Has anyone compared the EMT 139st phonostage to others ?

Hans of  ing. J.P. (Hans) van Vliet the Netherlands EMT specialist has built his "own" version of the Neumann WV2 phono for use in the EMT 927 and 930 with the proper power supply.

I am quite interested in one for my 927.  Anyone have a chance to listen to his version?

https://www.jpvanvliet.nl/neumann-wv2-based-phono-stage/

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.

Wow! What a wealth of information from Good Music. I will never own an EMT anything (not because I don’t like the company but just due to my own old age and set preferences), but the historical perspective GM conveyed is very interesting. I am left with one question and one opinion.

Question: Why and how do you use two SUTs per channel?

Opinion: A 12AX7 or any tube that closely resembles the 12AX7 in its parameters (very high mu, very high plate resistance, very low current capacity) is a bad choice for a cathode follower. Because such a CF will have a relatively high output impedance and a low current carrying capacity, and it is after all the job of a CF to convert a voltage to current in the process of lowering output Z. In other words, the 12AX7 is not a good driver tube. I do realize it has been done by companies other than EMT, or the various persons that make their built in phono stages, and it may sound great.

There is an Audiogon listing of the TPM-1000 transformers.

One one picture the explanation is given.

I can't upload pictures here a simple explanation:

- both 100% identical transformers are connected in series. (which means input impedance is doubled but this has no effect on soundquality at all)

- the core of both transformers are oriented 90 degrees to each other (hum elimination, once can even do it by ear and hear the difference)

So if they’re in series, then the net voltage gain is a multiple of the individual voltage gain of each SUT? For example, a 1:10 ratio will increase gain 10X at the secondary of the first SUT. Then that voltage would be again increased by 10X across the second SUT, for a total V gain of 100X? Why would that ever be needed? I must misunderstand the hookup.