The PHILCO Phorum
Voice of Music 990 - Printable Version

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Voice of Music 990 - bridkarl - 10-23-2023

Just for something different I picked up a 1953 Voice of Music 990 record player for $20. Never fixed a phonograph player. If I mess it up no big deal and I get some useful parts. Strictly a casual project to see what one of these looks like inside. 

I’ve recapped this. Very easy to do. With  the layout the new electrolytic caps are just hanging in space which is bad practice but it should be OK. I replaced all the dried out bad wiring to the audio transformer, speaker, power cord. Wiring was awful - someone tacked it in place with a loop of solder. Took out the added phono jack. 
This was just something I fixed with some new caps I had in my parts drawer. Not exact values - I used a 22 mfd cap instead of a 20 - good enough. Can’t find my heat shrink tubing so I just used my normal electrical tape and plastic tubing on the electrolytics.

Once I did this it pulled about .44 amps at 110 volts which seems close to the 45 watts this is supposed to do.

The motor runs but the turntable doesn’t go. I plan to pay $10 and order a service manual. Some guy sells the instructions for oiling, motor servicing etc. About the mechanics of fixing this I know nothing but it seems all intact. All held together with these ugly little c clips which will have to be pryed off.

I have no illusions this is a restoration just casual Saturday morning tinkering. This service guy who sells the manuals and parts says “I don’t understand anything about the electrical when I asked him about the rectifier. Duh - if you care about these working you should.

My issue is this

 (1) It has a silicone rectifier. This needs to go obviously. I’m just trying to figure out what value of the dropping resistor I should use and where this should go.  I have a 1000 volt rated diode in the junk box.

(2) It has this 400 ohm resistor - this big honking wirewound pink deal which I assume is some kind of power resistor?? It should be replaced but I have no idea what wattage value. I’d assume a modern 10watt ceramic resistor would suffice.

RE: Voice of Music 990 - radiorich - 10-23-2023

Hello bridkarl ,
First all that power resistor helps drop the line voltage to supply the right about filament voltages to the tubes since between the two tubes there is 80 volt filament and our line voltage is roughly 120-125 AC .

That Set really needs a new powercord too plus that Square item with the fins on it is what they use for a rectifier it is what they call Selenium rectifier .
one thing is that they drop more voltage then the modern silicon rectifier so that power resistor R11 will need to be increased to high value .

Sincerely Richard

RE: Voice of Music 990 - GarySP - 10-23-2023

Why does that 400 ohm resistor need replacing? Wirewound resistors are usually very stable. I wouldn't change it unless is was defective in some way. TAke care and BE HEALTHY! Gary

RE: Voice of Music 990 - Eliot Ness - 10-24-2023

Yes, as Richard stated please replace that power cord. You can buy a 8' or 12' extension cord and cutoff the female end for a quick and cheap replacement.

Doesn't the service document you downloaded have the wattage listed for that 400 ohm resistor? If not I'd try something like a 25 watt chassis mount to dissipate heat. My guess is someone put in that big pink 400 ohm because the original went open or was getting very hot. Replacing the Selenium rectifier (if bad) might correct that.

462ron - 462ron - 10-24-2023

Hi Bridkarl, the filament string runs on 150ma. P= I squared x r so that 400 ohm resistor dissipates 9W. Go with a 20W or higher replacement if you’re going to do it!

Ron