Thorens TD 160B MkII running fast?

[smg1965uk]

Recently picked up Thorens TD 160B MkII and decided to check the speed using an android app called RPM Speed and Wow.
On the 33 setting I get a speed reading of between 33.8rpm and 40rpm, 45rpm is fast as well. I have ordered a new belt, could arrive today, but this seems a bit high!

Anyone any ideas?

Thanks,
Steve

[struth]

belt too tight maybe.. they are inclined to run slightly fast, but not enough to be audible.. think it was designed that way to take acount ot belt stretch.
But your belt could be dodgy, the motors are often 220v so if mains is significantly higher its possible for it to speed up a bit

[Barry]

The Thorens 160 turntables use a 2-phase synchronous motor, so should only depend on the mains frequency.

A new belt is certainly worth trying.

[struth]

indeed although ive found the voltage did make a difference. when i set my output to 220v it worked a lot better, although it may have been the 50hz and i imagined it. its rare fore our mains to flucuate wildly hz wise.also check the platter is rotating freely without belt attached

[smg1965uk]

On the 33 setting I get a speed reading of between 33.8rpm and 40rpm
Sorry got the speed wrong, should be 'between 33.8rpm and 34rpm' doh!

[struth]

1 rpm isnt drastic.. you might hear it, most probably wont.. yes try a belt and check its free running with no belt, and not grinding noises

[smg1965uk]

No grinding from the motor, the unit seems near mint actually. I downloaded and printed a 50hz strobe sheet and found it very hard to judge, my eyes or the printing quality must be at fault, but did look fast. I also went a step further and drew a big arrow on a sheet of paper using software for pixel accuracy and printed that off. I taped it down and counted the revolutions with a stopwatch and got 34rpm also.

I'm gonna clean the platter and motor spindle with meths to clean off any crud from the old belt.

Thanks,
Steve

[walpurgis]

If it sounds OK, I'd not worry personally.

Belt and idler TTs are seldom spot on.

[smg1965uk]

I'm probably being a bit obsessive, probably due to growing up using my father's Garrard 401, will test again when I get the new belt hopefully tomorrow.

Thanks,
Steve

[walpurgis]

I've had several Thorens turntables and always found them nice sounding and never been aware of speed issues unless the belt was tired or dirty.

[Wakefield Turntables]

Make sure you buy an original Thorens belt. I've had two TD150's and I now own a TD160. Clean the inside of the platter is a good move. My current TD160 had a horrid black ring on the inner platter. Cleaning with meths improved speed stability by 0.1rpm, not much but I'm quite sensitive to pitch stability and I could tell. The biggest improvement came from belt replacement. Thakker belts are quite good and improve on platter speed stability I've noted bewteen a 0.1 to 0.3rpm improvement in platter stability in the three examples I've owned. The best belts IMHO are original Thorens and these seem to be the best for speed stability improvements. You may also want to get a cheap laser tachometer from ebay, you can get them now for <£30 with the ability to track speed stability to two decimal points, or failing that an app on your phone. Timing things with a stop watch isn't that accurate.

[walpurgis]

My current TD160 had a horrid black ring on the inner platter

They all get like that eventually if you don't keep them clean. Not just Thorens either.

[struth]

im saying nowt :eyebrows:

anyway as i said 1 rev a min isnt much to worry about unless you can hear it

[smg1965uk]

Make sure you buy an original Thorens belt. I've had two TD150's and I now own a TD160. Clean the inside of the platter is a good move. My current TD160 had a horrid black ring on the inner platter. Cleaning with meths improved speed stability by 0.1rpm, not much but I'm quite sensitive to pitch stability and I could tell. The biggest improvement came from belt replacement. Thakker belts are quite good and improve on platter speed stability I've noted bewteen a 0.1 to 0.3rpm improvement in platter stability in the three examples I've owned. The best belts IMHO are original Thorens and these seem to be the best for speed stability improvements. You may also want to get a cheap laser tachometer from ebay, you can get them now for <£30 with the ability to track speed stability to two decimal points, or failing that an app on your phone. Timing things with a stop watch isn't that accurate.

A Thakker belt is on the way, hopefully will test tomorrow.

Thanks,
Steve

[Wakefield Turntables]

You could always try and clean the belt you have. Try soaking it in mild warm water with some fairy liquid for 20-30 minutes and then gently pat it dry with paper towel. It may make some difference. I remember going bonkers when I tried to figure out the various variables which affect speed stability in these decks. It's usually the belt!

[trevisan22]

Hi, Are you checking with a record and the arm down

[walpurgis]

Hi, Are you checking with a record and the arm down

Good point.

[smg1965uk]

Hi, Are you checking with a record and the arm down

That is a good point. Recently acquired the deck without an arm and considered whether that drag would affect it that much. A friend had already showed me the app and the reading was the same either way, though his was a direct drive turntable.

[Barry]

You could always try and clean the belt you have. Try soaking it in mild warm water with some fairy liquid for 20-30 minutes and then gently pat it dry with paper towel. It may make some difference. I remember going bonkers when I tried to figure out the various variables which affect speed stability in these decks. It's usually the belt!

I would also lightly dust it with talcum powder. I would also concur that it is best to get an original Thorens belt rather than a Thakker alternative (I replaced the belt on one of my TD124s with a Thakker and after only a couple of months it had stretched.)

[Barry]

There is littlepoint in trying to achieve an absolute speed accuracy of better than 0.1%. The 'just noticable difference' in pitch depends on the pitch and on the waveform: for sine waves < 500Hz it is 3Hz, or 0.6%; for tones > 1,000Hz it is 0.1% for non-sinusoidal waveforms and 0.6% for sine waves.

However it is important to try to limit the speed stability (wow and flutter) to better than 0.1%.

[smg1965uk]

Thakker belt arrived and is about 2.5cm visually smaller.
Fitted it and along with cleaning the belt contact areas the speed test give me an average of 33.48rpm, bit of a difference from 34rpm.

You'd think a looser belt with cruddy contact points would be slower!

[walpurgis]

And it will be marginally slower when a record is being played. Hopefully about right.

[Jac Hawk]

On a belt drive the drag caused by the stylus dose have an effect with an app you want to get it to about 33.38, that 0.05 is approximately how much the TT is slowed down by drag