Tube Amp "Ringing"

I use NOS because most of the current production is not as good as it "used to be". Good tubes are the best place to start, and Vintage Tube Services is a good place to get good value tubes. Your amp calls for 12AT7's, 12AX7's and EL-34's. I don't advocate touching tubes at all while they're in use. I've used several tube dampers, finding Herbies Hal-O's to be about as good as it gets. You're not going to correct a microphonics problem with dampers. Once they becomes noticable ... time to replace tubes. Fortunately the small signals that you use are widely available. Don't try to be too cost conscious here. Try some used Telefunken smooth plates for 30.00 - 40.00 ea and see what you hear... Give Andy a call at VTS ... you can't go wrong. I buy 80% on mine there. Be careful on auction sites ...

Newbee,

Far as I can hear, the "ringing" is occuring at the amp and doesn't seem to be getting into the signal. I checked this out by turning the volume control up (slowly, of course) with nothing playing on my CDP, but with the CDP on, to see if any "ringing" was coming through my speakers. Didn't notice any. btw, where do you get the "simple rubber type rings that only cost a couple of bucks" as I'm somewhat of a believer in the KISS (Keeping It Simple) approach, along with keeping it inexpensive.

I agree with Tvad - tube dampers are no cure for sick tubes. Their primary purpose is to assist healthy tubes in presenting micro details for clearer images. They aren't what you need in this case.

A minor amount of microphonics can contribute to a soundstage appearing slightly larger than normal which on some recordings can be a positive thing. However, when they get to the stage that you are describing, they have gone past the positive effects and need to be replaced.

My amp the 502 uses the 6550 (currently using Svetland) or can use KT88. The 302 on the other hand is the Jolida that uses the EL34. Currently, in the 12AT7 positions I'm using NOS RCA Black Plates and in the 12AX7 positions I'm using Sovtex. Maybe this afternoon, I'll try to pin point which tube(s) is the "ringer". btw, any good suggestion on some good "low noise" tubes? Brashgordon, thanks for the Telefunken suggestion. Was going to get a pair, but the dealer I usually buy from was out of them at the time.

The best suggestion for low noise tubes are any brand sold by a highly reputable tube seller. You can be assured that any tube sold by Andy at VTS will be low noise, regardless of brand or model.

BTW, I would first look at your NOS Black plates as the possible source of the microphonic tube. As Newbee mentioned, just gently tap each tube with a pencil eraser. If you tap a microphonic tube, it will obvious.