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Dual 1229Q runs slightly fast at 45 RPM

Ben Rothman

Ben Rothman

Active Member
Hi guys, I have a weird problem with my Dual 1229Q. The turntable has been fully restored and everything works. I only have one very small problem. The speed on 33 is dead on. 33.32 to be exact. This is with the pitch control at 12 a o’clock. At 45, it runs ever so slightly fast at 45.66 rpm. It’s enough where the strobe clearly shows the turntable spinning too fast. 78 plays at the perfect speed as well. I’m not sure what could be causing the issue. The idler wheel is original, but has been “dressed.” All parts of the turntable have been serviced, including removing the motor and re-oiling it.

I’m a bit confused on what’s causing the issue and would love some help.

Thanks in advance.
 
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Ben Rothman said:
Hi guys, I have a weird problem with my Dual 1229Q. The turntable has been fully restored and everything works. I only have one very small problem. The speed on 33 is dead on. 33.32 to be exact. This is with the pitch control at 12 a o’clock. At 45, it runs ever so slightly fast at 45.66 rpm. It’s enough where the strobe clearly shows the turntable spinning too fast. 78 plays at the perfect speed as well. I’m not sure what could be causing the issue. The idler wheel is original, but has been “dressed.” All parts of the turntable have been serviced, including removing the motor and re-oiling it.

I’m a bit confused on what’s causing the issue and would love some help.

Thanks in advance.
Click to expand...

Being completely serious... if it didn't have the strobe would you notice? The idler wheel should not affect speed unless it is slipping which would, among other things, cause it to run slow.
 
I think we need to look at this differently.
Idler was dressed with some sort of unnecessary schmutz. I will assume you did the work.
With it, the pitch adjustment is turned up a bit to compensate at 33. This part of the pulley is damn skinny, with little contact surface.
But at 45, that same slippery idler wheel is contacting a larger-diameter on the pulley, giving it better grip.
The 78 part, I have no clue.
Get a clean idler. Needs to have nothing on it.
Clean pulley.
Sand platter contact surface using very fine emory paper. Watch the zinc oxide precipitate onto the work desk.
Take two aspirin and post an update.
 
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NoTransistors said:
I think we need to look at this differently.
Idler was dressed with some sort of unnecessary schmutz. I will assume you did the work.
With it, the pitch adjustment is turned up a bit to compensate at 33. This part of the pulley is damn skinny, with little contact surface.
But at 45, that same slippery idler wheel is contacting a larger-diameter on the pulley, giving it better grip.
The 78 part, I have no clue.
Get a clean idler. Needs to have nothing on it.
Clean pulley.
Sand platter contact surface using very fine emory paper. Watch the zinc oxide precipitate onto the work desk.
Take two aspirin and post an update.
Click to expand...
Strange turn of events. I cleaned all the surfaces and now I have unstable speeds. At 33 it will fluctuate from 33.32 to 33.07. It starts out strong at the right speed and then just slowly fluctuates down. I’m not sure what’s causing this issue. I did order a brand new idler wheel. Maybe that will help?
 
NoTransistors said:
I think we need to look at this differently.
Idler was dressed with some sort of unnecessary schmutz. I will assume you did the work.
With it, the pitch adjustment is turned up a bit to compensate at 33. This part of the pulley is damn skinny, with little contact surface.
But at 45, that same slippery idler wheel is contacting a larger-diameter on the pulley, giving it better grip.
The 78 part, I have no clue.
Get a clean idler. Needs to have nothing on it.
Clean pulley.
Sand platter contact surface using very fine emory paper. Watch the zinc oxide precipitate onto the work desk.
Take two aspirin and post an update.
Click to expand...
I’m not sure if the motor itself is causing the issue. Could that be the cause of the speed fluctuations?
 
Guess you should have not popped those two aspirin.
Dry motor bushings will heat up and slow down rotation. Matter of fact, even a pristine turntable will need time to stabilize as it warms up.
 
NoTransistors said:
Guess you should have not popped those two aspirin.
Dry motor bushings will heat up and slow down rotation. Matter of fact, even a pristine turntable will need time to stabilize as it warms up.
Click to expand...
I believe this issue was there before hand. I just didn’t realize it. The 1229Q starts out fast, and then slows down and then speeds up. It’s always drifting. I can’t get the speed to stabilize. I’m stumped. Maybe I should open up the motor again?
 
Try a drop of oil on the idler support post as well as the platter support.
My own 1229Q has a new motor and unused idler. The only speed issue is imaginary, caused by that damn printed-off-center paper strobe.
 
NoTransistors said:
Try a drop of oil on the idler support post as well as the platter support.
My own 1229Q has a new motor and unused idler. The only speed issue is imaginary, caused by that damn printed-off-center paper strobe.
Click to expand...
I will give that a try. The speed fluctuation sadly isn’t imaginary. I have an app on my phone called RPM. You place the phone on table and it tells your precisely the speed. On my table there is quite a bit of fluctuation. I’m not sure where I should start. I will mention that I have overhauled this table and it’s been working perfectly. This is a new problem.
 
I wouldn't entirely trust the phone apps accuracy though I frequently use them myself to spot check. They usually seem to have wow figures that are probably not indicative of the actual motor speed, possibly due to whatever sensor the phone has not being perfectly centered over the center. I've seen this on any drive system, not just idlers.
 
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