Hifi: XTC PRE-1 preamp

I bought this second hand and found myself distinctly underwhelmed with the sound quality.
I decided to take a look inside, and reverse engineer it.
Imagine my disappointment when I discovered that the claims of "Uni-junction FET Preamplifier - Single ended class A" on the rear were untrue.
It transpired that the only FET device in the unit was the Op amp for the DC servo.

Update Sept. 2017: I found this XTC PRE1 / POW1 thread on the Pinkfish media forum, and the preamp illustrated here does indeed have the FET outputs, along with the heatsinks (missing in my preamp).
Interestingly, both preamps have the same "PRE1MB" and "ISSUE4" PCB.
Additionally, the silver PRE1 in my gallery (pictures were from Ebay) also show the same ISSUE4 board without the heatsinks.
This must surely mean there were running changes to the design at the factory at some stage - my guess is these were later releases?
If anyone has any information on this, please email me and let me know!
I have copied the pictures from Pinkfish media and added them to the gallery below for reference.