[bikerhifinut]

version 3 now up and running and so far very good I think.

I took on board the advice in regard of an accurate RIAA EQ, I tried to work it out for myself but my head was swimming with the equations, and so I cribbed the RJM EQ as I already had the components matched up from build2 which didn't work well at all, probably due to my construction rather than any other faults.
I have a circuit to hand to build an inverse RIAA network and that will be the next job to hook the board up to my sig gen which can output down to 2.5mV so I can scope it and get an accurate (ish) idea of how it all works.

Now, I know it was disapproved that I should use the Hitachi HA12017 chip for various reasons but I'd already rashly clicked on "buy" and they arrived within 14 days and with 10 of em here I figured I had to see what I got.
Well at 50dB gain ( I shall likely drop that to 40dB if I decide to build a "neat" version as a keeper) it has a very quiet background, hiss is only audible once the volume is cranked round to antisocial/overload levels.
That is a nice, I guess, confirmation that my mania for pursuing an ultra low noise device was misguided! I did use metal films throughout to keep noise down and the EQ capacitors are all Polystyrene that I nearly threw out years ago...…….
Its fairly close to the data sheet example circuit, no real detours apart from choice of EQ and feedback ratio.
I would rebuild this on a larger board, or perhaps 2 separate boards next time as the extra parts made it quite congested although a competent PCB designer/constructor (ie not me!) would probably get it on that small board with relative ease. So apologies for the awful point to point wiring underneath, but it works.
It's playing now and the noises coming out of the Quad ESLs are very pleasing ones, no funny rustles or squeals and whistles. I used the standard 100pF loading across 47k for the ortofon 2M and I think its about right for my tastes.

Can I thank everyone for their help and forbearance. It's been fun and if I get my head round the inverse RIAA thing I might use it a testbed for different EQ configurations based around feedback.

Andy