You've moved on, so hopefully not too late...
The Nak preamps weren't Pass designs I recall, only the Threshold Stasis-based power amps - and these with banks of output transistors (ten a side in the PA7 models I recall), took two hours to come on song from cold - I sold several and owned a PA5mk2 which used to just about come alive as I was going to bed on an evening music session! The ARC SP14 was in a different plane of existence with a huge deep and wide soundstage in comparison which the Croft 4PP had as well. My CA7 was well made though, but the line stage was musically bland sadly, despite the superb build *in the flesh* inside and out. Maybe they chucked too much into it, I don't know. The CA7 did easily beat a Naim 72/HiCap, but today that's not saying much as the Naim projected the sound forward and 2-D and didn't reproduce air and space as the 82/HiCap, 82/Supercap and 52/SuperCap did... Old memories here, apologies...
The CURRENT Crofts don't sound at all rosy and warm in terms of colouration. The old ones could and when I had the last 4PP preamp a very few years ago, Glenn talked me through 'neutralising' it, to bring it more up to date and it came on leaps and bounds. He wanted it back to do the phono stage and check the rest as well, but I never did it and it's long gone now sadly. I hear the Micro 25 regularly and it's superb. My vibe is that Glenn has got an honest 'tone' from the stock valves he uses, but if you wanted to sex it up, you could look out some vintage or mil-spec valves. As supplied, it's honest to the source as checked with an op-amp based preamp that has no 'sound' at all that I can hear.
The Croft phono stage is good too but MM only, but I digress.
I'm only mentioning Croft because the M25 can be upgraded later. The Micro basic available a few years ago can't be updated by Glenn and sounded a bit scrappy in comparison I remember. Glenn's a good guy and loves his music. The whole 'Keep It Simple Stupid' ideal is very much alive in his world - thank Gawd!
Last edited by DSJR; 19-06-2018 at 08:34.
Tear down these walls; Cut the ties that held me
Crying out at the top of my voice; Tell me now if you can hear me