Siemens -Halske 6922

One of my favorite tubes I rotate these in my pre and phono, not a warm tube but very detailed top to bottom tends to move soundstage frontward. If your system leans to brightness may want to look other NOS options
Dennis

Neutral, accurate, uncolored tubes. Available as E88CC (6922 equivalent), E188CC (7308 equivalent - higher tolerances built to last 10,000 hours) and CCa (select high-tolerance 6922).

As has been said many times, the CCa is the best of the bunch. Expansive sound. Extended highs. Neutral across the frequency band. What else would you expect from a German product? Can be microphonic and/or noisy (go figure considering they are special "select" tubes).

The E88CC I have owned had slightly more emphasized bass than E188CC versions. Both have similar characteristics to the CCa, but once you hear a CCa it's tough to settle for the E88CC or E188CC if you can get past the price objection.

As Dennis said, the highs on all the Siemens tubes can be too much of a good thing. Part of the CCa's magic is that it gets right up to the edge of being bright, yet it resolves all the detail without going too far.

Those highs scare me a tad--the leaning toward brightness part. Another killer tube that is close to the Siemens Cca or Siemens Halske, but maybe a tad mellower on top. Or at the worst: neutral