E.A.R. DeLuxe record player.

[Techman]

Originally Posted by parlourtw73vs

I then put a star washer on top and then tightened down the nut.

That sounds pretty good to me and rules that out as a cause of any of the variable hum.

[parlourtw73vs]

Graham, the cap that blew was the 25uf one. Might it be a good idea to replace both Plessey caps with the black and silver ones which I have?

[Techman]

Originally Posted by parlourtw73vs

Techman your comments are a great encouragement to me, I did wonder if it was the large capacitors reforming. I've been feeling both the large capacitors, particularly after taking the large batch of readings from the valve pins, both had very slightly increased in temp. the metal can slightly more than the yellow dubilier but nothing like the warmth radiating from those wire wound resistors as you commented. I feel as though I'm making progress, but more importantly I think I'm beginning to understand the circuit and how the components are relating to it.

You're definitely getting on very well with this player.

Any warming of the capacitor cans above the ambient temperature of the room, and which is not being caused by a nearby hot valve radiating heat to one side of them over a relatively short time will indicate that there is still some internal electrical leakage taking place. Don't worry too much at this stage as they may recover a bit more as the unit is powered down and then powered up again, but keep monitoring the cans for temperature. It's not the end of the world if you have to eventually fit a replacement for the double capacitor can due to continued electrical leakage and unacceptable hum level still evident.

At least you won't have to replace those old selenium rectifiers, as they seem to be doing the job they're supposed to do quite well enough, which will save you the hassle of working out the value of a series resistor to use with the silicon diode replacement that would have been needed.

[parlourtw73vs]

I was going to ask if you would consider it a good idea to replace those rectifiers. The only player I've worked on electronically in the past was a Hacker Gondolier and that was only to replace "Those Capacitors", but the construction and point to point wiring of that was a world away from this nightmare conglomeration which is condensed under the chassis of this little E.A.R. Nevertheless, I'm hoping that its reproduction will be of a better than usual standard when it's finally sorted. It's a very elegant little unit.

[Station X]

Originally Posted by parlourtw73vs

Graham, the cap that blew was the 25uf one. Might it be a good idea to replace both Plessey caps with the black and silver ones which I have?

Do the minimum required to get the player working. You can replace all the electrolytics later if need be.

[parlourtw73vs]

OK. I've replaced the blown cap, switched on and everything seemed as before with regard to the hum. I then reconnected the leads from the pick up cartridge including the green earth lead and connected in the GC8. When I switched on again the hum was back to its loud volume and upon scraping the stylus with my finger I got no output at all. I then replaced the GC8 with my stereo cart. but I was only able to connect to 1 side of it as there are only 2 leads and i wasn't going to bother bridging the cart. at the moment. Upon switching on again the hum remained as before but this time when I stroked the stylus I distinctly heard a slight scratching in the loudspeaker. Because the hum is so pronounced it was only just audible but it was there. As a last check I removed the earth lead from the deck to the amplifier but this made no discernible difference. I finally removed the remaining leads from the P/U cart. and the hum returned to its previous much lower level.

[Station X]

There may be some residual hum due to dodgy smoothing capacitors. What you're experiencing though is mains pick up by the wires leading from the cartridge to the amplifier or possibly by the cartridge itself. It's a sure sign that the amplifier is doing its job.

Looking at the pictures in post #1 I can see what I assume are three wires in a grey sheath going to a tag strip under the deck. Two of these are commoned at the amplifier end. How are these wires connected to the tag strip and hence to the cartridge?

I also note that the two wires from the volume control to the cartridge are routed very close to the red and black wires carrying full mains to the rectifiers. Pick up could be occurring here. Separate the wires if you can.

[parlourtw73vs]

Thanks for the suggestions Graham, I'm heartened that you think the amplifier is basically working now. I've uploaded 4 images. The first one shows the underside of the deck where the green earth lead is attached by a tag to the metalwork. The screened lead is merely held in a sleeve here and doesn't appear connected to the metal base at all. The second photo shows the screened lead emerging at the end of the P/U arm, again the screening braid doesn't seem attached anywhere. The third photo shows the on/off & volume control, the 2 leads which connect to the P/U lead sockets are held up with my meter probe and each has [I think] a circular capacitor in line whilst the 2 leads carrying the mains to the rectifiers are twisted together and going off to the left in the photo. Are these the leads you mean? The 4th photo is me holding the screened P/U lead showing the braid commoner with the blue lead. Do you have any suggestions as to how I may separate these leads to try and eradicate this hum?

[Station X]

What's going on in picture 1? Is that a join in the cable and do I see a cable tie?

Does the brown wire dissapear in the joint if that's what it is?

[ms660]

I think that would warrant an ohms test from red, blue, screen at the cartridge end to red, blue, screen at the plug end.

Lawrence.

[parlourtw73vs]

Hi again. In picture 1 there is actually nothing "going on" but I can see why you would question it. In essence the black that you can see is a plastic sleeve which is protecting the P/U cable where it is secured by a metal clip. The whole is fastened to the metal body of the deck by a screw which also fastens the green earth lead. I've uploaded a photo to show this dismantled, the black sheathing was brittle with age and has disintegrated and as you can see the grey P/U lead is unbroken. It goes from the cartridge end of the P/U arm right through to the little plugs at the amplifier end in an unbroken run. The screening braid only appears to make any kind of contact with the player when it is soldered together with the blue lead into the pin which plugs into the second socket from the left on the paxolin strip on the amp. chassis. Do you think that unsoldering this screening braid from that pin might make a difference to the hum?

[Station X]

My personal view is that the screen shouldn't be connected to the blue signal wire, but instead should be earthed at the deck end.

Others may have different ideas.

You could also try swopping over the plugs in the sockets.

[parlourtw73vs]

I'll wait and see if any more suggestions come in and see if some sort of consensus appears as to which is the best configuration to use with this lead before actually doing anything to it. I hadn't thought of simply switching the leads, could be a good call there Graham. As it is presently configured it appears original, but then again after that smoothing cap. being connected incorrectly and the motor leads being in the wrong sockets who knows. With regard to to the screening braid being connected to the deck, when I install the new cartridge holder it will have to be fastened by 2 screws through the top of the arm, I think there are 2 pre drilled under that silver Garrard badge, and it would be possible to strip the lead back and trap the braid against the metal arm, does that sound a good idea?

[Station X]

It would be just a few minutes works to disconnect the screen wire from the pin, reconnect the cartridge and see (hear) what happens. You could then try earthing the screen wire at the deck end.

[parlourtw73vs]

OK, I'll give it a go and report back.

[parlourtw73vs]

I've disconnected the screen braid from the blue lead and coiled it out of the way. I've made a temporary bridge across the pins of my stereo cartridge to bring both channels into play. I remade all the connections as before and switched on. WHOPEE!!! sorry for that, but when the amp warmed up there was very little hum which did increase as the volume was advanced but not to a worrying level. When I scraped my finger across the stylus there was quite a loud reaction from the speaker so I'm now expecting to get some reproduction when the player is re assembled. I've now got to mount the stereo cartridge properly and put everything back together. I assume that connecting that screen to the blue lead was another good idea by whoever had a go at this player before, they certainly seem to have had some strange thoughts. When mounting the bracket for the cartridge do you think it a good idea to bring the screen braid into contact with the metal head shell or simply leave it as is? I'm pretty sure there was no contact before as there is no braid emerging from the grey plastic sheathing containing the P/U leads at the cartridge end.

[Station X]

That's good news. I'd leave the screen disconnected in the arm, but you could try connecting it to the plug with the green earth wire. There are no safety issues here because the earth connections are separate from the "live" chassis.

I'm beginning to doubt whether the replaced section of the smoothing capacitor can is actually faulty. Possibly a previous owner mistook mains pick up for mains hum and fitted the yellow Dublier capacitor in an attempt to cure it?

[parlourtw73vs]

OK, I'll attach the braid to the green earth lead, as you say it shouldn't have an effect on the hum. If I remove the -ve lead of the Dubilier capacitor from the main chassis will that take it out of circuit and prove if it is needed or not? Finally, before starting reassembly I reconnected the GC8 cartridge and on scraping the stylus I got a very acceptable noise from the speaker. I know it's my player but what do others think, should I fit the stereo cart. or leave it original?

[Station X]

The Dublier capacitor is REPLACING one of the caps in the can. It's not connected in parallel with it.

If you want to try disconnecting the Dublier capacitor you'll need to connect the wire wound resistor and red wire connected to it to the unused tag on the can.

See pictures in post #122.

[parlourtw73vs]

I connected the screen braid to the green earth wire, switched on and the hum was as loud as before. I then removed the screen and the loud hum still remained. As a test I removed the green earth lead, still the hum. I then removed the P/U leads and the hum dropped back to its low level which responded to the setting of the volume control so it would seem the hum is being induced by the P/U leads. Why it operated correctly previously giving a good output from both cartridges I don't know. The only change I made was soldering that braid to the green earth wire, after that it all seemed to go wrong again. Any Ideas?