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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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22nd Nov 2017, 6:39 pm | #1 |
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BSR P128R speed/rpm
Hey,
So, long story short, I have this BSR P128R and the problem is that it spins too fast, jup, you read it right too FAST. I even can hear it, and iOS app "RPM" shows 35.46. And yes, I have cleaned it, rubbed, kissed etc. And yes, I have tried that screw, and that APP on other turntables. So, is there any solution? P.S. Sorry, for my English, not my native language. P.S.S Lubrication? Any suggestions? Product name? |
22nd Nov 2017, 7:17 pm | #2 |
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Re: BSR p128r speed/rpm
There is usually about a 5-7% speed variation on mid-range basic turntables such as the BSR P128.
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22nd Nov 2017, 8:47 pm | #3 |
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Re: BSR p128r speed/rpm
Deposits can build up on the stepped pulley on the motor that drives the idler wheel. Make sure the surfaces of the stepped pulley are clean.
Check the height of the idler wheel and stepped pulley to confirm they are running on the correct step and not touching the next step on the shaft.
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Frank |
22nd Nov 2017, 9:50 pm | #4 |
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Re: BSR P128R speed/rpm
Hey,
But I can hear that is too fast. And I did all the cleaning and stuff. |
22nd Nov 2017, 10:22 pm | #5 |
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Re: BSR P128R speed/rpm
Hey,
Thanks for replying. But 5% 7% is no good because I can hear it. Pink Floyd sounds funky, and in not a good way. And I did all the cleaning and stuff. And did all the positioning n stuff. I can adjust it (rubber wheel) 0.somthing/rpm. But not by -2/rpm. Possibly, something wrong with the motor or something like that? |
22nd Nov 2017, 11:06 pm | #6 |
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Re: BSR P128R speed/rpm
If it is all clean and the idler wheel/ stepped pulley is in alignment then the speed is set by the frequency of the power supply which should be 50Hz from your power provider, have you checked that?
As Edward states, they are not the most exacting turntables, but ususally very satisfactory.
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22nd Nov 2017, 11:26 pm | #7 |
Octode
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Re: BSR P128R speed/rpm
I used to have an MP60 (very similar to the P128 if not identical) which ran around 3% fast. That's just the way it was made.
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23rd Nov 2017, 12:39 am | #8 |
Nonode
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Re: BSR P128R speed/rpm
Surely not 5 - 7% out?! There is some basic engineering going on here isn't there? I have resurrected a lot of old autos - I have never found one that far out that wasn't faulty.
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23rd Nov 2017, 12:53 am | #9 |
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Re: BSR P128R speed/rpm
It does seem a bit extreme, but these are not hifi devices and people are much more aware of speed errors today after 30+ years of mass market compact discs. It may just be a particularly bad example. Lubrication issues tend to make decks run more slowly if anything.
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23rd Nov 2017, 1:10 am | #10 |
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Re: BSR P128R speed/rpm
As already advised - have you checked the frequency your deck is made to operate on with the frequency of your local mains supply in your country?
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23rd Nov 2017, 9:01 am | #11 |
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Re: BSR P128R speed/rpm
Is it a possiblity that the stepped pulley was made for a another deck with a turntable friction rim diameter of different size.
Initially I was thinking that all the parts were original but that may not be the case.
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23rd Nov 2017, 9:06 am | #12 |
Hexode
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Re: BSR P128R speed/rpm
Did the BSR P128R have a synchronous motor? The USA equivalent record changer model did, of the permanent magnet rotor design patented by Garrard and licensed to others like Dual and BSR.
If the motor pulley for a NONsynchronous motor were substituted, the speed would be substantially too fast. Or if a synchronous motor were used as a repair part for a NONsynchronous type, and the turntable's original motor pulley were used...same result. The P128R has entry-level hi-fi qualifications. It should not be running that fast. |
23rd Nov 2017, 9:08 am | #13 |
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Re: BSR P128R speed/rpm
jup, I have checked
https://gyazo.com/1c0fa8548505057796586f8e067c3cdc Don't get me wrong I understand that it's old and not the best TT out there but it does not mean that I can't fix it and enjoy/listen few records. |
23rd Nov 2017, 9:45 am | #14 |
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Re: BSR P128R speed/rpm
AFAIK all BSR (and, for that matter, Garrard) autochangers, other than those made for battery operation, use a shaded pole synchronous motor. For the UK market these would have been designed to run from 230-250vAC @ 50Hz, but, for continental Europe I would have thought they were designed for use on 220vAC, presumably also @ 50Hz, although I know that in some European Countries 110-120vAC was used in the past. All that having been said, I would expect a motor made for 240vAC to run, if anything, slower, if supplied with 220v, if, inded there was any noticeable variation at all. As ever, picture(s) showing clearly the motor and pulley(spindle)fitted will help us to help the OP
Last edited by 'LIVEWIRE?'; 23rd Nov 2017 at 9:47 am. Reason: to add further info. |
23rd Nov 2017, 10:44 am | #15 |
Octode
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Re: BSR P128R speed/rpm
I have come across this very very occasionally, so I have got my small flat modelling file and turned down the pulley on the motor and when I have got close to the required speed finished it off with fine wet and dry paper wrapped around a circular knob
The pulley being brass it cuts easily you need a steady hand and some patience to go down this path. Best of luck Gary |
23rd Nov 2017, 11:22 am | #16 |
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Re: BSR P128R speed/rpm
Jup, this helped, I did it with fine sand paper, some more cleaning an lubricating.
Thanks to all of you! Much Love! |
23rd Nov 2017, 1:12 pm | #17 | |
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Re: BSR P128R speed/rpm
Quote:
A synchronous motor's speed is absolutely set by the mains frequency until the stall point is reached, but a shaded pole induction motor always runs slower than synchronous speed, how much so depending on load. The more "slip" the more torque available (up to the stall point). Hence the uncertainty about the actual speed of the motor in basic decks.
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23rd Nov 2017, 1:22 pm | #18 |
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Re: BSR P128R speed/rpm
Are there similar speed errors on speeds other than 33.33 rpm?
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23rd Nov 2017, 1:26 pm | #19 |
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Re: BSR P128R speed/rpm
Yes, on all speeds it was 2rpm too fast.
But now it's all good. |
23rd Nov 2017, 4:13 pm | #20 |
Hexode
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Re: BSR P128R speed/rpm
I have used the file method in the past as well. I once filed down a fatter spindle from a UA25 to fit a C109 deck. It took forever and I only did 33 and 45 RPM. Glad that it's worked for you.
As has been said, these weren't precision items and some variation is common. I expect it's more the plastic platter that isn't precise rather than the spindle. People tended to notice more if the speed was too slow. Back in those days I can clearly remember hits of the day being played slightly fast on BBC Radio 1, leading me to believe my old record player was running slow. If you want it spot on you can download a strobe disc online and use that with a 50Hz lamp. Be careful not to take too much off though. |