Well, I'm about a year into trying to fix my old DR. It started with occasional "popping/crackling" but more the Paper Rustling sound. I don't get back to it often. There was another thread on it maybe a year ago which I cant find right now. Here's the latest: -I was working on another project so I left the DR on for at least 3 hours. Every once in a while it would start making noise but not much at all and not for long. When it started I noticed that If I turn the normal channel volume off it quit. But occasionally the reverb channel would do it to a lesser extent. -Last time I tried it was at rehearsal and it just got to crackling and hissing too much to use. Maybe sitting just "on" without playing isn't a good test? -I noticed that both V1 and V2 are slightly microphonic when tapped with a finger. Even when the amp is quiet. It's NOT the tubes I have changed those out heavily in the past. -Voltages are all within reason and were posted in my old thread. -I'm not going into all the things that have been done but plate resistors, Elytics etc are all fairly new. Solder has all been reflowed and flowed again. many resistors have been changed out on a whim. So at this point I have two possibilities: -What can make V1 and V2 microphonic? I'm thinking the old Blue Mallory tone caps may have a bad one or two. ? I hate to start changing those out one at a time, as testing is inconclusive at best. I guess I could replace them all and see, then start filtering them back in.. ugh! -Someone in the past mentioned measuring for DC on the volume pots. I'm not sure how this is done? The pot case is grounded already, so what would I connect to measure this? -The other thing is some of the pots in this old amp have like zero resistance to turning, very loose. Could a pot be the culprit? I noticed the other day when it was "rustling" that when I turned the Bass pot back and forth fast, it stopped making noise. But these things are all often related, microphonic pre tubes, pots effected by that... etc. Any thoughts?