Hi Al2214
I have some new re-issue cryoed Ruby 12AX7 tubes and some NOS GE 5751 preamp tubes that were cryoed as well and I haven't heard any difference with their non-cryoed counterparts in my Jolida 502P amp. As for cryoed power tubes I never did any A/B testing between cryoed and non-cryoed. I do have some cryo treated Tung Sol KT-120s and they sounded great with the 502P and I haven't had issues with longevity.
I have some new re-issue cryoed Ruby 12AX7 tubes and some NOS GE 5751 preamp tubes that were cryoed as well and I haven't heard any difference with their non-cryoed counterparts in my Jolida 502P amp. As for cryoed power tubes I never did any A/B testing between cryoed and non-cryoed. I do have some cryo treated Tung Sol KT-120s and they sounded great with the 502P and I haven't had issues with longevity.