Turntable output upgrade

tecmo04

So a while ago I bought a used thorens tt. The right channel on the audio out cuts in and out. Thr cable is soldered to a pcb internally. I want to take a spare audio cord I have lying around, cut off one end and solder it to the pcb.

Overall goal is to fix the audio issue and upgrade the cable.
Anyone have experience with this that can lend a hand?

Pics to come soon

SCompRacer

You can disconnect the cables and do a continuity test to ensure that is the problem. Some tables had contact points that disconnected when the tonearm was parked. If your wires go from the tonearm to the PCB, you don't have what I described.

How much do you want to spend? I've spent hundreds of dollars on turntable interconnects. Now I just use coax. Many turntables were supplied with coax IC's due to the shielding properties. You can buy coax by the foot or cut an old S-Video cable apart. The better quality S-Video cables will have two lengths of coax, usually in different jacket colors so you won't mix up right and left channels.

Just strip the outer jacket, twist the braid together for the ground, and the center for the R an L +. You do have to be careful connecting them to RCA's. I tin the end of the exposed braid so a strand won't flake off and possibly short to center terminal. Sometimes I'll also use short heat shrink on the center conductor to insulate. They also make RCA's for coax cables, but you can make a standard RCA connector work. For a nice finished look, use some Techflex sleeving over them. Mine are together in Techflex until a few inches from the end where they branch out individually. Makes them easier to connect.

tecmo04

Thanks for the quick response! At this point I plan on spending $0! I have a few quality audio l/r cords not in used from when everything switched to hdmi.

Why did you use s-video over regular cords?
Is it as simple as de-soldering the old wires, cutting of the one end of a l/r cable, stripping it and re-soldering it to the same points?

Thanks

SCompRacer

Not all interconnects use coax, and S-video used the smaller diameter which is easier to work with. If you have desoldering and soldering skills, it is easy. Use the center conductor for the pos and neg hot, the braid for pos and neg ground. I use coax because it is resistant to RFI. With regular wire you need to twist them together and/or wrap with foil.

tecmo04

well after some procrastination i finally had time today to perform some surgery. Process pretty straight forward and simple.

1- dismantle bottom board
2- take multi meter and verify + and - for current wires
the right channel sound came in and out and the multi meter verified the wire was bad
3- desolder current wires
4- cut ends off new wires, strip and prep
5- solder new wires
6- reassemble!

First Impressions:
The whole project took about 35 minutes and definitely worth the results. The sound output is much louder and cleaner than before. I used to listen with my amp in around -18, now the same result at -30. Also, the right channel is now secure and normal. Less background noise too.

Next project will be swapping the feet for some spikes!!! Not sure if it will improve the sound but I like the way it looks...

SCompRacer

Kewl! Nice work!

Joe08867

Nice job..

ViperZ

Are those AR stereo cables? Looks like I used identical cables to re-wire my Dual 1228 a couple of years ago. But I went a bit further - installed two RCA connectors in the back of the plynth, so I only ran short cables between the PCB and those two connectors.

tecmo04

they are! AR performance series directional balanced stereo wires. I bought them before fancy schmany hdmi, coaxial, and optical.
I was thinking about adding plugs but i didnt want to modify the enclosure. taking out the saw was a little more over whelming than a little soldering. It would be nice to just have plugs though...

Maybe for the next project?!?!
Any pictures of your mod?

SCompRacer

I've had tables with it both ways. Some folks prefer to minimize connections between the cartridge and phono pre, some like to add different IC cables between the turntable and phono pre. With low output cartridges, I like to go the minimal route.

This was my last tonearm wiring repair, replacing some 'modded' coax in a MG-1 linear tracking air bearing arm. It was a tight fit. The arm originally came terminated with a box housing female RCA's. I terminated with male RCA's. This uses even smaller coax than the stuff I had mentioned earlier.

http://www.polkaudio.com/forums/showthread.php?119081-My-Lenco-Turntable-Project&p=1752370&viewfull=1#post1752370

ViperZ

There isn't much to show. Drilled two holes, added two connectors. Looks clean and works with my MM carts (ADC and Shure).

SCompRacer, I have never used MC cart on that table, but the same question really got me thinking a few weeks ago. I mean it's a critical path from cartridge to the phono pre, so you'd want to minimize the amount of noise and minimize all the losses. I never had problems with MM carts, but would be interesting if someone used MC cart with such mod.

SCompRacer

There are tonearms that come with female RCA termination blocks requiring interconnects to get connected to the phono pre. I've used low output (.25mV) cartridges with them. My tonearm was originally supplied with such a termination block. I can't recall any difference going to the male RCA's, eliminating the connector block. No change in position on the volume knob to get the same SPL's. I do clean my interconnects and sockets once a year to ensure good connections and like to keep the phono IC's short (1 meter max).