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  #1  
Old 21st March 2006, 07:01 PM
I love my records I love my records is offline
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Default Speed accuracy on a Gyrodec

I seem to have a bit of a problem.

Last week, I was listening to an album and about 15 mins through side 1, I felt sure it had slowed down....when I listened carefully, it definitely had.

The other day, I put on Wish you were here, but the long chord intro was playing too slow. It's pitch was accurate, but it just wasn't spinning at the right speed. Three minutes into the chord and the LP suddenly went back to the correct speed. It was just like a switch had been flicked.

Now, I'm no expert, but I've tried to narrow down the causes.

1. Cleaned the belt, rim and pulley...spotless. Platter spins frely as well, for minutes.
2. Checked speed with a strobe.....BANG ON whenever I try it!
3. Looked inside the cheap power supply I got with it (1995 model)

Inside the power supply is a cheap transformer and a single 22microfarad cap.
The cap might be burned out as it smells a little and there is colouration around it's base and at the top (very slight)...or is this normal..?

Could this cap be the problem though? I thought the speed of the deck depended on the A/C frequency?

The only 'hunch' I've had is that the motor could be the problem, but why would it work for most of the time but go slow for a little bit..I notice it about once every 8 hours...do the brushes wear out or anything similar happen?

Help me, I'm really confused..
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Old 21st March 2006, 08:08 PM
dave dove dave dove is offline
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Default Re: Speed accuracy on a Gyrodec

no help
just a thought
if the pitch is accurate
the speed must be too
any change in speed
will affect pitch accordingly

dave
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  #3  
Old 21st March 2006, 08:16 PM
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Greg. Greg. is online now
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Default Re: Speed accuracy on a Gyrodec

I would suspect the power supply. It really is a cheap unit and it continues to surprise me that Michell are happy to sell their decks with this PSU. I believe Tony Moore identified when he first had his that the speed was not stable with this standard PSU and I would agree. Option is to upgrade, but that can be expensive as the HR is over £300 but does make a major upgrade world of difference which you'd not be dissapointed with. The other option is to make your own. I'll email you on this.

Best wishes,

Greg
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  #4  
Old 21st March 2006, 08:24 PM
I love my records I love my records is offline
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Default Re: Speed accuracy on a Gyrodec

Dave, I just meant that when slow, the pitch didn't waver about. Sorry about the confusion.
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Old 21st March 2006, 08:27 PM
I love my records I love my records is offline
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Default Re: Speed accuracy on a Gyrodec

Cheers greg, look forward to getting my iron hot again, it's been a very long time..


Dave
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  #6  
Old 22nd March 2006, 12:44 AM
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John T John T is offline
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Default Re: Speed accuracy on a Gyrodec

Quote:
Originally Posted by Greg.
it continues to surprise me that Michell are happy to sell their decks with this PSU.Greg
It's the age-long ploy called Marketing Greg! Get the punters in on the bottom of the ladder at not too much expense and then encourage them up the profitable "upgrade" path! Linn made an art of it!

Regards,

John.
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  #7  
Old 26th March 2006, 10:08 PM
novalves novalves is offline
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Default Re: Speed accuracy on a Gyrodec

I would just change the capacitor with a new one of the same value and type.
The cap takes time to provide a charge to the motor, it's heating up ........
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  #8  
Old 28th May 2006, 10:13 AM
kevchard kevchard is offline
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Default Re: Speed accuracy on a Gyrodec

Hi All
I was doing a search on the internet regarding a QC problem and came across your site.
Another site suggested if your motor was running slow, then place a small drop of fully synthetic motor old on the motor shaft, does this appear a good idea?
My QC was involved in an accident at home, and the speed switch broke as the unit fell of a shelf. I tried removing the old switch and replacing with a new one (i am skilled with a soldering iron), but the tracks got damaged upon removing the old one.
Would it be possible for you to email me the cct diagram to make a temp power supply as i save up for the dc motor and power supply upgrade for the gyrodec.
Thanks for your time in reading this.
Cheers
Kevin
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  #9  
Old 28th May 2006, 12:16 PM
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Default Re: Speed accuracy on a Gyrodec

Hi kevin,

Welcome. Unfortunately the DIY option I have for the PSU is for a DC motor only. I can't help with an alternative for the QC supply.

Best wishes,

Greg
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  #10  
Old 28th May 2006, 12:47 PM
kevchard kevchard is offline
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Default Re: Speed accuracy on a Gyrodec

Hi Greg
Thanks anyway.
Don't supose anyone has ever taken the standard a.c. power supply apart to see what it consists of?
I'll keep my fingers crossed that i can get the info i need.
Cheers
Kevin
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