Dansette humming amp

[Herald1360]

Originally Posted by Boater Sam

To clarify why your circuit got pulled.
It is against the rules & copyright to publish a complete circuit downloaded from elsewhere, you can however cut and copy a part "snippet" of a circuit.

Isn't the embargo just on circuits which are available "up top" where proceeds help to support the cost of maintaining the forum itself?

I've uploaded full circuits from elsewhere which aren't available "up top" with no moderation intervention.

[picman73]

Techman you sound like my kind of guy... I did see some charging going on while metering out the 100R black resistor (the flying job ) would suggest cap OKish. "buzz test " what touch or short ? The "prince" circuit is close ... watch this space, I don't usually give up ..

[Techman]

Originally Posted by Herald1360

Isn't the embargo just on circuits which are available "up top" where proceeds help to support the cost of maintaining the forum itself?

Yes, that's correct, just the circuits available 'up-top' that are not allowed to be posted in full on the forum.

[picman73]

Sorry hate people who don't answer direct Q's
ms660 that R = red red green it is 2M2

[Techman]

To be safe, touch a insulated screwdriver blade onto each of the connections that go to the cartridge itself with the volume control turned full on and there should be a reasonable 'buzz' from the speaker when touching the blade on one of them.

It's a good idea to replace 'that' capacitor that feeds the grid of the output section of the UCL82 valve - check valve data for pin connection, or I will if you give me a moment.

[Techman]

I don't have the actual circuit diagram in front of me but you should be able to identify a capacitor connected to pin 3 of the UCL82 - counting clockwise from the gap in the pins looking from the electrical connections beneath the valve. The other end of this capacitor will come from the circuitry connected with pin 9 of the valve which is the anode of the triode section of the valve. It would also be worth measuring some voltages such as the HT at the smoothing capacitor and pins 6, 7 & 9 of the valve - these will be 'higher' type voltages, so use care and meter set on 600 volt DC range, assuming a typical DVM.

[Techman]

As a further note - there should be NO voltage, or slightly negative voltage on pin 3 of the valve. Any positive voltage on this pin indicates 'that' capacitor is failing, and if it does, it can cause a lot of damage - a photo of the capacitor when you've identified it will tell members if it's of a type that's likely to cause trouble. It may even be visible in your first pictures, I'll have to check.

[Techman]

I'd like to state that there's truth in the statement that a record player can't generally be fixed for less than £20. However, that was before we established that this unit was fitted with a two stage amplifier rather than the more usual single stage type, and that the smoothing can was probably OK after all.

The problem is that single stage amplifier types need to have a 'high output' cartridge fitted, rather than the 'medium output' type that's fitted to yours due to the additional amplification stage. High output cartridges have been obsolete for decades and are just about unobtainable now. They are nearly always duff in old record players and new, old stock ones are usually duff too, as they fail with age and not with use.

You're very lucky with this player as it has the two stage amplifier, so can be fitted with a medium output type cartridge which are still available - and at the right price if you don't want anything too elaborate.

[Station X]

Originally Posted by picman73

Sorry hate people who don't answer direct Q's
ms660 that R = red red green it is 2M2

The moderators try to keep these forums a friendly place. Expressing hatred towards other forum members isn't very friendly.

Members are doing their best to help you.

[Station X]

Originally Posted by Herald1360

Isn't the embargo just on circuits which are available "up top" where proceeds help to support the cost of maintaining the forum itself?

I've uploaded full circuits from elsewhere which aren't available "up top" with no moderation intervention.

Forum rule B8 is quite clear on this subject:-

Do not post or request service data, or links to service data, if it is for sale at www.service-data.com. The service data website funds this forum. You may post a small section from published data (such as a section from a circuit diagram or other diagram) to illustrate or help with a discussion.

What has been deleted was a FULL circuit diagram for the Dansette 14-2 and a link to another site having the same circuit diagram.

If anyone one posts the correct circuit for the OP's amplifier it will be allowed, as it's not available on this site.

Back on topic please.

[ms660]

Originally Posted by picman73

Sorry hate people who don't answer direct Q's
ms660 that R = red red green it is 2M2

Not sure about the first line of the above, nowt to do with me I presume.

Anyways, second line of the above, yes, I thought that might be the case, so far as I can make out it's connected between the triode's grid (pin 1) and chassis, see here, 1st photo in this thread:

https://www.vintage-radio.net/forum/...ad.php?t=33456

It would be good to reverse engineer the amplifier for the schematic as it doesn't seem to be available on the web.

Lawrence.

[Herald1360]

If the OP is unpractised in reverse engineering, a generic UCL82 UY85 circuit sketch would be a good start. Odd differences from the actual hardware are easier to fix than starting from scratch.

[picman73]

Before mods get me deleted... I was hating myself for not answering ms660 question... Yikes... I built Valve stuff in the 1960's. I have decided I am not going any further with this record playing pig, thanks, I mean that, your response and expertise is awesome. May your heaters always glow...