Best 12AX7 for CAL Alpha

anybody use one of these, if so what tubes work best, thanks for any info
There are a handful of us with Alpha's that enjoy the sound of the low cost Yugo tubes and they allow you to afford other recommended tubes at the same time.Happy listening.
Best bet is to go shopping at Lots of options; your end decision will depend on the desired sound.
I was considering selling my Alpha until I tried a pair of Mullard CV4004s. These are the tubes that Upscale Audio recommended to me. I was surprised how this little DAC came alive after they had time to break in. A substantial upgrade over the stock tubes...
I agree the Mullard CV4004's are great! I also liked the Telefunken(ribbed plate) 12ax7's.
Has anyone tried a set of 5751's in a CAL Alpha? Results?
I loved JJ Tesla 12AX7s on my Alpha. The stock Chinese tubes were a little faster, the Teslas richer. I also tried GE 5751s and was not impressed -- to slow, too golden sounding. I found myself longing for the fast Chinese tubes.
I have tried the GE Jan 5751, CV4004 and Sovtek. To me 5751 is the best sounding so far. As detailed as CV4004 but more warmth and a little laidback.
While the 5751 is not always a good substitute for the 12AX7, it does very well in CAL DACs. An inexpensive and well-regarded 5751 is the Raytheon. These can be had for around $20 each at places like Tube World and I prefer them over GE JAN grey plates. 5751s have less gain than the AX7s.