I recently tried replacing the tonearm wire in my Realistic LAB-430 turntable with some silver tonearm wire. The LAB-430 isn't exactly high end, but it isn't junk, either. I also took out the connecting cable (included a set of RCA phono plugs) from the LAB-430 and put in a pair of gold plated RCA phono jacks on the back. I ran the silver wire all the way from the connectors at the back of the cartridge adaptor, through the tonearm, into the turntable and to the RCA phono jacks and soldered the silver wire to the phono jacks. I was trying to decide whether to use copper Litz tonearm wire or silver tonearm wire and decided on the silver tonearm wire out of curiosity. I never used silver wire for anything in audio electronics before. Both should give good results with a turntable. After installing the silver tonearm wire I connected an oxygen free copper cable between the turntable and my Sansui QC-04 (Ed Saunders CD-4 cartridge on the tonearm) and played some stereo records. I noticed better dynamics, somewhat better dynamic range and a brighter quality in the treble. Later, I tried playing some CD-4 records, first using a quadradisc test record. I mentioned before that I put in some switches into my QC-04 so I can turn on and off the stereo preamp board and/or the carrier demodulator board. The matrix (mixer) circuit remains on all the time when the QC-04 is on. The carrier signal didn't seem high enough when I first tried it (using the oxygen free copper cable) and I got the idea of trying different connecting cables. I tried two other sets of cables and found that a thin lower quality set of cables seemed to work the best. The thin cables seemed to pass the carriers better. I could turn the carrier level down about a quarter to a third turn on the QC-04 and the green light would still remain lit on most CD-4 records. This was better than before the modifications.
One thing I found out was that the quality of the sound from the carrier signal depends a lot on the tracking force. Setting the counterweight to about 1.5 grams seemed to give the best results. I also had to loosen the screws on the cartridge adaptor and put in a small piece of sheet brass as a shim to level the cartridge. I used a test record to set up the system (adjusting carrier levels, etc.) and was able to get a lot better separation. Before changing the tonearm wire and tweeking the system, the right front and right back channels didn't seem to have much separation, but the left front and left back channels did. I thought this might have been due to the speakers and their positions in the room. After the improvements, there was better separation in all channels. I could hear for the first time the swooshing quad panning on Zappa’s Overnight Sensation album, Black Sabath Paranoid sounded powerful, Jefferson Airplane’s Volunteers album was beautiful, with better separation of the vocals and instruments and better dynamics and lower distortion.
One problem I noticed, though, was a whistling sound when the carrier light came on and there was no sound playing, which I could hear before, but might be slightly louder now compared to the premod system. This apparently is from cross talk between the left and right carriers which is a known problem with CD-4 records. Before I put in the new tonearm wire, I twisted the four wires together. After I got the wires in the tonearm and put it back on the turntable, I got the idea that twisting all four wires together might produce some cross talk, but instead of taking it back apart again, I just separated the wires inside the turntable and twisted the left and right wires into two twisted pairs, and left the ones in the tonearm twisted together. When I have time, I’ll have to take the tonearm off again, untwist the four wires and twist the left and right wires into two twisted pairs and see if that reduces cross talk. I also have a Grado F-1+ CD-4 cartridge which I want to try out later with the new mod.
I found a link where they discuss cross talk in tonearm wire. It appears according to mishak’s calculations, cross talk would be worse at the 30 kHz carrier frequency compared to audio frequencies. I also found some patents where they talk about cross talk between twisted pairs and CD-4 record cross talk.
Tonearm Internal Wiring Capacitance And Crosstalk
US 4202550 Stereo lead wires and arrangements thereof for connecting pick-up
device to amplifier
US 6433272 Crosstalk reduction in constrained wiring assemblies
US 4204091 Cancellation of interference distortions caused by intermodulation
between FM signals on adjacent channels
A picture of the silver tonearm wire is shown below.