 (for which I find no references) or Pioneer SX-434?

The Pioneer SX-434 doesn't appear to have any vaccum tubes, according to the service manual. It does have a couple of large electrolyic filter capacitors - 3300 microfarads, 25 volts "working volts". These are located along the left side of the metal chassis, nearer the front than the back, right in front of the big squarish power transformer.

I'm a trifle disappointed, though... the schematic says that the "no signal" voltage on those power supply rails is +/- 24 volts. That's very close to the maximum rating of these caps... not much safety margin. If you ever have this receiver in for service (or want to play with it yourself), it might be worth replacing these caps with

3300 (or a bit larger) 35-volt caps, just to make sure they aren't ever overvoltaged and shorted out by a momentary surge in your powerline voltage.
Reply to
David Platt

Thanks for posting back with results! It helps everybody calibrate their advice for next time.

Probably not. Those are probably the electrolytic filter capacitors for the main positive and negative power supplies. Most smaller electrolytic capacitors of that vintage have a plastic sleeve (often blue, green, or black, but anything is possible) over the metal can. Some of the larger ones didn't have plastic outer sleeves then - usually it was just plain aluminum. Usually there is a size and voltage rating either stamped into or printed onto the aluminum.

If there is something like "3300 uF, 50 V" printed on the cans - the numbers may vary but the "uF" and "V" marks will be there - then these are indeed the capacitors. They may also have a "+ + +" or "- - -" or a stripe to indicate polarity.

Matt Roberds

Reply to
mroberds

** The cans are square - right ?

And in the tuner section.

IF transformers have such cans over them.

.... Phil

Reply to
Phil Allison

Sony, hmmm. Yeah, that was baloney. The reciever is indeed a Pioneer. Don't know why I though it was a Sony. Thanks for the info about the "tubes". The items described by you and their location match what's in the thing. Thanks, Eric

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Reply to
etpm

As it turns out David Platt also correctly identified them as caps. Thanks, Eric

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etpm

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