Electro Harmonix tube opinions

well, this might not be directly related as my experience is with the 12AX7EH whereas you want info on the 6922EH. However, FWIW, I like the 12AX7EH tubes in my CAT preamp. It lends a certain richness to the sound that the Ei12AX7 tubes do not. In my particular case the Sovtek 6922-12AX7EH combination works quite well & I've been happy with it for about 2 years. Overall, after having spoken to a number of people I know who use the 6922EH & reading the forums, I think that the EH tubes, in general, are very good no matter which one you pick.
I have *heard* that the 6550EH has a certain boom-boom quality in the bass. By 'boom-boom' bass quality I mean that the bass tends to show some over-hang & that it might be tending towards a 1-note bass character. This is 2nd-hand knowledge so weight it as much as you like. YMMV.

My experience with tube rolling is minimal. But, in my Kora Eclipse preamp, the EH6922's sound dull and lifeless compared to the Bugle Boy and RAM versions.

I also use a set of the 6922's with gold pins in my CJ Premier 17LS pre-amp. I love them! Highly recommended!

I have tried the EH (steel and gold pin), JJ, late 60's Siemens cca, some Chinese tube, Siemens 7308 in my DK VS-1 integrated amp. The original Chinese tube was similar to sound of Sovtek in some other equiptment Ive heard, only somewhat more "grainy", but with an even amplification of all frequencies. The 7308 was a bit dull compared to the others with uneven presentation of harmonics. The cca had a tendency to exagerate higher frequencies at expense of mid-range. The steel pin EH had a slightly exagerated volume to middle frequencies while the gold pin had a bit more exagerated volume to mid freq extending into the upper frequencies. The JJ's have a more even-handed amplification of all freq without unusual harmonic deficit, over all presentation similar to Telefunken. The DK does not have the resolution that some preamps have so your results may vary according to aplication. I've heard the above tubes in other stuff but not directly compared but very generally same results. Good luck and please let us know how it all turns out, Mike.

Thank you for the opinions.