cleaning vintage receivers

Category: Amplifiers

I just picked up some fine Vintage Pioneer receivers at the local Thrift shop

Pioneer sx-450 a little static in the knobs oxidation outside veneer slight peel

Pioneer sx-424 mint but needs speaker plugs

Pioneer sx-780 looks mint, a little change inside(pennies) have powered on but have not hooked up speakers yet.

I was reading a thread from Petsound that got me started on this path and would like some suggestions on taking proper care of these treasures.

Miles Trane
I like to do a nice interior cleaning first and look for any bad signs, leaky caps, obviously blown fuses, loose wires, etc. I use a vacuum and follow up with a lightly moistened cloth. Next, I spray contact cleaner in all of the pots and switches and "wipe" the pots. After allowing at least four hours drying time, I bring the unit up, over a period of three days, with a variac, looking for overheating of the tranny, smoke, one heat sink hotter than the other, etc. If I get past this with no problems, I hook up a pair of crap speakers and let 'er rip. You may also want to clean the rca jacks with pure alcohol or contact cleaner. Just be sure to short out the power supply caps if the unit has been turned on recently before doing any work, or you may get quite a jolt. And never, never open the bonnet with the power cord plugged in. As much as you may want to see your childhood dog again, you probably don't want to under these circumstances. If you get a bit more comfy with the joys of electricity you can learn to check bias on the output devices, replace caps and output devices, do upgrades, and should probably invest in an inexpensive scope, waveform generator and cap checker. Good luck.

It sounds like you might find the Pioneer Audio section over at interesting. It is full of guys heavily and incurably addicted to vintage receivers.

Viridan's advice is pretty sound and cautious, so I'll second that (although I'm too impatient for the four day variac thing...)

Good luck!

- Harald