Technics SP 10 Speed Problems

[rollinr]

I have enjoyed my Technics SP 10 Mk II for many years. Recently though, it began to...what sounded like...loose sync. It would
wow momentarily, then resume at speed. Slowly, the wows became more frequent, and then, it stopped running at any correct speed alltogether. It spins very fast...faster than 78 rpm.
Any ideas from the most knowlwdgable diy members or gurus?
Thanks!

[Netlist]

Rollinr,
I don't know the SP10 but if it has the same electronics as the SL1200 I could maybe help you.
If not, ignore this post.

/Hugo

[Elso Kwak]

Originally posted by rollinr
I have enjoyed my Technics SP 10 Mk II for many years. Recently though, it began to...what sounded like...loose sync. It would
wow momentarily, then resume at speed. Slowly, the wows became more frequent, and then, it stopped running at any correct speed alltogether. It spins very fast...faster than 78 rpm.
Any ideas from the most knowlwdgable diy members or gurus?
Thanks!

Hi rollinr,
The two SP10's I repaired had detoriated powersupply electrolytic caps. Some were even at the point of bursting!
I replaced all electrolytics in the remote powersupply and it worked fine again. I first searched in the speed control circuit but ended in the powersupply. Especially the capacitor that gets slightly warm was very bad.

[moamps]

Originally posted by rollinr
[B]I have enjoyed my Technics SP 10 Mk II for many years. Recently though, it began to...what sounded like...loose sync.

Hi,
I have service manual for SP10 in pdf, but it is huge. (5-6Mb). If your mailbox is large enough, just mail me the address.

Originally posted by Netlist
I don't know the SP10 but if it has the same electronics as the SL1200 I could maybe help you.

Those turntables have completely different electronics.

Regards

[rollinr]

Thanks netlist, fof the offer, but the SP 10 is really a different animal. There are 4 (at least) circuit boards under the platter that are populated by scores of ICs...then there's the outboard power supply!

Elso, I'll give your idea a try. Replacing 20 year old caps couldn't hurt! Was runaway speed the problem you had encountered?

Netlist, thanks for the offer of the manual!

Warmest Rs

rollinr

[Elso Kwak]

Originally posted by rollinr
Elso, I'll give your idea a try. Replacing 20 year old caps couldn't hurt! Was runaway speed the problem you had encountered?
Warmest Rs

rollinr

Hi,
Yes and very irregular movement of the platter as there was a huge ripple on the supply.

[Panelhead]

Originally posted by Elso Kwak



Hi rollinr,
The two SP10's I repaired had detoriated powersupply electrolytic caps. Some were even at the point of bursting!
I replaced all electrolytics in the remote powersupply and it worked fine again. I first searched in the speed control circuit but ended in the powersupply. Especially the capacitor that gets slightly warm was very bad.

Elso,
Somehow I have ended up with a mint SP 10 Mk II, a mint SP 10 Mk I, and a ragged out ex radio station MkII.
The Mk II locks and never drifts. The Mk I wanders a lot. The ragged one does not have a working strobe, speed selection switch, or other nicities.
I assume you fixed two Mk II's. I have never looked inside the remote box. How many caps are in there?

George

[Elso Kwak]

Originally posted by Panelhead


Elso,
Somehow I have ended up with a mint SP 10 Mk II, a mint SP 10 Mk I, and a ragged out ex radio station MkII.
The Mk II locks and never drifts. The Mk I wanders a lot. The ragged one does not have a working strobe, speed selection switch, or other nicities.
I assume you fixed two Mk II's. I have never looked inside the remote box. How many caps are in there?

George

Hi George,
No I repaired only Mk I's. There are a handful of electrolytics inside. Just have a look. The bad ones have bursted or convex rubbers. Strobe lights also burn out in the long run.

[rollinr]

Trusting that replacing the caps will solve my speed problems, I move on to the burned out strobe in my SP 10. Does anyone know a supplier for these apparently high end neon lamps. Is the voltage the same as a small night light style neon? Any ideas? Thanks!

Rollin

[Elso Kwak]

Originally posted by rollinr
Trusting that replacing the caps will solve my speed problems, I move on to the burned out strobe in my SP 10. Does anyone know a supplier for these apparently high end neon lamps. Is the voltage the same as a small night light style neon? Any ideas? Thanks!

Rollin

Hi Rollin,
I replaced the neon lamp by a smaller standard bulb.
It did not last as long as the original lamp.
With some modification a ultra bright LED would work perhaps.