I use an EMT930st and I had the EMT R80 which is the early version of the 927.
I know the EMT V83 very well, I had a pair of those, it is fantastic. I also had the Neumann WV2a (stereo) which uses the legendary Neumann BV33 stereo inputtransformers.
Both are in general much better than the EMT 139st but again, there are the early EMT-139 mono versions as well. The monos are much better than the stereos, but to use two of them in stereo you need a dedicated powersupply because any 139 was built to be used within the EMT927 or early version EMT930st. The late (mostly Barco) EMT930s can only drive the 155st or 153st or the Suisse Eymann (but you can use the 155st in the early 930st)
The crictical part of the 155st is that the complete circuit was fed via the 6.3V filament PS part from the EMT 930 or 927 internal PS and that isn’t a perfect solution. Never the less the 155st isn‘t bad at all, due to excellent input- and output transformers it still will outperform many other RIAA preamps and it has other options which some need.
The Eymann is RIAA only and bettered the EMT 155st with RIAA this because it has its own Sanken-PS. One must remember though that the standard Eymand was MM 47kohms only, very few had MC inputtransformers!
A rare exception of the EMT 930st was sold in Switzerland as well with a Neumann SMB-2 tube phonopreamp. This preamp used a very clever balanced design with just 2 x 12AX7/ECC83 tubes. Not very typical for the old tube designs using EF804s pentodes but it’s sound quality was excellent. Maybe due to the small lower ratio Neumann BV33a inputtransformers which were very different to the high ratio 1:40/50 BV33 stereo-transformers used in the WV2a.
The SMB2 is quite well described here:
https://hifihaven.org/index.php?threads/neumann-smb2-valve-phono-stage-with-bv33-input-transformers-wv2-emt.9304/
but with a mistake, the SMB-2 does not use the 1:40 BV33’s but lower ratio!
and here:
http://www.audiotools.com/oldriaa.html
I never saw the mentioned SEV-2 though.
The super rare Neumann WV1 mono equalizers used BV27 or BV33 mono with lower ratio as well, I liked those much more, I am not so keen on high ratio but this is a matter of taste, the BV33 stereo is great in its way indeed and for many a high ratio is what is needed. For a high ration input MC tranny those BV33’s are for sure the very best and unsurpassed, no matter if mono or stereo. There is a difference between „modern“ BV33’s or vintage though, although the modern still are great but the vintage versions are far superior.
So a pair of EMT 139 monos with a dedicated PS will outperform the 139st quite easely and is a fantastic investment because they don’t lose value at all.
A lowcost bargain solution is the Eymann, but solid-state isn’t tube though.
As much as Neumann tube-microphones and Telefunken/TAB/Maihak microphone tube preamps define the real state of art, so do EMT 139 mono, EMT V83 (133) monos, Neumann WV1 monos and WV2a and SMB-2 stereo equalizers.
Of quite some importance of course is which MC cartridge is used.
The EMT 139’s all are designed for the EMT TSD15 and similar with a 2 x 24 ohms coil impedance, quite close to the Denon DL130. So those EMT inputtransformers are an perfect match for the TSD15!
But if you want to use the Ortofon SPU’s or other lower impendance Moving Coils you need the Neumans because their input transoformers are designed for such cartridges!
This doesn’t mean you can’t use the 139’s (or V83’s) with SPU’s but it isn’t the perfect match.
At the same time I have found that the TSD15 sounds very good with the BV33 or BV33a inputs.
To make things more complicated:
I always have liked the ZYX cartridges and used them on my modified Ortofon tonearm with standard headshell connection (as well as on a FR64s and other great tonearms).
I had tried the ZYX TPM100 inputtransformers which I think used amazing transformers possibly made by Tango or Tamura. But the I got the TMP1000’s which used 2 transformers per channel. This was an eye-opener, no, of course, this was an ear-opener!
As if a curtain which veiled everything was taken away in front of the speakers.
My immediate thought was to try this design with EMT and Neumann transformers and the result was fantastic. Since then I never ever used just one transformer per channel but two.
I know, this is more expensive but worthwhile. One has to connect the trannies the right way and understand about orientation of the core (90 degrees one core to the other), because then one has eliminated any possible hum to zero as well.
Cheers to the listing of „good music“