MM to MC back to MM

A direct comparison between MM and MC is difficult, because in common practice phono preamps have an extra pre-preamplifier stage or a step-up transformer to satisfy the extra gain required by MC cartridges. This introduces a sufficient loss of transparency as well as colorations, that will render the direct comparison useless.

For this test to work, both phono preamps should have identical number of stages, components, working conditions and signal response. This is of course not possible (due to the mentioned gain issue), but it can be approached within reasonable limits. With a good topology, it is possible to duplicate most of the circuitry without needing to have an extra stage (or transformer) for the MC cartridge, effectively rendering the differences between MM and MC phono stages irrelevant.

Having said this, I must also express that I still prefer MC cartridges. I have yet to hear an MM cartridge approaching the soundstage definition, the attack speed, and detail resolution of the best MCs (love the Dynavectors). Whether this has to do with the MMs having so much inductance, or its higher mass, I don't know for sure. This has to be investigated further.

Regards,

Jmaldonado...As I said in a prior comment, at least one such preamp exists (Tandberg 3008A). There are just 2 gain stages and only a couple of resistors differ between the MC and the MM circuits so as to adjust gain. (Of course the inputs have loading resistors and capacitors as appropriate for each cartridge type). It seems to me that if you can achieve a good MC preamp it is a trivial change to cut the gain for MM use.

On the other hand Rauliruegas has designed his unit with different circuits, and different transistor types, because he feels that each type of cartridge should have an optimal design.

Eldartford, how do you know this? Do you have the schematic or something?

Regards,

Jmaldonado...I bought the service manual, so I have the schematic.

Me too. Circuit City is selling them.