Grado Prestige cartridges

[Dr Bunsen Honeydew]

It is very hard doing this at distance, without listening. So just to get my brain straight.

1 it is hum, it only happens when start switch is pressed on 33 (please press 45 start switch and confirm it has same problem).
2 no change in hum according to position of arm.
3 I asked you to try a earth wire to a 13amp plug from earth terminal on back of turntable as well as to phono2, does hum get worse or better.
4 if still hum take base off TT and send me pic. Pic of voltage plate doesn't help.

[Progmeister]

It is very hard doing this at distance, without listening. So just to get my brain straight.

1 it is hum, it only happens when start switch is pressed on 33 (please press 45 start switch and confirm it has same problem).
2 no change in hum according to position of arm.
3 I asked you to try a earth wire to a 13amp plug from earth terminal on back of turntable as well as to phono2, does hum get worse or better.
4 if still hum take base off TT and send me pic. Pic of voltage plate doesn't help.

[Dr Bunsen Honeydew]

Pictures don't help me I need a pic of the whole of the area under the cover so I can point you what to look at. And you need the cover off so you can try the thing I am saying.

BUT

Also reply to the questions first.

[Progmeister]

Have to be tomorrow Doc. Have to go back to work now. Sorry.

[Dr Bunsen Honeydew]

No problem I am just trying to help as I hate to see a poorly PL71.

[Progmeister]

I will check out if the same fault is there on 45 this evening as i have a busy day ahead. In the meantime here is a picture of the innards.

[Dr Bunsen Honeydew]

I have never seen this version before and it looks non standard. It is a US turntable obviously someone has imported. The power transformer has a series of tapping for different mains voltages. In the most normally seen version there is a solder strip where you resolder the position of one wire to the correct tab. The other common version which was for USA only doesn't have this tag strip. This one with an metal angle bracket and a voltage switch fitted to the top I have never seen before, it maybe there is a third version I haven't seen or it is a bodge from the guy who imported it. I cannot believe it is running without blowing up with voltage unchanged, but I have learned anything is likely with some people. What worries me is I can only see two wires going to the switch, there should be multiple wires out of that transformer for the different taps. Somewhere in this is the most likely source of your hum but still do the test with the mains plug as there is no mains earth shown. I enclose pic from my service manual.

[Progmeister]

Funk! !!!!

[Dr Bunsen Honeydew]

If you can get it to me I will sort it out for you as I have a thing for these TT and want to keep them going. It looks like you got it as a bargain because of this. Have you tried it with a MM cart to see if the hum is less.

[Dr Bunsen Honeydew]

Depending on what he has done under that voltage switch it would be best and cheapest for you to get one of these http://www.ebay.co.uk/itm/45W-STEP-DOWN ... xylk1RfkGg but first we need to look at what he has done under that switch and measure some voltages.