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Jumping to wrong conclusions

alanl

alanl

Active Member
The audio system in the house has been causing me grief for weeks.

I tried myThorens TD160 Mk 1 and my Silcron TTs but both had hum on one channel. Then I tried swapping the NAD 3140 amp to a Sansui amp - no improvement . Then tried with and without the mixer/pre-amp - still no change. Various tests with a multimeter failed to identify the source of the problem.

I resorted to cutting and replacing the RCA plugs on the cables - still got the hum. Finally one channel then failed completely when using the Thorens. I purchased new interconnect cables but still no joy either via the mixer or direct to the phono inputs. The VU meter on the mixer clearly showed good signals from the cartridges BUT nothing getting to the main amp and therefor no sound at the speakers.

Finally cut the OEM cables on both turntables where they exited the plinths and soldered in jack sockets. I removed the mixer from the system and used new cables from the jacks to the main amp input sockets. Worked perfectly on both channels and no hum.

I can only conclude there were TWO issues contributing to the problem. namely a dry socket in the wiring of the Thorens plus a failed output transistor in the mixer. Maybe someone smarter than me would have worked out the problem without all the hours of messing about but at least it was worthwhile eventually.

The only problem now is to replace the Thorens motor that is causing fluctuating pitch. (The Silcron is fine so it is not a power supply issue)
 
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musichal said:
If I didn't jump to conclusions, cast aspersions and throw fits, I'd get no exercise at all.
Click to expand...

That;s what I like - a fellow experimenter!

Re motor, having now checked the price of a replacement motor, I'm in shock - I'll try a Thakker belt before doing anything more adventurous. The existing (cheap) belt is a replacement from a only couple of years ago but it feels loose and the platter frequently needs a manual push to get it started. I hope the belt is what is causing the speed fluctuation
 
Just for interest, the Silcron TT was made in Australia in the early 60's and this one has a Sansui headshell, cartridge and (I seem to recall) a replacement Jico stylus. Surprisingly, the sound is actually slightly warmer and louder than the Thorens/Shure combination. For classical music and opera, it is excellent
 
We all have to learn. Some of us by schooling and some of us the hard way. I am sure you will do better the next time. Even with the school of hard nocks learning isn't easy. Just hang in there.
 
I have been "hanging in there" for nearly 8 decades! I learn something new virtually every day. Frequently listening to colleagues with similar experience, it is commonplace that we all do stupid things when we really should have known better
Smile
 
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