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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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31st May 2019, 10:33 pm | #1 |
Pentode
Join Date: Apr 2016
Location: Southampton, Hampshire, UK.
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Dansette Major.
Hi guys
In the middle of restoring a dansette major and I accidentally knocked off a white wire and I forgot to take a picture of it before this happened. Can someone please tell me where the white wire from the transformer goes to please .see the pictures |
1st Jun 2019, 7:56 am | #2 |
Dekatron
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Location: Southwold, Suffolk, UK.
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Re: Dansette major
For some reason the amplifier looks to have been completely dissassembled. Why? Check that the 2 wires from pins 4 and 5 (heater winding) from the EL84's valveholder are still connected to the transformer. If so, this white wire is either the HT+ or HT- connection. If there is another wire that goes to earth then this suggests it's the HT+, but that's still a guess without being hands on with this. The amplifier being broken down into its constituent parts does not help to trace this from your photo.
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Edward. |
1st Jun 2019, 8:53 am | #3 |
Pentode
Join Date: Apr 2016
Location: Southampton, Hampshire, UK.
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Re: Dansette Major.
I took it apart because I changed the wax capacitor and one of the connections was on the circuit. That's when I snapped the wire off and didn't get a chance to take a picture beforehand
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1st Jun 2019, 8:58 am | #4 |
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Re: Dansette Major.
A bit of reverse engineering is called for, tracing the wires which remain connected to the transformer and by a process of elimination working out what the white wire is for.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
1st Jun 2019, 11:44 am | #5 |
Pentode
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Location: Southampton, Hampshire, UK.
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Re: Dansette Major.
I tried that it could have come off one of the valve pins I'm thinking pin 7 but not sure that's why I'm hoping someone has a same player or have done one and knows where it goes
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1st Jun 2019, 12:07 pm | #6 |
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Re: Dansette Major.
Let me try again. Where do the existing wires from the transformer go to? ie valve pin number, capacitor or W.H.Y?
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
1st Jun 2019, 12:27 pm | #7 |
Dekatron
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Re: Dansette Major.
It could be the valve's heater connection, on that style of amplifier the heater feed wire from the transformer was connected to pin 5 of the redundant UY85 rectifier valve socket, pin 5 was then linked to pin 4 of the same socket, and from there it went to pin 5 of the EL84's valve socket, similar to this:
https://vintage-radio.net/forum/atta...8&d=1352469495 Lawrence. |
2nd Jun 2019, 10:21 am | #8 |
Dekatron
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Re: Dansette Major.
There is no UY85 in this amplifier. It's an EL84 with a contact cooled rectifier.
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Edward. |
2nd Jun 2019, 7:21 pm | #9 |
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Re: Dansette Major.
True, but the PCB layout for an UY85 base is still there and that's where the wiring goes.....
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2nd Jun 2019, 7:44 pm | #10 |
Dekatron
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Re: Dansette Major.
If you look carefully at the OP's 2nd photo you can see the track that goes between "pin 5 " of the non existent UY85/holder and the edge of the board and at that point near the edge of the board there appears to be the soldered part of a broken multi strand cable......So far as I can make out.
Lawrence. |
18th Jun 2019, 8:23 pm | #11 |
Pentode
Join Date: Apr 2016
Location: Southampton, Hampshire, UK.
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Re: Dansette Major.
Hi guys
Have got everything back together now and I have no power going to the circuit. I have replaced the old cable with double insulated and seem to have sporadic power along the cable. I've tested for continuity that all reads fine. It seems like the last little bit of the cable that connects to the on/off pot. I can't seem to get a power reading from the cable at the switch connections either. The cable is a brand new one new plug etc. Any help please would be appreciated. |
18th Jun 2019, 8:45 pm | #12 |
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Re: Dansette Major.
Your description does not make sense. If you have continuity there is no reason why power should not reach the turntable, if not the amplifier.
Meter on ohms range. Player NOT plugged into mains supply. Clip one lead to the live pin of the mains plug and the other lead to the neutral pin of the mains plug. With player switched off you should read infinite resistance. With player switched on you should read a low resistance. Report back with your findings.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
18th Jun 2019, 8:49 pm | #13 |
Dekatron
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Re: Dansette Major.
Is the new cable decent quality stuff properly wired into a reasonable 13A plug?
Some moulded assemblies can be dubious to put it mildly. How does it check out tested cold (not plugged into mains) with an ohmmeter or continuity tester? You might just be unlucky and have a faulty bit of wire......
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18th Jun 2019, 8:50 pm | #14 |
Pentode
Join Date: Apr 2016
Location: Southampton, Hampshire, UK.
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Re: Dansette Major.
I have power at the turntable. But nothing at the amp.sorry I should have said that. Just realised how it came across. But I couldn't get a reading on the live cables.
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18th Jun 2019, 8:57 pm | #15 |
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Re: Dansette Major.
That proves that the off/on switch is OK.
Does this player have a mains transformer in addition to the output transformer or is HT derived from a tap on the motor? Does the valve light up? Can you measure any HT (DC Volts) across either smoothing capacitor?
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
18th Jun 2019, 9:25 pm | #16 |
Pentode
Join Date: Apr 2016
Location: Southampton, Hampshire, UK.
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Re: Dansette Major.
No mains transformer. But no the valve doesn't light up. I haven't measured the smoothing pot yet only the continuity of the pot.
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18th Jun 2019, 9:29 pm | #17 |
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Re: Dansette Major.
Er! I haven't mentioned a smoothing pot. Smoothing caps shouldn't have continuity.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
18th Jun 2019, 9:48 pm | #18 |
Dekatron
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Re: Dansette Major.
There's one in the photo's, it's the same type as in this:
https://www.vintage-radio.net/forum/...0&d=1372415083 Lawrence. Last edited by ms660; 18th Jun 2019 at 9:56 pm. Reason: Link added |
18th Jun 2019, 10:10 pm | #19 |
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Re: Dansette Major.
There seem to be several variants of the amplifiers fitted to these players.
The transformer in the OP's first post does look to be a mains transformer, but perhaps the OP could confirm that there's an output transformer on the other side of the PCB.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
19th Jun 2019, 8:43 am | #20 |
Dekatron
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Re: Dansette Major.
For the purposes of clarification, all Dansette "Major" record players used a double wound mains transformer, a single valve (EL84) amp and a contact cooled rectifier. A 3 core mains lead can be safely used on these.
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Edward. |