Tube amp gurus look in here.

I'm trying to repair an old Dynavox record player that has a component shorting. Any of you guys know what this thing is called? How about where I would find one?

You mean that grey thing in the foreground? Looks like a plate rectifier.

http://en.wikipedia.org/wiki/Plate_rectifier

In reply to 1988RedT2:

Funny... before I even read your post my first thought was "rectifier"... but then again, I have an little Ampeg 15W tube combo that sounds great when cranked - until the output rectifier blows - so I have that term on the brain...

I'm guessing you could find a suitable replacement silicon diode rectifier, but I'm not sure if you'd need to make any other changes to the circuit. I don't think you'll find a direct replacement, but I could be wrong.

Some discussions can be found via the usual googling: http://www.antiqueradios.com/forums/viewtopic.php?t=55124

Cool! I figured if anyone knew, you guys would. Thanks!!

One of these: http://youtu.be/pLaWzMScD3U?t=4m32s

If you can't find the specs on it, try to find the specs on the tube, or the plate transformer, then go for a diode bigger than that. For example, if the tube or transformer plate tap is 600V at 1 amp, then you would need a diode rated at (preferably) about double that. I doubt it is an amp in there, as that would be a 600 watt amp (or maybe 3-400 watts out.) Might be 600V at .25 amp (250 miliamps,) and you could get by with a 1KV 1 amp diode.

If you have the model number, you can usually find the schematic using google images.

Does anyone else know of there could be any harm with replacing it with a 1N4007 or 1N5408? You could buy some 1N4007 diodes at radio shaq; they're cheap too.

One of my guys is picking up a diode and resister to replace it now. I'll either have a working record player or a cloud of smoke in an hour or two.

If you don't hear from me by this evening, I probably electrocuted myself.

In reply to RossD:

The info I found on line was to use a 1N4004 diode and a resister. Unfortunately without any specs on the circuit, I'm going to have to guess on the resister.

Do you have a switched outlet at your bench? Turn the record player on and then hit the switch. You should have your DMM attached before too. Keep that other hand in your back pocket if you're poking around with a chop stick or DMM. Rubber mats are nice too.

I might go one or even two higher in the diode series. They are sooooo cheap.

But I'd probably just make a new rectifier layout than try to do a replacement with a resistor.

I find this pdf useful: http://www.hammondmfg.com/pdf/5c007.pdf

Well, I got the diode and resister installed and nothing went up in smoke. I'm not sure the resister is big enough though. It sounds a little over driven. I'm getting 107 volts off the diode and resistor. I'm not sure if that is good or bad and without a schematic or any specs, I never will. I'm going to step up the resistor a couple of sizes and see what happens.

What tubes are in this thing? Any Chassis or model numbers? How about an overall photo of the thing showing the tubes/transformers/parts...

Could you just wire a number of diodes equal to the number of plates, in series, to get a more correct drop?

Well, I didn't get the tube numbers or take an overall picture of just the board.

Here's what I have.

At this point it's working, back together and the guy that owns it is happy. I appreciate y'all getting me pointed in the right direction.

I might have to dig around the antique shops for another one to tinker with. That was fun.

Toyman01 wrote: I might have to dig around the antique shops for another one to tinker with. That was fun.

I have plenty, some might no be too bad to ship. :)