Loud pop when I use the turntable on/off button

Montgomery,
This topic has been discussed here many, many times. Just do some search for an in-depth discussion regarding this issue.

In a nutshell, the culprit is your Classic; you'd need to replace a capacitor in the motor to get rid of the pop. Or you can simply lower the volume all the way down or switch the input before you turn off the turntable. That's what I do.

Actusreus is absolutely right.

Change the capacitor across the on-off switch from the .001 microfarad installed to a .01 microfarad. That is also the recommendation from VPI. Worked great in my system, thump instantly gone, now I can turn it on/off at any volume. Just unscrew the trap door under the on/off switch, the capacitor is across the on/off switch with screw on insulated electrical connectors. I found it easier to take the platter off and then tilt the turntable on it's side on the carpet against the couch with the trap door at the top. I emailed VPI and they actually sent me the capacitor, but you can get it at any radio shack for less than a $.