How to reduce turntable WOW..?

[MisterDK]

I’m presently getting an old idler drive turntable sorted and using a phone app to check RPM and WOW.
On this table, speed is OK but I think WOW seems a little high and I’d like to see it lower. I haven’t played with platter bearing oil viscosity yet (and this has a large bearing). I’m assuming that the app is somewhat accurate but don’t know - and it’s all I’ve used on this table, so far. I haven’t actually listened to the table in my system yet.

Just wondering if there are any tried and true methods people have used to reduce wow.
And, while this is an idler, might similar wow reduction methods work on belt tables?

Results from the table I’m working on:

 

[T68]

Besides working on the platter bearing you mentioned, one thing to look for may be that the motor/pulley and idler wheel are straight. On old garrard idlers (the auto slim models I think) the idler mount can develop a lean (probably caused by users mounting platter without retracting the idler and therefore hitting it and bending the bracket).

Sagging motor mounts making the motor and pulley lean can also cause speed instability.

Then you got the classic stuff: keeping the pulley, idler and platter inside really clean.

And oh, of course having a serviced motor with cleaned and relubed bearing.

Good luck

 

[Montycat]

I'm sceptical of how accurate the apps are especially with respect to wow. If the accelerometer (I think that's the sensor it relies on) is not perfectly calibrated and positioned in the center of the platter will it measure accurately?

 

[tabarddn51]

Hi, What T/T is it you are getting. The original specs, (check on V/Engine) may mean that it high speed problems even at the start of it's life!!

Cheers

 

[WaynerN]

If the table has been in storage, there may be a flat spot on the wheel.

 

[RDW]

I'm sceptical of how accurate the apps are especially with respect to wow. If the accelerometer (I think that's the sensor it relies on) is not perfectly calibrated and positioned in the center of the platter will it measure accurately?

I use the iPhone RPM app and the wow measurements don’t make any sense at all. I would not put any stock in the results from the app. I downloaded a different app and the results were just as bad. This is on 3 turntables that I know are better than the apps report. The 33rpm reading shown is similar to that reported for a brand new Fluance RT82.

 

[kirk57]

Try leaving the Russco on overnight and measure again.

I’ve found that all types of turntables benefit from this, assuming of course there are no truly worn out parts that might get worse.

 

[likebike23]

What exactly have you done? Motor cleaned and lubed? Idler soft and pliable? I've soaked rock hard idlers in DOT3 brake fluid with great results. Platter bearing cleaned and lubed? Idler roller bushing and shaft cleaned and lubed? Motor pulley and platter rim cleaned?

 

[MisterDK]

Hey gang, the table in question is a ‘70s Russco Studio-Pro. The idler wheel is a new one made of Delrin, with a square section O-ring tire - it’s not old and hard. The motor is clean and lubed.
Once I get a plinth made for this one, I’ll concentrate more on fine tuning for a lower wow reading - I’ll keep you posted.

A picture of the table I’m working with:

 

[mfrench]

Wow!

(in response to how to reduce the Wow(s))

 

[adnick]

Wow!

(in response to how to reduce the Wow(s))

I’ll second that Wow! It just keeps climbing

 

[mfrench]

I’ll second that Wow! It just keeps climbing

Ya know, when you show the things off, folks are likely to say, Wow.


<just kidding!>

 

[likebike23]

Hey gang, the table in question is a ‘70s Russco Studio-Pro. The idler wheel is a new one made of Delrin, with a square section O-ring tire - it’s not old and hard. The motor is clean and lubed.
Once I get a plinth made for this one, I’ll concentrate more on fine tuning for a lower wow reading - I’ll keep you posted.

A picture of the table I’m working with:

View attachment 2665780
View attachment 2665776

I'll give that a wow!!! also.

 

[likebike23]

What did you expect would happen with a table that has so much Wow factor?

 

[BillWojo]

That cleaned up very nicely. Looks great with that tonearm.
Make certain that the idler wheel isn't canted in any way in relationship to the platter. Also make sure that these is no end play on the idler wheel, even a minuscule alignment issue could have the idler racing back and forth using up the end play. Better to have the idler wheel spin free with no play. Let it ride against the washers and oil film.
As far as those turntable apps, it's time for someone with good testing equipment to evaluate them. A full report on both the apps and a handful of popular phones would be awesome.

BillWojo

 

[BillWojo]

I forgot to add, I find after working on my Russco that when I first run it, it may make faint noise but that goes away after a few hours of just leaving it on. After that it's always quiet. Not sure why that is, it's usually after having the main bearing out for adjustment and after I replace it I need to adjust the idler tension.
For others, the way I adjust the idler tension is to back it off completely and advanced the idler until it starts to spin the platter. Use a finger to gauge if it's slipping. You shoot for just enough pressure to smartly spin the platter up to speed but no more.
On the Russco turntables that is set with a separate screw for both 33 and 45 and they are located in the little holes on the shifter gate plate.

BillWojo

 

[MisterDK]

That cleaned up very nicely. Looks great with that tonearm…

Thanks; it did clean up pretty well, I think. Ignore the goofy green mat. I just cut that out of craft foam to set a record on it and watch it go ‘round..

Got started on my plinth today. I’ll post pics on my Russco thread when I’m a little further along with it.

 

[adnick]

Thanks; it did clean up pretty well, I think. Ignore the goofy green mat. I just cut that out of craft foam to set a record on it and watch it go ‘round..

Got started on my plinth today. I’ll post pics on my Russco thread when I’m a little further along with it.

It’s a really beautiful machine, and the tonearm just adds to the looks

Red or dark blue mat would look fantastic, had a deer skin that molded to the platter perfectly without glue.

Looking forward to the plinth design/build

Andy

 

[adnick]

I forgot to add, I find after working on my Russco that when I first run it, it may make faint noise but that goes away after a few hours of just leaving it on. After that it's always quiet. Not sure why that is, it's usually after having the main bearing out for adjustment and after I replace it I need to adjust the idler tension.
For others, the way I adjust the idler tension is to back it off completely and advanced the idler until it starts to spin the platter. Use a finger to gauge if it's slipping. You shoot for just enough pressure to smartly spin the platter up to speed but no more.
On the Russco turntables that is set with a separate screw for both 33 and 45 and they are located in the little holes on the shifter gate plate.

BillWojo

Interesting that my old Russco is extremely quiet, and Bill is right about the idler & assembly. Oil viscosity and platter height adjustments changed the behavior with my table. I’m running Teflon washers at the top and bottom of the idler shaft.

These tables are truly sleepers, there are those that know how good they are, but it’s not common knowledge, yet

 

[adnick]

You also stating the factory tonearm is also a sleeper?

These tables are like most of the high end broadcast turntables of the era, most were sold with the tonearm as an optional choice (variety of vendors), not just their own. In fact it’s rare to find a Russco tonearm, and wouldn’t consider it anything special.

ROK had much better company tonearms, they also were sold as an option on many different tables, ROK arms themselves were successfully marketed as an individual item.



VR

Andy