Rega Turntable on/off switch making electrical popping noise

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My Rega P5 turntable makes an electrical popping noise whenever using the turntable on/off switch. I noticed the noise happens more frequently when switching off. I've looked around on forums and it seems that is not an uncommon problem.

I like a solution to eliminate the noise as is very irritating when listening on headphones and also sometimes causes my phono preamp to go unstable generating low level motor boating noise.

Also my turntable is powered by the Rega TT-PSU which I believe generates AC and DC power to the 24V motor.

Can anyone please help?
 
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Suppression

The popping noise is caused by the contacts on your switch arcing, so you need to add a suppression capacitor across the switch contacts (when the switch is off the suppression cap needs to go across the non powered side).

This should cure your noise problems, this is done on most electrical equipment across the single pole or double pole mains switches also (FYI).
 
The arcing always occurs at switch off, but can be suppressed.

Here's a simple RC snubber. Typical values are R = 100 ohm and C = 100nF

It suits both ac and dc conditions, and is commonly used with electric motors.
 

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Have you opened the psu yet I have looked online & noticed the TT PSU is powered by a 24v supply, so which switch are you pressing the mains power switch to the transformer to switch the TT off ?

I use the black round switch on the turntable plinth, and the Rega TT-PSU is left powered on continuously.

I'm sorry I forgot to add there's only 24V on the switch.
 
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In case you weren't aware the Rega TT-PSU generates a clean sine wave and from the manual it describes it also generates AC and DC power. It is because of this it complicates matters for me wanted people opinion switching noise could still be suppressed wouldn't have adverse effect on the turntable performance.

This is the TT-PSU manual http://www.rega.co.uk/uploads/ttpsu-2011-english-manual.pdf
 
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I use the black round switch on the turntable plinth, and the Rega TT-PSU is left powered on continuously.

I'm sorry I forgot to add there's only 24V on the switch.

Yes I remember now it's just a 24vac motor & the psu changes voltage for 33 / 45 rpm.

You don't need anything like an RC Snubber that's for switch mode supplys & unnecessary, just use a .1uF 100v cap across the contacts, since its only 24v just use a film/polyester cap types.

? You did not say also if it is a single pole or double pole switch ?
 
I don't know until I disassemble the switch. If it is a double pole, would that mean each pole will need a separate capacitor across it?

Either way you only need 1 cap.

If single pole the cap sits on both input & output lugs which will supress just before the switch makes it short circuit across the cap to supply power.

If double pole you just put the 1 cap across the wires going to the motor to supress & smooth.

You may already have a suppressor in their that is connected if so replace it & replace the switch as contacts may be burnt out if suppression has failed & should not cost you much, post a photo of the switch when disassembled as may be a common switch ?

Cheers

J247W
 
I know this is an old thread, but just in case others are having this problem the work around is simple.

Leave the Rega rocker switch on the plinth in the 'ON' position and just use the on/off button on the TTPSU to turn On/Off

No need for two switches when just one will do the job.
 
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