Elektor had "The Preamp" in the 80's, published in three parts; december 1986,januari 1987, februari 1987.
At the time a very pricy pre-amplifier to build, because of the choice of parts.
The design has relay switched entrances and exits, a phono stage that is switcheable from MC to MD,with a RIAA correction within 0.2 dB.
The basic design used 3 Mat02 double transistors and 4 OP27, and a whole array of different types of caps.
In august 1987 came an additional headphone amp for the preamp, that used OP50's.
In 1988 there was another additive, a nonbalanced to balanced
converter, and vice versa, again with OP27, and the AMP01,OP227 AND LM325(i think).
Later came the possibility to swap the 27's for OPA627, i used Burr Brown versions for all the active components from the beginning. Regular was PMI, some even used 5534(not recommended).
The build cost then including the chassis was well over $ 1000 , if all recommended parts were used.
Dieter Burmester was the leader in Europe in opamp preamp technology at the time.
Elektor's "preamp" was among the top of the range of the preamplifiers using precision operational amplifiers.
It performed very well combined with discrete class A power amplifiers on dynamic loudspeakers and Quad ESL's, the phono stage was particularly good for those years.
I have listened to it connected to the best of the Thorens range, combined with topnotch CD players/DAC's(tube versions), and connected to a number of class A amplifiers (pushpull, hybrid, tube, Aleph 0s )
In my view after replacing the BB OP27 for BB OPA627 when it came on the market it became a preamp that still ranks among the best in opamp pre's around.
Should be, the OPA627 and OPA637 still go for $45 each here in Holland.
The last mod's i did on the pre before going back to discrete again was forcing the IC's in class A and swapping the integrated LM317/337 voltage regulators for a battery powersupply with 22 individual discrete regulated current lines.
I think till now it was the best achievable with opamps.
Better means leaving IC's, going discrete to fewer stages, going single ended.
(For that i have been sucking on NP's mind since day one.)
I'll have to dig for the schematics, may even have pcb layouts.
The basic phono/line stage has been built by quite a number of people.
jacco