Brought in a low volume Blues Deluxe for repair and servicing. Went straight to the Phase Inverter as every one of them that comes in the shop it seems, has an open 100k resistor. Sure enough. Replaced with 1/2w Carbon film. Volume restored. Replaced the existing filter caps with new F&T caps. Removed the original plastic input jacks, installed a Post Phase Inverter Master Volume, and repaired the torn 3 prong cord. Cleaned the 10 years worth of crud off the faceplate and replaced the washers and nuts with new. Much better! A lot of you may wonder why I put a PPIMV on a Blues Deluxe? Easy. It gives you the ability to fatten up the clean channel and get that edge of break up tone while still maintaining control of volume. I utilize a trainwreck style master on these instead of say a Lar Mar .