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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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15th Mar 2017, 2:39 pm | #1 |
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Replacing capacitors
Hi can anybody tell me what modern value capacitors I can safely replace the following with.
1. 0.002uf 350volt 2. 0.01uf 350volt 3. 0.005uf 350volt 4. 0.005uf 150volt 5. 0.04uf 150volt Pye black box amplifier . The above caps are all original HUNTS so need replacing. Gary |
15th Mar 2017, 2:58 pm | #2 |
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Re: Replacing capacitors
1, 0.0022uf 2.2nf 2200pf
2, 0.01uf 10nf 3, 0.0047uf 4.7nf 4700pf 4, 0.0047uf 4.7nf 4700pf 5, 0.039uf 39nf All voltages to be the same as originals or higher. |
15th Mar 2017, 5:17 pm | #3 |
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Re: Replacing capacitors
A frequently asked and not unreasonable question, time for a sticky I think.
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15th Mar 2017, 5:21 pm | #4 |
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Re: Replacing capacitors
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
15th Mar 2017, 6:24 pm | #5 |
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Re: Replacing capacitors
A followup question if I may. I need to replace the mains smoothing can (picture attached) where would I track this or a modern version of?. The can only has two pins as can be seen by picture 2
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15th Mar 2017, 6:53 pm | #6 |
Dekatron
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Re: Replacing capacitors
The can is earthed. You are unlikely to get a "modern" version of what you have. You will need to buy 2 seperate electrolytic capacitors of similar (or near as) value and at least the same operating voltage. If this is in the smoothng circuit, and it looks like it, you MAY be able to use a 16uf and a 32uf. These may lower the hum level as well. We really need you to provide the make and model number of the unit so it can be can be checked with the circuit diagram.
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Edward. |
15th Mar 2017, 7:22 pm | #7 | |
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Re: Replacing capacitors
Quote:
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15th Mar 2017, 7:52 pm | #8 |
Dekatron
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Re: Replacing capacitors
That smoothing capacitor is actually 2 capacitors in one can. A 25uF one and a 12uF one rated at 350V each (uF = microfarad). The negative side of each capacitor is connected to the can, and therefore to the metal chassis of the amplifier, the positive sides are connected to the tags. Oriignally one of the tags would have had a red mark on it (possibly on the rivet fixing it to the plastic base of the can), as the writing on the can says that would be the 25uF one, leaving the other tag for the 12uF capacitor.
If the mark is no longer present you have to trace where each tag is connected to and compare it with the circuit diagram. That will tell you which is which. The nearest modern equivalents are 22uF and 10uF. Although a bit lower I think they will work. Electrolytic capacitors are never close-tolerance components. Finding a single can with the right value in it might be a problem, you may have to replace it with a pair of capacitors or re-stuff the old can (carefully cut it open, extract the guts and fit a pair of modern capacitors inside.) |
15th Mar 2017, 8:50 pm | #9 | |
Nonode
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Re: Replacing capacitors
Quote:
I wonder whether your HT reservoir/smoothing capacitor really needs to be replaced. Have you tried to reform it? I always avoid replacing this component where possible and in the vast majority of cases they will reform. If it will reform OK then it's more than likely to be fit for service. I'm sure other forum members could give you further advise on this. Regards Symon. |
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15th Mar 2017, 8:52 pm | #10 |
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Re: Replacing capacitors
0.039uf 39nf are available in 100v versions, but you need to go to a fairly specialist supplier for 250v ones.
Personally I would use the commonly available 0.047uf for the 0.04uf one as well. Mike |
16th Mar 2017, 2:05 am | #11 |
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Re: Replacing capacitors
Thanks for the help. the only versions i can find are 630v quite a lot higher than the originals, are they ok to use
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16th Mar 2017, 2:30 am | #12 |
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Re: Replacing capacitors
Yes, as I said "or higher"
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21st Mar 2017, 9:04 pm | #13 |
Hexode
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Re: Replacing capacitors
Hello All, I'm also the proud owner of a Pye BB,- a MK1- though mine sadly has an o/c primary winding on the o/p transformer,- it's not the ultra-linear model - however, I want to crack on with it and replace those Hunts caps before powering it up, but I'm bewildered by the variety of caps available:- Polypropylene, Polyester, ceramic, etc....can anyone please advise what I should use for the best as replacements....thanks!
Nick |
21st Mar 2017, 10:48 pm | #14 |
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Re: Replacing capacitors
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
21st Mar 2017, 11:21 pm | #15 |
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Re: Replacing capacitors
At the risk of re-stating something I, and no doubt other forum members have mentioned before, modern dual (and triple)can electrolytic capacitors are available from various sources, though I doubt if anyone makes a 12uf capacitor nowadays. In most cases a 16uf replacement will be OK, though the reservoir capacitor, which is directly connected to the cathode of the rectifier, should not exceed the maximum value specified in the data for the valve in question. Stockists of modern 'cans' include Cricklewood Electronics, the BVWS, and www.askjanfirst.de amongst others.
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