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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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16th Jul 2008, 12:29 pm | #1 |
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Vintage Record Player Capacitor Values
I am repairing a mains record player and will change some capacitors in the amplifier. The problem is that I do not have the circuit diagram. Some of the capacitors values seem obvious but there are some that are not even after reading the section on capacitor markings. I would appreciate opinions on the values to buy.
The capacitors are black ERB types and the markings are: Two capacitors: 5.1000 1500V and one capacitor: 2/1.000 uf 1800cm 1500v They are connected to the volume and tone controls so I think that the first would be 5pf and I have no idea what the second would be? Pete |
16th Jul 2008, 1:58 pm | #2 |
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Re: Vintage Record Player Capacitor Values
I'd have expected something like 0.05 and 0.1uF at the tone and volume controls.
In the absence of anything more helpful, can you judge the values from the type and physical size of the caps? The 1500v rating seems high to me but, as they're obviously unreadable due to age, they're likely original and not later replacements. What make/model is it? if we know that, someone may just have the cct. |
16th Jul 2008, 1:59 pm | #3 | |
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Re: Vintage Record Player Capacitor Values
Quote:
What record player is it (make)? Someone here may be able to identify it. Rich.
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16th Jul 2008, 2:10 pm | #4 |
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Re: Vintage Record Player Capacitor Values
I agree with Darren and Richard. The 1.5kV voltage rating seems very high indeed and unlikely to be correct unless the manufacturer was offered a special deal on some surplus caps. They would normally be rated at around 300V.
These two caps are likely to be in the 0.001-0.1uF range in a simple record player amp. Paul |
16th Jul 2008, 4:54 pm | #5 |
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Re: Vintage Record Player Capacitor Values
Thank you Darren, Rich and Paul for your replies.
The record player is a "Teppaz Presense". It uses an EZ80 rectifier, EBF80 double diode Pentode wired as a Triode and an EL84 output Pentode. The capacitors seem to be original and they are also marked "Tension Essai" A circuit diagram would be extremely useful! Best regards, Pete |
16th Jul 2008, 6:10 pm | #6 |
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Re: Vintage Record Player Capacitor Values
There's a clue in the "tension essai" and the odd figure of 1800cm. Believe it or not, there is a logic to describing capacitance in centimetres and the French used it. All the capacitors in a typically French radio of mine were rated in cm. 1cm of capacitance is 1.113 picofarads so for most purposes just treat 1800cm as 1800pF unless it's in a tuned circuit when you would need to be more accurate.
Actually just found this: http://en.wikipedia.org/wiki/Centimetre which says it's a cgs system unit. I think it's actually the capacitance of a parallel plate air (or vacuum) spaced capacitor with 1 sq cm plates spaced by 1cm. The other info suddenly clicked.... 2/1000 uF is just that, 2nF or 1800cm as near as. The other one is probably 5/1000 uF ie 5nF so the 4.7nF already mentioned would probably suit OK. Chris Last edited by Herald1360; 16th Jul 2008 at 6:14 pm. Reason: Sudden flash of inspiration! |
16th Jul 2008, 10:02 pm | #7 |
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Re: Vintage Record Player Capacitor Values
Chris,
thank you for a GT6 answer to the problem! I have learned something new, today and what was confusing now begins to make sense. You don't happen to know the French words for "Circuit Diagram" or "Schematic", do you? Best wishes, Pete |
16th Jul 2008, 10:11 pm | #8 |
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Re: Vintage Record Player Capacitor Values
Hi!
Its simply:- Schéma! Chris Williams PS! If your amplifier has a non-isolated chassis, (which is very possible!) then the maker may have specified 1000/1500V capacitors for safety! If you've a testmeter, you can carry out a simple continuity test between each mains lead and the amplifier metalwork to find out if its live or not & I'd suggest this, taking extra care when servicing! Last edited by Chris55000; 16th Jul 2008 at 10:22 pm. |
16th Jul 2008, 10:28 pm | #9 |
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Re: Vintage Record Player Capacitor Values
Chris,
Thank you again! I will carry out the safety check, tomorrow! Best regards, Pete |
16th Jul 2008, 11:05 pm | #10 |
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Re: Vintage Record Player Capacitor Values
Hi!
Sorry for such an awful scrawl but will this help as a guide? Chris Williams |
17th Jul 2008, 5:41 pm | #11 |
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Re: Vintage Record Player Capacitor Values
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17th Jul 2008, 6:38 pm | #12 |
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Re: Vintage Record Player Capacitor Values
Someone must have had a load of EBF80's, they would have been better using 1/2 ECC83 or even an ECL82 or similar instead of the EBF80 & EL84!
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17th Jul 2008, 10:42 pm | #13 |
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Re: Vintage Record Player Capacitor Values
Chris,
I very much appreciate the diagram; it will speed my comprehension of the actual layout and give me something to build on. Thank you very much. Best regards, Pete |
17th Jul 2008, 10:45 pm | #14 |
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Re: Vintage Record Player Capacitor Values
Maurice,
I expect that the design was intended to use up surplus stock but the valve information shows the diversity of the EBF80 and gives the characteristics for the Triode connection. I hope that I do not need a replacement! Regards, Pete |
18th Jul 2008, 2:49 pm | #15 |
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Re: Vintage Record Player Capacitor Values
Chris herald1360 is dead right about capacitance being measured in centimetres, I remember reading about this years ago in a pre-war book, as being Continental practice.
Having said that, I'd always had the impression that it was prevelant in the telegraphy industry, but as the radio and electronics industry became established they worked with microfarads from day 1 and this eventually prevailed everywhere. A capacitance of 1 centimetre is defined as the capacitance in a vacuum of a conductive sphere of radius 1cm, not quite as Chris suggests - the other 'terminal' of the capacitor being points at infinity. And yes, 1cm = 1.1126pF. It's really interesting that a record player circuit manufactured late enough to use B9A valves, has capacitors marked in cm. Fantastic! |
28th Jul 2008, 6:00 pm | #16 |
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Re: Vintage Record Player Capacitor Values
I managed to locate the Circuit Diagram (Schema) and would like to attach it here for interest but the manage attachments facility does not seem to work on my PC!
Regards, Pete |
30th Jul 2008, 9:45 pm | #17 |
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Re: Vintage Record Player Capacitor Values
I now need a replacement rubber tyre for the idler wheel that is driven by the electric motor and runs inside the record platter acting as a gear wheel and driving the record platter round. The one on the machine has a notch where the motor drive has rubbed it when the platter has stalled or, over time, the drive spindle pressure has “dented" the rubber tyre.
I managed to find the circuit diagram from this web site: http://forum.retro-phonia.com/read.p...=16956&t=16956 by searching sequentially in google-French for TEPPAZ PRESENCE SCHEME but my limited education – even with translation – prevents me from asking the French forum members for advice as to where I can buy a replacement idler wheel tyre. There must be a UK location that sells them; I would appreciate advice! Best regards Pete |
30th Jul 2008, 10:19 pm | #18 |
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Re: Vintage Record Player Capacitor Values
This thread may be of interest.
It looks like some people have had success at boiling rubber rollers to regain their original shape. https://www.vintage-radio.net/forum/...boiling+roller |
31st Jul 2008, 12:14 am | #19 |
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Re: Vintage Record Player Capacitor Values
Thank you, It is an interesting link.
The rubber tyre comes off the wheel easily; and, If I am unable to purchase a new one, I shall try the boiling method! Best regards, Pete |