OK, the AN uses them in a gain stage (interesting DAC/power supply that I recall researching @ some point).
So, assuming that they still test well I would definitely try them out in the preamp as they are fairly durable tubes.
This said, they (and other less on the warm side 6922 types) seem to be universally preferred in the AN DAC.
Canary Audio is a big mystery to me (and they are close by as I live in West Hollywood, CA).
Tried to research/Google their products in the past and always came up with close to zip as far as user comments go.
*****What 6922's are in the Canary now and what what sonic changes would you like to make?*****
Regardless, in the meantime I would pick up a pair of the inexpensive tubes I linked just to have a spare pair on hand that may actually sound quite good.
Old production Mullard 6922 types are a crapshoot unless you know exactly what version you want as they can differ quite a bit in sound.
On the other hand old production Amperex/Philips Euro are quite consistent, overall, as far as the sound of their 6922 production goes.
The detail/bass increases a bit when going up the ladder ECC88/E88CC/E188CC, but they all sound (again) similar.
Suggest you go to the Brent Jessee (sp?) site and look @ his inventory.
Last I looked he had good (to me) Amperex Holland and USA 6922 types in the $120-$220 range for a matched pair.
He also has cream of the crop versions, but in my experience the difference in sonics has been not been that noticeable (big of a deal) in the gear I've used.
DeKay