What follows is a post in wrote on AK 3 1/2 years ago. It may provide a bit of info towards answering your question.
"There's not much info out there on this particular model, so I figured I'd take what sporadic info I gleaned elsewhere and condense it here for anyone who's curious.
Throughout the decade of the 80's, it appears to me the AVA PAT-5 evolved in the following order:
Super Fet (SS)
Fet Three (SS)
Fet Three Plus (SS)
Transcendence Series One (SS)
Transcendence Series Two (SS) Mine is a 1986 incarnation
Transcendence Three Fet-Valve (Hybrid)
By 1990, within the all-SS models, the latest and best was the T2, and apparently very few were built, perhaps due to the upgrade costing over 1.5 times that of the next lower level upgrade (Fet Three Plus).
I've seen comments regarding PAT-4 and PAT-5 Super Fets, and they run the gamut, some not very complimentary. However, what few comments I found about the T2 were highly complimentary, so I figured I'd find out for myself.
Therefore, I recently found and bought an original owner PAT-5 Transcendence Two off the bay (still there in completed listings), and I'm very impressed with its performance. Its feature set is almost identical to the Mc C27 I recently owned, but can say pretty confidently I much prefer the presentation of the T2. Warm and smooth, yet detailed, whereas the Mc was warm to the point of a slight dulling of the presentation. Also, the T2's volume, and especially tone control steps are in smaller increments as well, for better control of the sound than the Mc.
The T2 preamp is part of my second system in the basement, and I enjoy it so much, I'm considering making a place for the system in my bedroom, where I can conduct more appropriate critical listening sessions. I'd really like to swap it out with the MX118 in my primary system and give it a good thrashing, but my wife is addicted to having a remote."
Well, that comparison never happened. No need, the MX118 proved to have a glare that kept me from listening as much as I did with the T2. Since we've moved, now the T2 and AVA Omega III 240 have been pulling duty driving a pair of Genesis IIs in the garage at the new house. That combo deserves a much better spot than in the garage, but I don't have a good spot for them in the house currently.
I wouldn't remotely think about selling them (everyone does have a price, though), due to the paltry going rate. I highly doubt I'd find anything with the sound quality and feature set (all the PAT-5 features are still active, including two phono inputs!, with disconnected low/high filters) these two provide, without spending considerably more.
Without trying to sound like I'm speaking for Frank, when he and I talked about me sending in my T2 for any kind of upgrade/improvements, the only thing they could do was to install modern lower-distortion current buffer ICs, making the T2 comparable to the current SS offering. I ultimately decided the slight improvement wouldn't have been worth the cost.