How do I change pitch on my turntable ?

Paul Young

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Jan 14, 2015
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I've just inherited an old Aiwa PX-E850 which is working fine and is perfect for my limited ambitions of playing some old vinyl through my amplifier.

The one issue is that my 45rpm setting plays at 48rpm and it is noticable when listening. There is no pitch control on top of the unit but there is access to many screws under the platter and I suspect one of these adjusts the speed.

does anybody know which one does the job or what the screw might look like or where it might sit ?

Any help appreciated !
 

MajorFubar

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Mar 3, 2010
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Is it belt drive or direct drive? My old DD Technics SL6 has trimmers accessible through holes in the base for both 45rpm and 33.3rpm. Ideally you need a 50Hz strobe disc (easily downloadable) and access to a 50Hz light source such as a tungsten lamp
 

Paul Young

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Jan 14, 2015
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Its a belt drive. How would I identify those trimmers as there are several groups of screws accessible through holes ?
 

ifor

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Dec 3, 2002
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Paul Young said:
Its a belt drive. How would I identify those trimmers as there are several groups of screws accessible through holes ?
Wouldn't be worth replacing the belt with a new one?
 

The_Lhc

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Oct 16, 2008
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ifor said:
Paul Young said:
Its a belt drive. How would I identify those trimmers as there are several groups of screws accessible through holes ?
Wouldn't be worth replacing the belt with a new one?
I picked up a cheap Garrard GT20 the other week, that was playing slow and had a noticably saggy belt, replaced it with a new one, which is much tighter and it has improved things but not completely, it still plays a little slow, compared to my other TTs, not sure what I can do about that?
 

MajorFubar

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With a belt-drive turntable the different speeds are accomplished either mechanically by moving the drivebelt between two different-sized pulleys while the motor rotates at a constant speed, or it may be like a DD where the motor drives one pulley at two different speeds. Firstly you need to know which method your deck is using, and it's generally fairly obvious.

On decks where the motor speed is constant, there may be just one trimmer on the PCB to control its speed, or perhaps more likely, the motor itself will have a governor accessed through a hole in the rear, like the capstan motor in most cassette decks. Possibly there will be a hole in the base of the deck to gain access to the motor's governor or to the solitary trimmer on the PCB, but as likely as anything you will have to take the base off to gain access.

On decks where the motor-speed changes, the individual speeds are commonly set with two trimmers on the PCB which often are accessible through unmarked holes in the turntable base. A small LED torch shined down any suspicious-looking orifice in a darkened room is usually sufficient to spot them.
 

The_Lhc

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Oct 16, 2008
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MajorFubar said:
With a belt-drive turntable the different speeds are accomplished either mechanically by moving the drivebelt between two different-sized pulleys while the motor rotates at a constant speed, or it may be like a DD where the motor drives one pulley at two different speeds. Firstly you need to know which method your deck is using, and it's generally fairly obvious.

On decks where the motor speed is constant, there may be just one trimmer on the PCB to control its speed, or perhaps more likely, the motor itself will have a governor accessed through a hole in the rear, like the capstan motor in most cassette decks. Possibly there will be a hole in the base of the deck to gain access to the motor's governor or to the solitary trimmer on the PCB, but as likely as anything you will have to take the base off to gain access.

On decks where the motor-speed changes, the individual speeds are commonly set with two trimmers on the PCB which often are accessible through unmarked holes in the turntable base. A small LED torch shined down any suspicious-looking orifice in a darkened room is usually sufficient to spot them.
The Garrard is single speed with the belt being moved between two pulleys, I've had the base off and looked underneath, the motor appears to be an enclosed unit, didn't notice any holes but I'll have another look at the weekend and see what I can find, I didn't really trace the power lines anywhere, possibly the pots are elsewhere.
 

The_Lhc

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Oct 16, 2008
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The_Lhc said:
MajorFubar said:
On decks where the motor-speed changes, the individual speeds are commonly set with two trimmers on the PCB which often are accessible through unmarked holes in the turntable base. A small LED torch shined down any suspicious-looking orifice in a darkened room is usually sufficient to spot them.
The Garrard is single speed with the belt being moved between two pulleys, I've had the base off and looked underneath, the motor appears to be an enclosed unit, didn't notice any holes but I'll have another look at the weekend and see what I can find, I didn't really trace the power lines anywhere, possibly the pots are elsewhere.
That'll be a no then, the motor takes power straight from the mains, the only thing it goes through is the power switch, the motor has no speed adjustment. It could be explained if the motor was 60Hz instead of 50Hz but then I'd have thought the voltage would be wrong as well.

I suppose it would be possible to get an external speed controller?
 

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