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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment.

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Old 9th Apr 2010, 12:53 pm   #21
Station X
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Default Re: HMV Mono Record Player Problem

Look here:-

http://www.vintage-radio.com/repair-...apacitors.html

I always use metalised polypropylene for replacing old paper dielectric capacitors in valve equipment. For the can you'll have to use electrolytic capacitors. For the Class Ys use whatever is available.
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Old 9th Apr 2010, 6:13 pm   #22
julie_m
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Default Re: HMV Mono Record Player Problem

To be honest, it won't make a great deal of difference what capacitors you use in a record player as long as the capacitance is correct and the voltage rating is adequate.

The details of construction (ceramic capacitors have parallel flat plates; plastic dielectrics are rolled up, and so present some inductance) really only start mattering above 1MHz or so. At audio frequencies, capacitors are just capacitors.

"Class X" capacitors are used across mains live and neutral, upstream of any fuses; where short-circuit failure of an "ordinary" capacitor might present a risk of fire but not shock. (An alternative, if open-circuit failure of the capacitor is not a problem, would be to use a fusible resistor in series with an "ordinary" capacitor.) "Class Y" capacitors are used between mains live or neutral and earth, or between mains live or neutral and accessible metalwork; where short-circuit failure of an "ordinary" capacitor might present a risk of shock.
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Old 5th Nov 2012, 8:23 pm   #23
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Default The return of the HMV mono record player

Hi there.
A couple of years ago I started this thread.

Back then I had just begun on electronics, so I wasn't competent enough in fixing it. I put it in the attic and said I would take it back down in a few years when I was more experienced with electronics repair, and, well, here I am a few years later

If you read the thread, you'll see that when I first plugged it in it started smoking. I have a feeling that that was one or more of the old capacitors going kaputt, so my plan now is to replace all the electrolytics and a few of the ceramics.
My question: Does this sound right or am I just waffling?

Thanks!

Last edited by Station X; 5th Nov 2012 at 9:01 pm. Reason: Old thread reopened.
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Old 5th Nov 2012, 9:03 pm   #24
robjkmannering
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Default Re: HMV Mono Record Player Problem

Hi,

I have read the thread, several members have outlined which caps to change. The reservoir and smoothing cap are in one can. From the pictures, I can't see any wax caps but the one that stands out for immediate attention would be the big black vertically mounted one with 'Hunts' printed on it.

Make sure any replacements have a suitable voltage rating.

Have you reconnected the bass control yet?

Rob
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Old 5th Nov 2012, 9:04 pm   #25
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Default Re: HMV Mono Record Player Problem (Model 2004?)

Ceramic capacitors rarely fail.

Follow the advice given in the previous posts.
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Old 5th Nov 2012, 9:10 pm   #26
platinum95
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Default Re: HMV Mono Record Player Problem (Model 2004?)

Thanks for the replies. (and thanks for re-opening to old thread)

Yeah the older caps will be replaced, but I'm also replacing the other electrolytics anyway, because it is quite old and hadn't been on in a long time. Shouldn't be too expensive.
Also, I just checked the big cap can with a multimeter, and it does seem like two of the caps are dead in it, so they'll be the first to be replaced.
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Old 10th Nov 2012, 3:29 pm   #27
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Default Re: HMV Mono Record Player Problem (Model 2004?)

Looks like the rectifier valve is blown. Anyway I could replace this with a few diodes?
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Old 10th Nov 2012, 5:21 pm   #28
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Default Re: HMV Mono Record Player Problem (Model 2004?)

(hopefully) Final update. I've determined that the rectifier tube was blown, meaning that the other tubes would not heat up.

Ordering a replacement tube, the model 38A3 as this is an alternative to the UY85/U381.

I'll post here if it doesn't work.

Thanks all.
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