Driver Tubes 6922

     I've purchased at least 9 NOS matched pair of Siemens, E88CC iterations, over the past 20+ years, from Argentina, Germany (the most), Australia and off eBay. 

     None, in the last 10 years.  

     Mostly: early 60's, grey shields.   Actually: all but 1 pair each of early 70's, silver shield, CCa and E188CCs, which were sold because they seemed a bit too strident, in my system.

     My CDP takes 3 pair and I recently swapped out a sextet of the CCa's (3 different early sixties versions/getters) for 1 pair each of CCa, E88CC and E188CCs, just to see if there was any difference in presentation. 

      I was happy to find everything as excellent and quiet as with the all CCa set.

      I've stuck with Siemens as my go-to valves, because I found the 12AX7s, my previous CD drive and DACs* took, gave me exactly what I preferred, far as presentation (with nary a hiccup/failure), for quite a few years.

                                               Great stuff!

                  * (California Audio Labs Delta, Sigma and then Alpha)

All current manufacturers, at least the ones I have used should be utterly ashamed at their ineptness, apathy, ignorance, or whatever it is that makes them seemingly unable to make a tube properly. And I never knew what I was missing.

The 1.5 minutes of listening to Black Plate RCA’s and Mullards in my system (even when one of the tubes was dying at the time) showed me that modern manufactures are embarrassingly inadequate. There is absolutely no comparison.

                                        Couldn't agree more!

                                                     +1

     btw:  I've had 6SN7GT, Tung-Sol round plates, that got noisy in the same way you've mentioned, do to material flaking and getting in their grids.

     GENTLY tapping their pins (vertically) on a table cleared them up nicely.

     Never needed to try that with nine pin miniatures, but: who knows?

@tonydennison-

                   Should you not get an immediate response:

     If I'm not mistaken, Brent Jessee's on vacation/closed until Sept 5.   

         Rest assured: he'll treat you very fairly, whatever the issue.