TD 160 Ground Issue?

[Kosinki]

I'm using a stock TD 160 with a Nagaoka MP 110 cart. I've been consistently getting distortion / audible surface noise / and buzz coming from the right speaker. I also get buzz sometimes when I move the tonearm in and out of the plastic holder. I've tightened and swapped the leads numerous times which seems to work at first but the problem eventually comes back and last night I completely lost sound coming out of the right channel. Any help would be greatly appreciated.

 

[tnsilver]

Sounds like broken wiring. Use a digital multi meter (DMM) continuity test (it beeps on contact) to follow the signal path in the following segments:

a) cart pins to headshell connector pins
b) tonearm collar to Thorens wiring hub
c) wiring hub to RCA jacks
d) tonearm gimbals ground (use the metal bearing as one point) to shield of right channel RCA (make sure the ground tab of the hub is in contact with the chassis metal post).
d) The whole path a - c again

Use the following diagrams as reference:

Headshell wiring

General wiring / ground scheme

Thorens wiring hub

(the cancellation of the hub/metal post contact as marked by the red cross,
and the external ground wire marked green - are optional mods for altering the stock grounding scheme.
Ignore them for now.)

 

[Kosinki]

Hey man, thanks for the suggestion. I'll try this later tonight.

 

[Kosinki]

What part is the "collar" on the tonearm?

 

[tnsilver]

Where the HS connects. The HS got pins, the collar got sockets.

 

[Kosinki]

Oh ok

 

[Kosinki]

So everything checked out but I did notice I have this extra metal piece on the wiring hub that goes to the right channel ground, I don't know if that's unusual.

 

[Kosinki]

Also measuring from the collar to the wiring hub, the right channel ground was the only one that didn't get a perfect 0.00 reading on my multi

 

[malden]

My TD 160 sometimes buzzes. I found that brushing the tone-arm with my anti-static record brush will cure it. Weird, I know, but it works.

 

[gadget73]

I had problems with mine that turned out to be loose screws where the ground wire attaches to the sub platter. It would move and make annoying noises. Worth a check anyway.

 

[Kosinki]

The sub chassis? All the connections have tested ok. I'm starting to think it might be my RCA not making good connection with my Dynaco preamp. The inputs look pretty dirty and oxidized, same goes for my RCA as well. Gonna give them a good cleaning tonight and see if that makes a difference.

 

[malden]

Not unusual. Thorens grounds the entire TT to the right channel's shield. The flexi-thin grey wire from the sub-chassis to the main chassis should be intact, and the 5th thin ground wire from the tonearm (connects at the bottom of the wand above the pillar shaft with a screw) should be intact too. Bad RCA cables and jacks can cause ground hum too.

Thanks for spelling that out. I'll need to check my 160 and 165, both have intermittent grounding issues.

 

[musichal]

Very often, grounding issues are caused by poor contact at either end of the head-shell wires. A good cleaning - and tightening the friction pin connectors oh so carefully - of connectors and pins often solves the problem. Some folks use a pencil eraser for cleaning the pins (I prefer emery cloth). It was the first thing I always checked if I had hum from a Thorens TD-16X series, and almost always the last thing, too.

 

[gadget73]

The sub chassis?

yeah that, not the sub platter. That would be a lot more complicated.