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Repair / Help Forum => Repair / Help => Topic started by: scorpio333 on March 28, 2017, 06:00:03 PM

Title: Low right channel out of cartridge
Post by: scorpio333 on March 28, 2017, 06:00:03 PM
This has me stumped. Bought a new ceramic cartridge for my jukebox and can't get the right channel level with the left. Some mods have been done on this jukebox since the amp is toast. The tonearm wires come out of the arm into a connector for RCA jacks. The RCAs originally went to the amp. I use them to go into a Pioneer with ceramic input.

The original cart had a proprietary plug connection, the new cart has the typical four posts. I snipped the original tonearm wire and soldered on connectors. Very low sound out of right channel. Swap the tonearm leads, very low sound out of left channel. By very low it's maybe 10% the volume of the other channel. I went over all the connections and couldn't find a problem.

I put the cart on my technics table and get equal volume in both channels.  ???

Back to the jukebox, still one channel is low. I took the tonearm off and pulled all the wiring. I dug in a box and found an old wired mouse. Cut the cord and rewired the tonearm. Barrel connectors on one end for the cart, male RCA plugs on the other end.

INSERT all the expletives you can think of and then multiply by 3, damn thing still has very low volume out of the right channel.

I did put a MM cart on the arm and had the same volume issues.

I'm now wondering if the azimuth of the stylus is off and just not even catching the outer side of the groove. Another thing, the green ground wire off the cart terminates half way down the arm on a small clip.

Anyone have any ideas?
Title: Re: Low right channel out of cartridge
Post by: MacGeek on March 28, 2017, 09:40:45 PM
Can you disconnect the green ground?  If so, after disconnecting it, if the problem is not gone, try extending and connecting it to the jacks, or whatever connection there is to the amp.  With a ceramic cart, any high level input should work well enough to test the output
Title: Re: Low right channel out of cartridge
Post by: Sir Thrift-a-Lot on March 28, 2017, 10:13:14 PM
If you scrape your finger across the stylus, is it loud in both channels?   My guess is wiring.
Title: Re: Low right channel out of cartridge
Post by: scorpio333 on March 29, 2017, 11:26:03 AM
Thanks MacGeek, extending the green ground worked! I extended it and tied it in with the blue ground and RCA grounds. As a nice bonus, it also greatly reduced a horrible hum that was next on my list.

This jukebox has been a crazy project. Mechanically, it's working as I'd expect it to. There have been tons of gremlins to flush out and a few parts to replace. Using an external amp for now at least buys me some time to get the internal amp back from the dead, that's going to take awhile to sort out.
Title: Re: Low right channel out of cartridge
Post by: MacGeek on March 29, 2017, 05:41:10 PM
Glad to hear things are working.  Hum problems are sometimes tricky to trace and I didn't know it was a symptom (better lucky than good)