Thorens TD 320 ii auto shutoff

[Sergey Green]

Hello All,
Does anyone know how to adjust the auto-shutoff on Thorens TD 320 ii? I know it is there but set a bit too far from where it should be activating. I have seen few posts on the other forums, but they are from long time ago, and are not very clear in describing it. If anyone has done the adjustment, please share your knowledge about it.

thank you,
-lg

 

[tnsilver]

You do not want to futz with that for other than a very good reason. The procedure is in the service manual (page 7) so I'll just outline it for you. It involves a shutter around the base of the tonearm with a pointy beak that obscures IR from the optical sensor and triggers the shutoff cycle. The SM calls it the "optical path". Advance the beak toward the sensor, and it happens sooner. Retract it, and it happens later. That's the mechanical tinkering end. Now comes the electronics adjustment where you have to realign the circuit voltages after the moving of the shutter. It's done with a trimmer on the PCB and you need to set a certain voltage with the tonearm at armrest and then a lower voltage at the point where the shutter enters the optical path. Note it's a PITA and may still not work in the same way on all records. It's very sensitive to where the lead out groove begins and it may differ for LP's of different eras and labels, as for singles and 45's.

 

[Sergey Green]

I see. So it is better not to touch it, as I read it from your post. There is not any good reason for it really, other than convenience. Nice to have. But then if it shuts off in the middle of the last song on one record, and does not disengage at all on the other - that sounds like real annoyance I guess.

Service manual page 7, thanks, I will look at it.

 

[Pars]

@Sergey Green
Did you ever have any luck getting this fixed? I have the same problem on mine (same table). I've read some threads on Vinyl Engine regarding this, but they aren't clear as to what was actually done. One person used a service place in Florida, who said they adjusted the speed sensor (??) from 40 to 60 to 100 ohms. Not sure what they were referring to (Tp3 to ground resistance? Other?) and Vinyl Engine a) locks threads so I can't post in it, and b) new posts need to be approved by the moderator who doesn't seem to be around.

I've looked at the shutter on mine and I can adjust it, and will recheck it now that I have a better understanding of where it should be. I'll next take the TP3 voltage measurements from the service manual and perhaps try to check the other test point voltages as listed in the SM.