WT Classic Motor Speed dragging

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tommytube

  • Jr. Member
  • Posts: 3
WT Classic Motor Speed dragging
« on: 23 Jun 2017, 11:52 pm »
I have an early 90's WT Classic with the circular hole cutout for the motor.  It was sounding a bit slow, so I started playing around with the phone app RPM Calculator.  You fire up the app and place the phone on the clamp and it'll give you the RPM speed.  It's really nice tool. 

Anyway I was at 31 something, so I bought a new NOS belt from stock from Stanalog on ebay.  After I got it and installed it, it read 33.2 again, so I was happy.  Now a month later today it was down to 31 again.

Can voltage fluctuations on the AC lines cause this motor to drag and go slower?  Or it just the belt slipping a bit?

I've seen some mention getting a wider belt to solve this.  Anybody know how to fix this?  My setup is sounding incredible except for this dragging down from 33.3 RPM.


mav52

Re: WT Classic Motor Speed dragging
« Reply #1 on: 24 Jun 2017, 12:17 am »
Its possible. And motors don't last forever.    I have the VPI Classic Anniversary.

Sorry about that. I saw classic and jumped over the fence assuming the wrong manufacturer.  Please excuse



But yes even with my TT I've noticed times that speed in influenced by fluctuating ac current.  I purchased a Roadrunner which seems to keep the speed steady even in times of ac fluctuation.   Buts possible your motor is getting weak
« Last Edit: 24 Jun 2017, 11:03 am by mav52 »

sebrof

Re: WT Classic Motor Speed dragging
« Reply #2 on: 24 Jun 2017, 02:14 am »
VPI?? Did I miss something?  :scratch:  :)

mav52

Re: WT Classic Motor Speed dragging
« Reply #3 on: 24 Jun 2017, 10:55 am »
Yep I saw classic and jumped over the fence.  Please excuse. 

tommytube

  • Jr. Member
  • Posts: 3
Re: WT Classic Motor Speed dragging
« Reply #4 on: 8 Jul 2017, 11:32 pm »
Found my speed resolution and I wanted to share for posterity.  My turntable is a Well Tempered Record Player with the round motor hole on the left.  From circa 1991.  It has been a solid center piece of a system for all those years to great effect.  Never considered upgrading as long as I can keep it working.  Sound quality is jaw droppingly good.

My 19 year old son is a musician and has a very good ear.  He could tell when the table speed was dragging by only 2 rpms.  Using the phone app RPM Calculator I was able to verify my table occasionally went from 33.2 to sometimes as low as 30.7 or so.  Like another thread mentions, it makes Johnny Winter sound like he weighs 400 lbs. 

I observed that when the incoming power was very near 120Vac, the initial speed was 33.2 or close to perfect.  After an hour of playing it would slow.  Sometimes this coincided with a drop of wall voltage to 118.9 or about there.  So my first try was to attach a variac to the motor power cord.  This allowed me to move the input voltage around to see if I could crank it up a bit.  To my surprise this didn't affect the speed at all.

The fix is related to making a slight mod to the where the roller sits on the motor spindle.  I'm not sure but this roller just sits on the motor spindle using some kind of lubricant.  The ability of the roller to move independently to the spindle meant it could be slipping.  So I took a small piece of scotch tape and put it around the metal motor spindle and then slide the roller down shimming it tightly against the motor spindle.  This worked great.  It seems my lube would heat up after the motor had been on and made the roller slip slightly as it heated up for use.  Now that it's snugly attached the speed is solidly near 33.3.

My son is ecstatic and has had some very long listening sessions now that the tone is perfect and his favorite slabs sound as he thinks they should.

Spin Lps

  • Jr. Member
  • Posts: 11
Re: WT Classic Motor Speed dragging
« Reply #5 on: 12 Jul 2017, 02:41 am »
Thanks for sharing as that is useful information. By the way, what cartridge/phono preamp are you using.