Author Topic: SME TT Boffs  (Read 502 times)

Offline Rockit

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SME TT Boffs
« on: January 10, 2017, 03:09:52 PM »
Hi
I've had an SME 15 for over a year now and am not pleased with its speed consistency.
It went back to the factory, came back and often does a "wow" on the speed.
if one checks/sets speed with the the strobe disk it looks good but often when playing its slows and recovers. Sounds like ones playing an off-centred record!

OK. So before going into more detail, could SME owners please let me know how quickly their tables lock to the selected speed and when so, is it a "solid" lock?
I ask because my speed indicator LED flashes on and off for about 15-25 seconds before it locks and then often still flickers thereafter (an obvious indication that the speed isn't locked. This is on 33rpm. On 45 rpm it reaches speed much quicker and does a more "solid" lock. It is also, especially on 33, VERY sensitive to any contact with the platter. I understand that there shouldn't be contact but when I mess around to try figure things out if one makes the slightest contact with the platter the speed indicator flickers on and off. I would expect it not to be so sensitive.

Anyway, as mentioned, I would initially like some input from SME owners to let me know if this behaviour is normal.
This was a very expensive purchase for me and it simply isn't giving me that fuzzy feeling. Not that there's anything wrong with my wife's perceptions but she is even more sensitive/aware of the speed fluctuations. I think i may be trying to ignore them.

Your feedback will be much appreciated. (before I go into all the things I've ruled out as possible causes)

Regards

Offline grumpybear

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Re: SME TT Boffs
« Reply #1 on: January 10, 2017, 04:05:37 PM »
Sounds like the motor has way to little torque, could be be control circuitry, power supply or the motor itself.  You should be able to grip the center spindle in your fingers and it should fight you rather than just slow easily.

Maybe this will help
https://forum.audiogon.com/discussions/sme-table-owners-ever-have-a-motor-go-out
« Last Edit: January 10, 2017, 04:15:49 PM by grumpybear »

Offline Rockit

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Re: SME TT Boffs
« Reply #2 on: January 10, 2017, 05:31:17 PM »
Hi
Thanks for that. Thing is, it does have torques.
Also, the motor was initially replaced, then the power supply and then the whole TT went back to SME in the UK.
Still have the issue...
I have 3 phase power in the house so I've even taken an extension and run it off other phases.
Tried with and without power conditioner...
Rather frustrating...
Dodgy bearing? But how would one check? How can I measure the speed with 100% accuracy (over a period of time)?

Cheers

Offline fdlsys

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Re: SME TT Boffs
« Reply #3 on: January 10, 2017, 05:59:47 PM »
"15" has a 3-phase motor, it just doesn't get better than that.

Symptoms sound like problematic power supply -  voltage/current or angle of phases out of spec.

Or a greasy belt...
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Offline grumpybear

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Re: SME TT Boffs
« Reply #4 on: January 11, 2017, 08:05:50 AM »
Greasy belt is a very likely cause and the least costly option to sort out.  Make sure you clean the motor pulley and platter edge and try cleaning the belt, if all is well a new belt and find out why it got greasy to start with.

I would expect a dud bearing to be noisy or to feel rough if you rotate the platter by hand.

It should lock onto speed very quickly, maybe half a rotation, certainly not 15-20 seconds.

Offline Hi-Phibian

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SME TT Boffs
« Reply #5 on: January 11, 2017, 09:08:15 AM »
15-20 seems to long.  Maybe 3-6
As per Fdlsys I would also suspect the controller especially due to different behaviour between speeds.   

Feickert test record or Cardas sweeper have constant test tones you can use for speed measurement and the Feickert with phone app especially will tell a lot.


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Offline Francois

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Re: SME TT Boffs
« Reply #6 on: January 12, 2017, 10:52:58 AM »
On my SME 20 I had the problem, turned out the motor wasnt properly seated and I added another O-ring to keep tension on the belt. flickering stopped.


The SME 30 same, but it was belt that was dirty, actually almos oily


The SME15 looks to use same mechanism. Try cleaning belt anp spindles
Try and put a tad extra tension ? i.e. pulling the motor back a tad. Or stiffen the little o-ring pukking it back,  if it has one ?
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Offline Rockit

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Re: SME TT Boffs
« Reply #7 on: January 12, 2017, 12:12:25 PM »
Cheers Francois. Will do. Messing with motor position/tension is one thing I haven't done.

Offline Ricketysmurf

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Re: SME TT Boffs
« Reply #8 on: January 15, 2017, 10:21:53 AM »
I have the SME 30, never  had this problem, speed not locking suggests something is holding the motor back as per Francois's suggestion, though it seems strange that this doesn't happen on 45rpm.

Certainly making sure the motor is seated properly is prime. I have the feikert test set up if you're like to pop around with the t/t (Paulshof) We could exchange motors and I have a spare belt.

Andy
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Offline Rockit

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Re: SME TT Boffs
« Reply #9 on: January 17, 2017, 10:24:09 AM »
Perfect! Will PM soon.
Regards