Rega Turntable on/off switch making electrical popping noise

[spikeyw]

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?

[J247W]

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).

[spikeyw]

Thanks for your reply.


Would this work with the TT-PSU connected? Also this happens mainly when switching off, does arching still occurs?

[DF96]

Arcing is often worse when switching off. You can put a small X-rated cap either across the switch contacts, or across the PSU mains input.

[Galu]

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.

[Galu]

In the interests of technical accuracy, the site indicated below shows how to calculate the R and C values for a snubber. (Scroll down to near the bottom.)

How to pick the R and C values of a RC snubber (what are the most important equations) - Quora

[coolmaster]

Look for Class X1/Y2 film suppression capacitor 3300pf - 3900pf/300-400VAC. I've used this many times with success. Good luck!

[J247W]

Originally Posted by spikeyw

Thanks for your reply.


Would this work with the TT-PSU connected? Also this happens mainly when switching off, does arching still occurs?

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 ?

[spikeyw]

Originally Posted by J247W

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.

[spikeyw]

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-...ish-manual.pdf