MC transformers - what do they sound like?

>> I am looking forward to continued discussion on this, but mostly, I would love to hear a demonstration.

Open invitation to one and all! Hear it live! Bent Audio Mu's vs. one "no holds barred" FET gain stage.

Of course I defer to Thom's experience with better SUT's. If he'll ship me one we'll include them in the shootout and report. ;-)

I've also heard Frank Schroeder's unobtanium SUT's. They were certainly very good, but some other parts of the system were insufficiently transparent for me to note specific differences between them and the Bents.

>> ... are there certain upstream or downstream choices that affect the step up vs gain stage decision, all other factors being equal?

Great question. One thing that comes to mind is frequently balance. If a system or room happens to be tilted up or down at either end, it might be possible to compensate with SUT's by adjusting reflected impedance. I would never recommend such a "band-aid" approach, but it might work for someone who doesn't have the time, interest or resources to solve the problem directly.

I was not thinking so much of an attempt to compensate, rather a better interaction btwn either an SUT or a gain stage with a certain kind of cartridge or line stage, or amplifier. Just a question, I have no idea if that is true or if any generalizations can be made.

Hi Doug,

Hop onto Dave Slagle's forum at Intact and join the frey.

Likely you can get into the evaluation loop as these are being developed.

The forum category is near the top - "MC Step-ups". Note that in order to view any attached photos or graphs, you need to establish a logon. The text of the posts is there for all to see however.

This thread ought to whet your appetite:

http://www.intactaudio.com/forum/viewtopic.php?t=139

Once again ... the dislaimer: NO COMMERCIAL INTEREST, YMMV, etc. etc.

Cheers,
Thom @ Galibier

David12. I have looked at the K&K p[hono stage. Does it have nice tube warmth?
In M Fremer's colum last mnth he reviewed the art audio ref1, which is based on the K&K. he commented on overloading and distortion when using a .5mv lyra titan. This does not sound right. have you have any of these issues?

cheers Shane

Dear Downunder: +++++ " Besides providing gain, are good quality MC transformers transparent to the signal they are providing the gain to. " +++++

In absolute terms the answer is: NO!!!, it does not matters design or price.

Thom posted that this subject is very contentious one and I think that it is because the people no know-how and because they never had the opportunity to heard the right active gain phonopreamp.

Next are some issues about step-up transformers SUTs:

The SUT is an old patch for bad SS phonopreamps designs and for the inherent limitations on tube phonopreamps for handle low output MC cartridges. It is a " cheap/easy solution to a complex problem ".

Any SUT has many inherent disadvantages like: distortions generated at the core ( it does not matters if is: air core ), heavy phase discharge ( landslide ), high apt to take hum, the wide zone ( band ) can't go down to DC, severe roll-off at high and low frecuencies, the reactive impedance on the SUT is incompatible with the cartridge impedance: this cause that we never could have flat frecuency response when we are using SUT, this mismatch between the impedances promote that the signal that pass through any SUT will be equalized.

Any time with any of you we can make the tests and prove all those disadvantages and others like the additional cables that you have to use, additional connectors, the SUT is an additional ( filters ) link in the analog audio chain.

I want to let clear that there is no single advantage, in any way, using SUT's, any of them.

The SUT always be a : wrong PATCH.

In the past and for many years I was thinking that the SUTs were the best way to go till I learned about. I try almost any SUT out there, in my system or in one that I knew very well, and always corrupted the signal that pass through it, that's why in the last 10-12 years we design and active gain and perfect a phonopreamp with out SUTs: we try every single technology: bipolars, fets, mosfets, tubes, combinations, etc, etc ( btw, Doug: bipolars for MC and fets for MM cartridges ) and this self design is what I'm using for and its quality performance is far away ( very far ) from SUTs design and far from any SS or Tube today comercial design. In our design there are no trade-offs.

There are not many good phonopreamp out there ( and are expensives ) and this is because it is a great challenge to design a good phonopreamp that can achieve targets like: accuracy on RIAA eq. ( inverse ), deviation no more than 0.05db between 20 to 20Khz, enough gain with out noise and distortion free.

The challenge is too big for some phonopreamp designers and they choose the " easy path ": SUTs and you people have to suffer. That's not fair, for you and for the music reproduction.

Regard and enjoy the music.
Raul.