step up for mc

Are their any differences in sound quality? Certainly.

Which is the better choice? It depends on your budget and sonic priorities.

I own a PV-11A and a pair of Bent Audio (S&B TX-103, copper) transformers. For the money they do remarkably well, though with SUT's it is critical to get impedance loading exactly right. This requires in-system experimentation with combinations of resistors. Don't expect optimum results from plug 'n' play.

I also own a world class active MC/MM/line preamp (Nick Doshi Alaap) which easily outclasses the c-j/Bent pair. The MC stage uses FET's and it has enough gain for the lowest of LOMC's. The MM and line stages are all tube, so that both raises and answers Viridian's question.

Why did Nick choose FET's for MC gain? Because in his circuit they provide cleaner, quieter low level gain than tubes without the ultrasonic ringing and bloat common to transformers. In the end, it's as much about implementation as it is about theory. Every gain device has strengths and weaknesses. It's the skill of the designer that makes it work, or not.

If you're on a practical budget a PV-10A with a good tranny is a real winner. The S&B's are one good choice, especially with the silver wire, and there are others. If budget's not a concern it's possible to beat trannies with (some) active gain stages, but it takes a major expenditure and the rest of the system needs to be able to take advantage.

There is an article in the September Sterophile by Art Dudley talking about transformer step-up devices for MC cartridges and how to select the optimal gain and loading for your particular cartridge. He discuss a relatively inexpensive unit from K&K Audio in NC (www.kandkaudio.com) that has selectable gain and can be bought either assembled or in kit form. I thought about trying one myself as I use an Aesthetix Rhea unit to provide all the gain for my MC cartridge. The only thing that has kept me from trying this is the requirement of buying another pair of expensive interconnect cables. This might be a good solution for your application.

I'd have to respectfully disagree with Aball. I'm also an E.E. I would agree that transformers are usually a better choice sonically than op-amps. Tubes seem to be about the least desirable way to do a high gain stage. As Doug said, it's really all in the implementation. Below a certain signal level the transformers will act as a filter because some of the minute changes in the original MC signal will be insufficient to induce them in the secondary windings. The result is a loss of low level detail. Now, whether that is a good or bad thing can be argued as a matter of personal taste. Much like the choice between detail and what some would call musical. IMO, if you're missing the details you're missing the music.

The key is to match the particular transformer load to a given cartridge. Don't expect to get just one pair of step-up transformers and expect to play around with tons of different carts. They might work well with a bunch of carts, but chances are slim. Rarely is synergy more important.

"Below a certain signal level the transformers will act as a filter because some of the minute changes in the original MC signal will be insufficient to induce them in the secondary windings. "

Amazing, over 25 years in this hobby and of all the reasons I've heard not to use transformers I have never heard that, nor does it make any sense to me. I see how transformers can be frequency dependent but not amplitude. Please explain.