Cavalli Audio Liquid Crimson Tube Rolling. Some notes on tube rolling with the Crimson:
Genalex Gold Lion 6922: 
Slightly on the bright side. The best of the new production 6922s I have heard. Compared to the old stock tubes, not quite as clear and resolving the mids. Definitely worth the price. I don't know why the old stuff always sounds better.
JAN Philips 6922: 
Nothing particularly special but definitely better than most new production 6922s. Mid-centric, but with a touch of warmth and maybe slightly laid back / inoffensive. Not the best at the extremes. The price is definitely right at $30. I'd easily take this in a pinch, especially if I didn't want to pay up the wazoo for the good 6922s.
Russian 6H23P-EB: 
Bassy and punchy. Dynamic with strong impact and attack. Slight u-curve sound. Sometimes muddy indistinct bass - maybe because of its bass presence. Other times a little bit sharp in the treble. A fun sounding tube.
Sovtek 6922: 
Bright or more precisely more upper-mids forward. Good clarity, good bass quality. These use to be new production 10-15 years ago and came as the stock / standard tubes on a lot of pre-amps. I actually like the sound of these and feel that they were vastly underrated. A lot of people felt that they sucked, but I think it's because these tubes do tend to sound brighter than most other 6922s. Obviously, this tube should be matched with appropriate headphone and/or musical tastes. I'm not sure if these are easy to find anymore. The EH replacement for these suck.
Telefunken EC88CC/6922: 
A touch warm and laid-back along the lines of the JAN Philips, but so much better sounding. Great extension / performance at the extremes. The most nuanced and resolving of the bunch here. Tends to fool you into thinking it might be too laid back, and then at the last minute surprises you with its technicalities. Just beautiful sounding.
