boreas
"If it sounds good, it IS good." E.K.E.
As I and several others have said, this has no effect on the speed whatsoever. Having the idler restored or replaced would be a waste of time and money.
John
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Idler table tad faster by design.
- Thread starter Metalownz
- Start date
As I and several others have said, this has no effect on the speed whatsoever. Having the idler restored or replaced would be a waste of time and money.
John
Metalownz
Audiophile? Getting there
Too bad i can't figure out the problem. Guess ill just have to ride it high on the pulley/capstan to keep 33/3 speed and just live with it.
boreas
"If it sounds good, it IS good." E.K.E.
Since the steps on the capstan aren't tapered, I don't understand how changing the point of contact between capstan and idler will change the speed. The only way I know of to fine tune the speed would be to turn the capstan down.
How accurate is the speed on 45 and 78?
Metalownz
Audiophile? Getting there
Trust me it does. With the idler riding high on the capstan speed gets down to 33.3. Towards the bottom of the capstan speed increases. Same with 45 and 78. Runs perfect at the tops of each steps but fast on the bottom of each step. Im stumped just as much as the rest of you are.
boreas
"If it sounds good, it IS good." E.K.E.
I don't think so. I think that's just so that you can adjust the amount of pressure the idler exerts on the capstan. Insufficient pressure would cause slippage but increased pressure wouldn't make it speed up.
John
boreas
"If it sounds good, it IS good." E.K.E.
I trust you. I just don't see how that could happen unless there is a slight reduction in the diameter of the steps as you get nearer the top. Do you have a Vernier caliper?
Metalownz
Audiophile? Getting there
Uh oh. According to the manual the red capstan is the right one the 60 hz, and the blue is the 50 hz. I may have the blue one. Just cleaned the capstan again and look at this?! And im using a yellow brillo pad.
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number13
Well-Known Member
I work on idler drive tables all the time (FOUR on the work bench this week!) and this one has me stumped.
It sounds as if you found a table with very little use on it. Is that true? If so, try running the table for a few hours,
it just may need a bit of breaking in? Also, have you measured the speed while playing a record? Since these machines
are from a certain time when tone arms were huge and heavy it may well be that it is tuned a bit fast
to account for the drag of the period arm. That's all I got, hope you can get it sorted!
It sounds as if you found a table with very little use on it. Is that true? If so, try running the table for a few hours,
it just may need a bit of breaking in? Also, have you measured the speed while playing a record? Since these machines
are from a certain time when tone arms were huge and heavy it may well be that it is tuned a bit fast
to account for the drag of the period arm. That's all I got, hope you can get it sorted!
Metalownz
Audiophile? Getting there
Thats what i figured too, that if i run it close to the top that it wont damage the idler. Thank you very much for all your replies and helping out John.
Metalownz
Audiophile? Getting there
Thank you for responding. Yes, this table saw very little use. You can tell by looking at it that it was well cared for. You may be right.
Attachments
biscuithead
Me likes the eargasm retroplasm...
Good luck man... You have had a ton of replies, and they all amount to "hmm...I don't know" . If you ever get it figured out let us know.
One last tidbit: If you decide you want a new idler wheel, or if you want a sacrificial capstan ( this guy calls them "speed spindle motor shafts") for turning down or customizing. I've used this source:
http://www.kenselectronics.com/lists/phonodrive.htm
One last tidbit: If you decide you want a new idler wheel, or if you want a sacrificial capstan ( this guy calls them "speed spindle motor shafts") for turning down or customizing. I've used this source:
http://www.kenselectronics.com/lists/phonodrive.htm
Metalownz
Audiophile? Getting there
So you've worked on lots of idler drive tables and never seen this before? Then it has to be mostly on Pioneer idler tables because there is another gentleman Mfrench who has the same issue as me. Still trying to figure it out. Thank you for the link.
mfrench
Addicted Member
It could be, as I jokingly referred to, the Rega of idlers. But, no joking now. It might be that simple.
Regas are known for running fast. Its suggested by Rega(?) that it gives the music a bit of a pop.
I didn't like that in my Rega that I had, briefly. People said that I could spend nearly what the deck cost (mine was new) to fix it, with aftermarket bits and pieces. I had no interest in that. So off it went.
I'm not a musician, and have never noticed an issue with off-speed with the Pioneer. I asked my wife about it (its her deck now), and she said that she never noticed it, and shrugged. She was raised by a musician, with considerable training in her youth.
This might sound a bit odd, but, you might try a bit of heat-shrink around the steps, and see if it changes the speed to an acceptable degree. I did this quite a bit when I was redesigning an idler drive to my own specs, in early ciphering' stages. Its temporary and removable.
My latest experiments in this regard were heat-shrinking the pulley of a Rek-O-Kut belt drive that I'm considering customizing from a belt drive, to an external rim-drive idler.
You can also wrap the idler wheel in a produce rubber band. The ones that they use for broccoli bunches, for example. This might prove/disprove the laws of idler physics, to your satisfaction, regarding whether a different size idler wheel will make a diff.
Regas are known for running fast. Its suggested by Rega(?) that it gives the music a bit of a pop.
I didn't like that in my Rega that I had, briefly. People said that I could spend nearly what the deck cost (mine was new) to fix it, with aftermarket bits and pieces. I had no interest in that. So off it went.
I'm not a musician, and have never noticed an issue with off-speed with the Pioneer. I asked my wife about it (its her deck now), and she said that she never noticed it, and shrugged. She was raised by a musician, with considerable training in her youth.
This might sound a bit odd, but, you might try a bit of heat-shrink around the steps, and see if it changes the speed to an acceptable degree. I did this quite a bit when I was redesigning an idler drive to my own specs, in early ciphering' stages. Its temporary and removable.
My latest experiments in this regard were heat-shrinking the pulley of a Rek-O-Kut belt drive that I'm considering customizing from a belt drive, to an external rim-drive idler.
You can also wrap the idler wheel in a produce rubber band. The ones that they use for broccoli bunches, for example. This might prove/disprove the laws of idler physics, to your satisfaction, regarding whether a different size idler wheel will make a diff.
Metalownz
Audiophile? Getting there
When my Pioneer PL-41 ran fast it was a matter of finding out why. It was all a matter of having the right thickness of belt. Im determined ill solve the mystery.
boreas
"If it sounds good, it IS good." E.K.E.
That will indeed change the speed but it will increase it. Metal wants to decrease the platter speed.
Increasing the size of the drive element in the train (capstan) increases the rotational speed of the driven element (platter). On the other hand, decreasing the size of the driven element increases its speed. The size of the idler is immaterial as far as speed is concerned. Decreasing its size will indeed increase its rotational speed but the resulting decrease in its circumference means that it imparts less rotation to the platter. The two things, increased idler speed vs. decreased idler circumference, exactly offset each other, resulting in no change in platter speed.
John
bangsezmax
Turntable Whisperer
I work on idler drive decks on a daily basis. I'm going to throw out some info based on my experiences that haven't been touched on this thread.
1 -- It's a known issue that some early Pioneer motors got faster with age. Google "Pioneer PL-50 speed" and see what you get. They ALL apparently start running fast after a while. Now the PL-50 is a belt drive, but they may have (probably?) been using the same source for motors. Why do these motors start going faster? Nobody has been yet able to figure that out, nor has anyone found a proper fix for the motor. It's not caps or anything else in the AC chain. In the case of the PL-50, the best acknowledged fix is to wrap electrical tape around the platter to increase the diameter of the platter. One could also file the motor pulley (yes, pulley) to decrease the diameter of said pulley, but it would have to be a pretty drastic adjustment, so most people just go the tape route.
2 -- As boreas stated, getting a newly rebuilt idler probably isn't going to improve the situation. From the pics, your idler looks nice, and the pulley is clean (note that rubber buildup on pulleys is a prime culprit in fast operation on idler decks). Running your idler up near the top where it's not making full contact on the pulley will reduce overall torque and will mostl likely slow things down a touch. The downside is you're more likely to get pitch fluctuations, although these may not be audible.
3 -- If, as it appears, you have the capability of raising/lowering the position of the idler in relation to the pulley, I would have zero hesitation in getting out my file and starting to reduce the pulley diameter. Why, you may ask? If you look at the Dual idler drive pulley with adjustable speeds, they are tapered:
The way the pitch control works on these is that the idler moves up and down the pulley to get to different speeds. Why not just replicate this on the Pioneer? File just the top of the pulley to create a taper. Then adjust the idler wheel to the correct spot and Bob's your uncle.
When we're talking idler drive units that are 40+ years old, we're often in the realm of creative solutions. I spend a good deal of time decreasing (via filing) or increasing (via a solution of nitrocellulose in butyl acetate, a.k.a. clear nail polish) the diameters of motor pulleys. This is how it's done in this game if you want to be on pitch (and I'm a musician as well as a repairman and I really, really like proper pitch).
A few other things to note from the thread: I usually get rebuilt idlers when they get rock hard (no torque and usually noisy), floppy soft (no torque -- Garrard's are notorious for this), or get noisy bumps in them from being up against the pulley for decades. If your idler has good torque and isn't noisy, it's probably okay. You might want to sand the edges to freshen it up.
And BSRs -- they were fast when they were brand new. Don't ask me why, they just were. The nicer ones work well with the taper trick. They'll have an idler positioning screw right there on the bearing assembly, easy peasy.
1 -- It's a known issue that some early Pioneer motors got faster with age. Google "Pioneer PL-50 speed" and see what you get. They ALL apparently start running fast after a while. Now the PL-50 is a belt drive, but they may have (probably?) been using the same source for motors. Why do these motors start going faster? Nobody has been yet able to figure that out, nor has anyone found a proper fix for the motor. It's not caps or anything else in the AC chain. In the case of the PL-50, the best acknowledged fix is to wrap electrical tape around the platter to increase the diameter of the platter. One could also file the motor pulley (yes, pulley) to decrease the diameter of said pulley, but it would have to be a pretty drastic adjustment, so most people just go the tape route.
2 -- As boreas stated, getting a newly rebuilt idler probably isn't going to improve the situation. From the pics, your idler looks nice, and the pulley is clean (note that rubber buildup on pulleys is a prime culprit in fast operation on idler decks). Running your idler up near the top where it's not making full contact on the pulley will reduce overall torque and will mostl likely slow things down a touch. The downside is you're more likely to get pitch fluctuations, although these may not be audible.
3 -- If, as it appears, you have the capability of raising/lowering the position of the idler in relation to the pulley, I would have zero hesitation in getting out my file and starting to reduce the pulley diameter. Why, you may ask? If you look at the Dual idler drive pulley with adjustable speeds, they are tapered:
The way the pitch control works on these is that the idler moves up and down the pulley to get to different speeds. Why not just replicate this on the Pioneer? File just the top of the pulley to create a taper. Then adjust the idler wheel to the correct spot and Bob's your uncle.
When we're talking idler drive units that are 40+ years old, we're often in the realm of creative solutions. I spend a good deal of time decreasing (via filing) or increasing (via a solution of nitrocellulose in butyl acetate, a.k.a. clear nail polish) the diameters of motor pulleys. This is how it's done in this game if you want to be on pitch (and I'm a musician as well as a repairman and I really, really like proper pitch).
A few other things to note from the thread: I usually get rebuilt idlers when they get rock hard (no torque and usually noisy), floppy soft (no torque -- Garrard's are notorious for this), or get noisy bumps in them from being up against the pulley for decades. If your idler has good torque and isn't noisy, it's probably okay. You might want to sand the edges to freshen it up.
And BSRs -- they were fast when they were brand new. Don't ask me why, they just were. The nicer ones work well with the taper trick. They'll have an idler positioning screw right there on the bearing assembly, easy peasy.