Live and Learn Story ....Re: Dual CS5000 TT.

[Almatti]

I have a Dual CS5000 TT ( I gueess it could be labelled as "vintage") since 1987. A few years ago (don't remember exactly, but circa 2018 +/- ), after a period of not playing it for some time, when I turned it on - there was a LOUD HUM emitted. Connected to my NAD 1300 Preamp and NAD 2600 AMP - still in service to this day- it was originally thought that the TT ground wire was loose or disconnected. I connected a new Clean Ground wire but the TT still emitted this loud HUM - lucky I had the Amp and lower volume because it would have Blown the Speakers (KEF 104/2s Towers - also still played today). But after giggling the RCA cables from the TT to the NAD Preamp, it would be corrected. I unplugged the RCAs form the NAD, cleaned them and re-plugged them in and it seemed fine. Thought it was an anomoly. Then I didn't play the stereo for another period until 9/2020 (yes COVID Era). The HUM was horrendous. it seemed that it was the input jacks of the NAD 1300 Preamp. I found a local stereo/Tv repair shop nearby. I brought in the NAD for a look see after speaking with the guy who owned the shop. He replaced a about 8 diodes showing me the ones that Burned. Brought it home, re-connected the TT and after playing a few minutes, it happened again!. I brought the NAD 1300 back to him and left it there where he connected it to a TT he had in the shop. He let it run ON for days. He found 1 or 2 other "suspect" bad diodes or relays (not sure exactly) - no charge. Again after re-connecting the TT but after a longer period of smooth playing - the HUM appeared again. I was able to pinpoint that the culprit was the Phono Connection. If I giggled the RCAs, the HUM would disappear. I let that be for awhile. Then when playing the stereo again nearly 2 years later for the Heck of It (I now had a new system created in the finished basement which became my "mancave" [sorry I kinda dislike that term] during COVID for work and Play until I retired in May 2021), the HUM was again back. Now we are in 2023. I researched the Dual CS5000 as the source of the problem. I discovered that the Dual CS5000 TT has had reported problems with RCA cables over the years! The RCAs are directly connected to the tone arm which would have required a complete rewiring job. I called the Stereo guy (Adam) and this time I brought the TT in. He was aware of the "issue" with the Duals... He found the fault in the RCA cabe, where he cut the cable and Spliced & soldered new RCA cable (fortunately the "break" in the RCA was about a foot form the base of the TT. The HUM was Cured after swearing it was the Phono Input jacks of the NAD 1300. The strange thing is that before having the RCA spliced I purchased a separate NAD Digital Phono Preamp with USB PP4 via Amazon, connecting it to the Dual TT and connecting the PP4 to a different input jack of the NAD 1300 - that worked without the HUM. But after the Splicing of the TT's RCA cable, the TT played fine (no HUM) connected the NAD 1300 phono input jack - no need for the PP4. Is it because the NAD PP4 is a "digital" Phono Preamp ? Who Knows. I elected to keep the PP4 for some future use (it does have a USB connector port). Sorry for the winded story, but that's How You Live and Learn!