AC Michell Orbe wow & flutter

[Harrybob]

Hello,

Does anyone what sort of wow and flutter reading I should expect on an older AC motor Michell Orbe with QC psu ?

Thanks

Alun

[wumpling]

Not measured mine but with the qc having a crystal based frequency generator I would look at the motor or bearing lubrication if you're getting audible problems.

[Harrybob]

I am worried it may be the motor, although i have had it serviced by Michell. The strange thing is its worse with new belts (i have tried two brand new genuine Michell belts) and im getting readings of around .5% using RPM. With the old belt that came with the Orbe it goes down to around to between .15 and .20%. Still not amazing though.

[wumpling]

I read somewhere that reversing the belt may help as imperfections on the surface of the belt can cause speed irregularities as they enter the pulley on the motor. Seems odd to me as the belts aren't marked in any way.

[Harrybob]

Yeah i heard that too, and have tried it. Seems to have an effect moreso on the old belt. The new belts seem a lot smoother.

[blake]

Michell has a very serious problem with the new belts. They are simply not very good, although they were literally atrocious and unusable a few years ago, at least with my original AC motor and pulley.

I'm a long term Michell owner (about 33 years) with an AC motor as well. The newer belts supposedly fare better with, and may be usable with the DC motor according to someone in the UK that I've had correspondence with who has done very extensive measuring on the older belts and the newer version.

But even a very well worn original version Michell belt is likely to give better results on an AC motor than the newer Michell belts I believe.

I'm recycling through the 4 original versions I have right now hoping that Michell will continue to work on this to source a belt that is closer to the original in performance.

I've tried a few non Michell belts as well and not totally convinced of their quality with the AC motor either.

[Harrybob]

Thanks for the info, thats very interesting. Perhaps my motor is ok after all. Were any of the after market belts better performers than the Michell ones ?

[flapland]

There are a few measurements on RPM iPhone app which now has a database of real life measurements. The Orbe's on that list had a w/f measurement of .14 or .09 which appears to be better average across a range of turntables. My SME 20/2 is .18 for example.

How true is the pulley as it could be off centre. Easy to check but a pain to correct.

[wumpling]

Have you tried rotating the ball in the main bearing so the the contact area is changed? Logic would suggest that if the ball wears in one place then contact area may increase so changing to a new area should reduce friction.

[Harrybob]

Hi there, yes i have put a new ball bearing in, no difference ☹️

[wumpling]

Sorry, running out of ideas.

[Harrybob]

Perhaps it is the case that tge newer belts are a problem with the older motors. I need to try and obtain some more older belts to try out.

[Harrybob]

I have just given the old belt a really good clean and this has produced a marked improvement in W&F readings. It looks as if it’s definitely all about the belts. What a shame the new belts aren’t suited to the older decks. :(

[blake]

Thanks for the info, thats very interesting. Perhaps my motor is ok after all. Were any of the after market belts better performers than the Michell ones ?

I've used the Malvern Hills belts from Ebay and also some that I sourced from Germany (they are slightly different than the Malvern Hills-definitely not the same and I don't see them listed on Ebay now). I haven't done what I would consider really accurate measurements but the Michell owner I corresponded with in the UK tried the German belt on my recommendation and found that it did not perform/measure as well as the older Michell belts he had on hand.

To be fair, he did get back to me and say that the newer Michell belt did seem to work well enough on his DC motor after he let it run in substantially; interestingly it did not fare well out of the box.

Sonically, I still prefer the original Michell belts to any of the newer non-OEM belts and the new Michell belts with my AC motor.

If you find a source for any of the original belts, please let me know. I would definitely purchase a few.

How did you clean the older belts?

[DSJR]

The one good thing hopefully, is that Michell have a decades-long reputation for good customer care, so hopefully they'll sort it. For a few years very early on, the Gyro began using twin belts to fix a pronounced wow problem as reported in the early to mid 80's HiFi Choice review books, although by the time I came by them again in the later 90's, they'd gone back to a single one. Some people are more susceptible to the wow on many belt driven decks too, but in my case, it took digital and the best idler models to show it to these ears.

Good luck. Maybe there are other turntables that use a similar length band or cord that might work? I take it that running the deck for a few hours to spread any elastic loading around the belt doesn't help this issue?

[Harrybob]

I've used the Malvern Hills belts from Ebay and also some that I sourced from Germany (they are slightly different than the Malvern Hills-definitely not the same and I don't see them listed on Ebay now). I haven't done what I would consider really accurate measurements but the Michell owner I corresponded with in the UK tried the German belt on my recommendation and found that it did not perform/measure as well as the older Michell belts he had on hand.

To be fair, he did get back to me and say that the newer Michell belt did seem to work well enough on his DC motor after he let it run in substantially; interestingly it did not fare well out of the box.

Sonically, I still prefer the original Michell belts to any of the newer non-OEM belts and the new Michell belts with my AC motor.

If you find a source for any of the original belts, please let me know. I would definitely purchase a few.

How did you clean the older belts?

Hi, just used isopropyl alcohol.

[Harrybob]

The one good thing hopefully, is that Michell have a decades-long reputation for good customer care, so hopefully they'll sort it. For a few years very early on, the Gyro began using twin belts to fix a pronounced wow problem as reported in the early to mid 80's HiFi Choice review books, although by the time I came by them again in the later 90's, they'd gone back to a single one. Some people are more susceptible to the wow on many belt driven decks too, but in my case, it took digital and the best idler models to show it to these ears.

Good luck. Maybe there are other turntables that use a similar length band or cord that might work? I take it that running the deck for a few hours to spread any elastic loading around the belt doesn't help this issue?

Hi there, yes i have tried running the new belts in over extended periods and whilst i have seen improvements it wasn’t nearly enough to make the belt useable. Has anyone spoken to Michell lately about this issue ?

[blake]

Hi there, yes i have tried running the new belts in over extended periods and whilst i have seen improvements it wasn’t nearly enough to make the belt useable. Has anyone spoken to Michell lately about this issue ?

Michell has been working on this problem for about 2 years now and it is, quite frankly a serious one as far as I'm concerned.

I haven't spoken with Michell directly as I'm in North America but I did have email correspondence with the North American distributor in the past few months and they acknowledged the new belts are not the same quality as the older/originals. All you have to do is listen to them (at least with the original AC motor) and it is painfully obvious. There must be more difficulty in sourcing than I can understand but I would like to think that Michell would make it a bit of a priority.

[Harrybob]

Michell has been working on this problem for about 2 years now and it is, quite frankly a serious one as far as I'm concerned.

I haven't spoken with Michell directly as I'm in North America but I did have email correspondence with the North American distributor in the past few months and they acknowledged the new belts are not the same quality as the older/originals. All you have to do is listen to them (at least with the original AC motor) and it is painfully obvious. There must be more difficulty in sourcing than I can understand but I would like to think that Michell would make it a bit of a priority.

Lets hope so, its an expensive upgrade to get a DC Orbe motor and controller :(

[matador]

Hi!
My Orbe with old AC motor and new belt shows ~0.13% Wow & Flutter on AnalogMagik All-In-One.
AnalogMagik's manual says: "A good setup should display a Wow & Flutter reading of below 0.2%. A very good setup should be below 0.1%."
Regards, Andrew.