MC transformers - what do they sound like?

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.

Dear David12: +++++ " . There are still compromises with the "ultimate", design, such as the boulder. Perhaps its more interesting to discuss which way you would design the best stage you could build, at any cost, would that be active or transformer based? I don;t know the answer. " +++++

I don't want to speak about Boulder, but you can read the review on Stereophile and if you read it in deep, both parts: subjective and objective/measurements ones, you can see that maybe it is not the " ultimate ". Certainlly by price it is, the phono/line preamp it is only: 46K.

Now, if you take a look around phonopreamps: what do you find?

FM Acoustics, Boulder, Rowland, Pass, Klyne, Levinson, Krell, Aesthethix, Supratek, Gryphon, etc, etc.: all these people choose active gain stages not SUTs Do you think that these " facts " are a good answer to your question?

Do you think that we take 12 years of work with our self active gain design just for fun?

Regards and enjoy the music.
Raul.

Dear Swampwalker: +++++ " One additional thought or question I would throw in the mix is this- are there certain upstream or downstream choices that affect the step up vs gain stage decision, all other factors being equal? " +++++

In my opinion, other than money/price, no know-how and poor interest in music quality reproduction I don't think exist any upstream/downstream about. The choice must be active gain stage.

Regards and enjoy the music.
Raul.

Rauliruegas...Transformers do have their proponents. In addition to the MC phono aplication, some prefer transformer-coupled amplifier stages over capacitors, and some prefer variable coupling transformers over pots for volume control.