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ledgie
21-06-2011, 07:39
Hi All,

Picked up a used SL1210 at the weekend. It's in good condition with only the ground wire tab being missing.

I got round to crimping on a new spade connector tonight and then with it connected I turned up the volume on the amp with no record playing. I noticed a slight hum at high volumes. Out of curiosity, I then disconnected the ground from the amp and noticed that the hum at high volumes disappeared.

Has anyone else found they get no hum without the ground connected? :scratch:

WOStantonCS100
21-06-2011, 07:46
Have you checked to see if someone did an "internal ground mod" on the deck?

ledgie
21-06-2011, 07:49
I haven't checked but my instinct is that there haven't been any modifications.

I guess as long as it sounds fine then it's not a problem, I was just curious more than anything.

WOStantonCS100
21-06-2011, 08:15
Not a huge issue as things go; but, the table is designed to work with the ground wire eliminating hum (cart connected); so, if that's not happening and the cart and other parts of the system aren't dodgy; then, the table definitely has an issue or has been modded.

The internal ground mod is fairly common with 1200's that have been used by a DJ (plenty of youtube "instructional" vids :rolleyes:). It's one less connection they have to make or worry about. Normally, they actually remove or clip the external ground wire. If that's what it is, it's not a big deal to undo. Multiple paths to ground/earth will often give you multiple headaches (hum). Of course, if it's not causing an issue, you could just coil it up and forget about it. Not my preferred method, but... :)

Oh, and congrats on the table !!!

ledgie
21-06-2011, 08:31
Thanks Biff.

I should point out that the hum is only really heard at above normal volumes but all the same it does still disappear when the ground cable is disconnected.

I have a multimeter so can I check continuity of the ground wire without opening up the table? The other thing I was thinking about was running some solder into the new crimped spade connector to make a better connection.

MartinT
21-06-2011, 09:29
Gary - most likely the turntable has an earth path and by adding the second path you're creating a ground loop (hum). You can easily check this by using a meter between your preamp earth and a metal part of the turntable and checking for continuity. If so, then you don't need the additional earth wire.

ledgie
24-06-2011, 07:49
A little conclusion to this tale.......

Since there was no hum with the ground disconnected I left it as it was.

However today I fitted a new cartridge. I replaced the Stanton 505 that it came with a new AT110E. When I fired up everything there was a loud hum! I connected the ground cable and everything is silent again! :)

Everything is now working as expected and the ground cable is doing its job. I guess the Stanton cartridge was grounded some how. :scratch:

MartinT
24-06-2011, 11:43
Excellent - glad you sorted it. The Stanton has a metal body? It probably grounded via the arm.

ledgie
24-06-2011, 12:34
Stanton didn't have a metal body but one of the pins had a little strip of metal which looked like an earthing tab.

WOStantonCS100
24-06-2011, 14:44
Sweet! It had to be the cart or the table (or aliens). Though I must say, I've rarely come across a knackered Stanton, especially one that still had it's ground strap intact. :scratch: Interesting.

However, once again, there's that undeniable in there. The 1200 is just plain hard to kill !! The wheel of steel it is, indeed. Time to spin the black, eh! :)

DSJR
24-06-2011, 15:21
Stanton didn't have a metal body but one of the pins had a little strip of metal which looked like an earthing tab.

Stanton 500's DO have a metal body and, if they are attached to the shell with conventional bolts and nuts, not using the plastic isolation mounts the cartridges come with when new, the arm and therefore deck will be earthed to a signal earth via that little strap.

If the 505 were to be re-stylied into a superior Pickering XV15-VE (same body, different "needle"), then I'd suggest using the flying lead and prising out the little earthing strap from the cartridge. I'm just not sure about the AT110E and didn't much like the dullness in the one I had with brand new AT stylus. The current owner of said AT loves it though, so it's horses for courses. I personally think the AT120E is far better and it'll even work well with the standard Techie hgeadshell, the 110E not upsetting the mass to rigidity ratio as say a Denon DL103 does.

ledgie
25-06-2011, 09:07
Stanton 500's DO have a metal body


I double checked and you are right, it does have a metal body. ;)

So far I'm happy with the AT110E, we'll see how it breaks in. :cool:

colinB
25-06-2011, 09:25
I had a similar problem with a stanton dj cart.

DSJR
25-06-2011, 13:38
The AT110E is smooth and safe, with a touch more refinement than the ever popular AT95E. There was once an AT115E as well, with a superior stylus profile and more refinement sonically, but I think the 120E replaced it in due course.

I like the 120E very much, as long as it can still be got for £75 to £80. I've seen a few at £120 and that's madness in my book!

colinB
25-06-2011, 13:50
Ive got one with a knackered stlus. Just checked how much a replacement is and its £40. At £120 new youre paying a lot of money for the body.