I haven’t heard it but just saw it on his webside. It looks very well made, I am sure it will be a very interesting design.
Yet there are differences to the WV2a design:
The WV2a uses the EF804s in the inputstage, here it is similar.
The 2nd stage in the orig. WV2a uses another EF804s, before there is the passive RIAA network and in the original the switch for other different curves (not really necessary though if RIAA is all that is needed). Again similar.
The inbuilt PS of the EMT 927 and 930 won’t deliver enough to drive the E80CC
which is used in the WV2a, a very strong and steep triode, so he uses 12AX7’s instead, possibly just as cathode-follower to gain a lower impedance.
I have done the same but used ECC808’s instead of the 12AX7.
The ECC808 is quite similar to the 12AX7 but I prefer NOS Telefunkens here.
I had built a few complete preamps with this Neumann design (including line-stage with a Western Electric triode (417A) and dedicated outputtransformers.
So I know something about the design and can say that it sounds wonderful, I am sure Mr. van Vliets design will sound fantastic.