VOM #1245 record changer noise

Mark Laycock · by **Mark Laycock** » Sat Nov 24, 2007 12:38 am

Hi, I just bought a 1962 Motorola SK52W console in excellent condition. I had 7 tubes replaced and I serviced the changer plus the techs serviced it a little more and everything plays and sounds great. The only problem is that when the album is finished playing and the tonearm goes to lift up it make a very loud popping noise in my speakers as the needle leaves the vinyl. Now, i like to put a stack of records on at night when I go to bed and when this happens it makes us jump about a foot off the bed. Is there a way to stop this loud noise, maybe an adjustment or something? Thanks, Mark

Record-changer · by **Record-changer** » Mon Nov 26, 2007 12:21 am

That V-M changer either has no muting switch, or one that isn't working.

If the pop happens in only one channel, it might be a bad input capacitor causing the input amplifier to react to the muting switch closing.

If the pop is happening when the power shuts off instead, a .01 uF 600 V capacitor across the power switch will remove the pop and extend the life of the switch.

Mark Laycock · by **Mark Laycock** » Mon Nov 26, 2007 8:23 am

Hi Record Changer, Under further observation I believe the noise to be caused by the mute switch activating right before the needle lifts from the album and it's in both speakers and very loud. Is there some kind of filter capacitor that i can soldier to either the mute switch or one of the wires coming from the switch to remove the popping noise. Thanks, Mark

Record-changer · by **Record-changer** » Fri Nov 30, 2007 7:39 am

It's more likely the switch is activating too late.

Test this by activating the switch manually.

If it is the switch making the noise, it is either a fault in the amplifier, or you have an electret cartridge (rare).

Check the input capacitors on the amp. If they are passing DC, or are electrolytic capacitors, this is is the problem.

Another possibility is that the pickup is slowly generating static electricity as the record plays. This happens with ceramic and crystal pickups, but not magnetic ones.

Try connecting a 1 megohm resistor across each muting switch contact. This will drain off any charge build-up.

On a tube amp, this can happen if the grid leak resistor on the input tube fails.