JVC TT-101 table speed issue.

[gary7]

Last night I let it set with power on about an hour. Shut it off, de-oxed and worked back & forth the trim pots on the board, making sure I got them back in position as before I moved them. Let sit another hour with power on. I tried running it. It held correct speed after several running from 33 to 45 for about 15 min. Checked it this morning and still holding speed. I'll check it again when I get home from work. Now I need a 5 pin phono cable.

 

[JP]

...making sure I got them back in position as before I moved them.

Sorry to say, that’s practically impossible. It takes very, very slight nudges to get those adjusted right, and the eight that adjust the drive circuit all interact with each other.

 

[EngineerNate]

Sorry to say, that’s practically impossible. It takes very, very slight nudges to get those adjusted right, and the eight that adjust the drive circuit all interact with each other.

EIGHT?!?!?

Maybe JP is the man for the job.

 

[gary7]

Oh, and this is a 120V unit. I'll still be looking for a repair guy to get it correct.

 

[JP]

EIGHT?!?!?

Yup. On the first one I repaired it took me a couple hours to rationalize the perfect-world perspective of the service manual with reality, and to learn how everything interacted. From there it’s going through the routine half to a dozen times, each pass being a refinement to get them all dialed in.

Maybe JP is the man for the job.

These days I only have time to work on my own stuff, and rarely at that.

 

[gary7]

Yup. On the first one I repaired it took me a couple hours to rationalize the perfect-world perspective of the service manual with reality, and to learn how everything interacted. From there it’s going through the routine half to a dozen times, each pass being a refinement to get them all dialed in./QUOTE]

Now you've got me scared.

 

[majick47]

Gary7 you will have to dig thru the old threads re finding info on someone to repair the TT-101, start checking Denon DP-80 as I remember.

 

[totem]

Oh, and this is a 120V unit.

So your saying you have a TT-101 that was made to run on 120 V ? Or you have a QL-10 .

 

[EngineerNate]

So your saying you have a TT-101 that was made to run on 120 V ? Or you have a QL-10 .

QL-10 is just a 120v TT-101 sold with the base and tonearm right?

 

[gary7]

QL-10 is just a 120v TT-101 sold with the base and tonearm right?

The plinth is tagged as a QL-10. The plate on the TT-101 is 120V. Does not have the 7045 arm, Arm looks like the one on a Kenwood KD-550.

 

[gary7]

You would think that Huntsville being a Tech town there would be plenty of repair shops. The only audio guy I would trust with this passed about 2 years ago. Now we only have The Geek Squad

 

[majick47]

Complete table is the QL-10, the separate motor unit is the TT-101. Much the same as how the other Japanese mfgs, Sony/Denon/Technics, offered similar units available as a complete package of motor unit/tonearm/plinth or you could pick and choose purchasing just the motor unit and providing your own plinth and tonearm. Not many but a few of the TT-101 were mounted in VPI plinths in the early 1980s.

 

[gary7]

I’ve been conversing with Dave Brown at modularsynthesis.com. This is what he relayed to me about the TT-101


"Dave Brown <davebr@modularsynthesis.com> May 16 (2 days ago)to me
I believe that turntable uses a double sided PCB but without plating, so there are no connections from front to back. The way they solved this was by putting eyelets in the appropriate places and soldering them on both sides. The issue is there is a difference in the coefficient of expansion between the eyelets and the PCB and they eventually crack the solder joint and fail.



I am fairly certain that if you pull the PCB and resolder every eyelet on both sides of the PCB that there is a good chance it will come back to life. The symptoms you describe are of an intermittent, not a hard failure, and this could very likely be the issue. I do get confused on what turntables have what technology.



On the models that use single sided PCBs, the connectors will wiggle and break the pads from the traces. On those I use epoxy and glue the connectors to the PCB so they are rigid, then use a piece of wire to bridge every trace and repair the cracks. Your turntable will use one of these technologies and those are the failure modes. I’m pretty certain yours uses eyelets.



Hope this helps.


Dave"

Last night I pulled the cover and went at the "eyelets" with my iron. I only did the exposed side. I hooked it back up. Lo & behold, the speeds locked on & held. I will eventual send to some one who can recap it and set it to specs. But nice to see it actually playing consistently.

https://drive.google.com/file/d/1tVXQwYrqXKCgcZIGnUq4EEj5hr0eI0gz/view

 

[majick47]

Gary7 terrific to hear that it was the exposed eyelets and the speed is holding, Dave Browns advice was very helpful.

 

[EngineerNate]

I'm still jealous of this score.

 

[gary7]

Gary7 terrific to hear that it was the exposed eyelets and the speed is holding, Dave Browns advice was very helpful.

Happy too. Still plan to get it to someone for a re-cap & can adjust it to specs.

 

[gary7]

QL-10 is just a 120v TT-101 sold with the base and tonearm right?

Pic

 

[gary7]

Table was missing one foot. I cobbled together one with a M6-1.0 bolt from Home Depot until I can find one or a decent set to replace them.

 

[Layesera]

You don't need a transformer for the TT-101. If you remove the metal cover from the assembly you will see the Voltage Selector you then select the voltage you need.

JVC TT-101 was JVCs TOTL table quite complicated circuitry, is it 120v or 100v, check label on motor unit, if 100v it will need a step down transformer, might cause speed issues if used without stepdown, AK member JP knows a lot more than I do about that model maybe he will see thi

 

[Gibsonian]

Last night I pulled the cover and went at the "eyelets" with my iron. I only did the exposed side. I hooked it back up. Lo & behold, the speeds locked on & held. I will eventual send to some one who can recap it and set it to specs. But nice to see it actually playing consistently.

Gary, I have a TT-101 that has issues with stop/start and running in 45 rpm, basically those buttons don't work. It only runs in 33 rpm (lucky for me) but would love for it to work properly with the stop/start and 45 rpm buttons. When you resolder those eyelets, is this from bottom side with that big cover removed or ??? I've never had mine apart, but it was recapped by previous owner.

Any pics or guidance I would appreciate.