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

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Old 23rd Sep 2022, 6:34 pm   #1
nicam49
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Default Advice sought on Dansette 'that' capacitor

Hi All, I've got 3 Dansette r/ps that have been lurking around for a few years now, and I think it's about time I did something with them. But before I plug 'em in, I want to 1stly change 'that' cap. So, can anyone advise me of the best kind of coupling capacitor to buy for them? I'm rather befuddled over all the different varieties of caps available out there.... Which type would be best suited for this function? Can anyone advise me.... Many thanks!
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Old 23rd Sep 2022, 6:38 pm   #2
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Default Re: Advice sought on Dansette 'that' capacitor

Any modern plastic film cap of the correct value and voltage rating will be fine.

Actually, the value isn't critical if you don't have an exact match to hand.
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Old 23rd Sep 2022, 8:31 pm   #3
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Default Re: Advice sought on Dansette 'that' capacitor

Can I take it that these Dansettes have valve amplifiers. If so, what models are they?
Many valve Dansettes use a single stage amplifier and as such, do not employ a coupling capacitor (That capacitor). However most have a tone control which uses a wax paper capacitor. If this becomes leaky, the potentiometer can be destroyed.
In most cases a 0.047 microfarad, 600v plastic film capacitor can be used.
There will almost certainly be other components which are past their best and require replacing.
In addition, some will use a "live" chassis, so care must be taken.

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Old 23rd Sep 2022, 8:35 pm   #4
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Default Re: Advice sought on Dansette 'that' capacitor

I was thinking that. If they use something like a UL84, then there won't be a 'that capacitor' to change, because the cartridge signal goes straight to the UL84 control grid via the volume control.
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Old 23rd Sep 2022, 8:42 pm   #5
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Default Re: Advice sought on Dansette 'that' capacitor

Thanks both! I'll dig 'em out (almost literally) and report back.
Incidentally, is it an idea to wire 2 caps in series so that if in future one cap goes leaky it wouldn't result in burning out of the o/p tx?
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Old 23rd Sep 2022, 8:46 pm   #6
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Default Re: Advice sought on Dansette 'that' capacitor

Won't do any harm, but modern caps are unlikely to fail over time.
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Old 23rd Sep 2022, 9:59 pm   #7
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Default Re: Advice sought on Dansette 'that' capacitor

Remember wiring caps in series reduces the value but increases the working voltage (as an example, two .01uF 400V caps wired in series would make .005uF at 800V). As Paul says, there is no point since modern caps (adequately rated of course) are not likely to fail.
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Old 24th Sep 2022, 9:15 am   #8
Edward Huggins
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Default Re: Advice sought on Dansette 'that' capacitor

The typical coupling capacitor ("That Cap") in th average Dansette ECL82 type amplifier is around 0.01uf, 250V. You could go for a higher value, say 0.47uf, which in theory will allow more Bass to pass.
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Old 24th Sep 2022, 5:56 pm   #9
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Default Re: Advice sought on Dansette 'that' capacitor

I think Edward may have meant 0.047uf rather than 0.47uf. I made exactly the same 'typo' in my recent Pilot record player thread where I got it correct the first time I typed it, but left a '0' out the second time. Mine has had 0.047uf capacitors fitted in place of 0.01uf by someone in the past and they work perfectly fine, you'd probably find that even the mis-typed 0.47uf value would work, but I wouldn't recommend going that high due to possible instability problems starting to rear their head. I replaced all four critical capacitors that should have been 0.05uf with 0.1uf (as it was all I had to hand at the time) in a Pye Black Box with no undesirable consequences - and you know how 'fickle' they can be!
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Old 25th Sep 2022, 9:34 am   #10
Edward Huggins
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Default Re: Advice sought on Dansette 'that' capacitor

Well spotted. Yes, I meant it to be 0.047uF. I guess this comes from a time when I often would use a slightly bigger coupling cap capacity than recommended (a dubious improvement perhaps?) as it most cases it did give more bass - or maybe I just though that it did!
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Old 25th Sep 2022, 9:58 am   #11
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Default Re: Advice sought on Dansette 'that' capacitor

Thanks All! I've also got 2 BBs, so those tips will come in handy.
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Old 28th Sep 2022, 10:41 am   #12
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Default Re: Advice sought on Dansette 'that' capacitor

Hi All, dug this one out 1st, and it doesn't have any model number or name, but I did a forum search for gp59 and found some pics from ekcoman of what looks like the same model; an Autofix, tho' mine has a switch on the side (see pic) for selecting internal /external speakers, plus a phono socket on the amp cover. Dunno if these differences mean it's an Autofix or a different model. The mat is brittle - going to try putting it on hot water to see if it'll soften so I can bend it flat, fingers crossed!
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Old 28th Sep 2022, 7:55 pm   #13
Edward Huggins
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Default Re: Advice sought on Dansette 'that' capacitor

This is a Dansette "AUTOMIX" from 1955. The switch and socket would have been added by a previous owner and not by Dansette. The reference to GP59, is to the original Acos groove-grinding Mono cartridge - and not to the record player itself.
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