This is the reply I received from Mike at VPI in 2010 after I had this problem with my Classic 1. It completely fixed my thump.
VPI Customer Service
11/26/10
The pop is system dependent and since we have no idea what a customer has we install the cap that works 80% of the time. You need to change the on-off bypass cap to a .01 microfarad 400V non polarized cap. We usually install a .001.
Mike
VPI Customer Service
11/26/10
The pop is system dependent and since we have no idea what a customer has we install the cap that works 80% of the time. You need to change the on-off bypass cap to a .01 microfarad 400V non polarized cap. We usually install a .001.
Mike