It recently occurred to me that it would be better to use a balanced configuration as a phono input than the standard unbalanced arrangement. The CMRR advantage would be particularly useful when interfacing a cartridge with a cutting lathe. Sometimes a long line between the cartridge and the preamp is unavoidable. The grounding can also be difficult to get right with the tonearm on the lathe chassis and the preamp down the wall.
The step up transformer for an MC cartridge takes care of this naturally but I'd like this advantage with an MM cartridge. I would run twisted pair to take full advantage of the topology. I think I would need a 50k:50k transformer to interface an MM cart to a more classic topology. That's not an easy to find or inexpensive proposition.
I thought the front end of the SSL 9k would be a good candidate. Here is a link to Keith's SSL 9K project. http://www.studio21.ch/diy/neeno/ssl9k/DIY_9k_Preamp.pdf
I don't know how to separate out the schematic on page 2 and post it, sorry.
I think only the components before the MAT02 would need to be changed. Any insights would be appreciated. Is the concept valid? Is this a good starting point?
The step up transformer for an MC cartridge takes care of this naturally but I'd like this advantage with an MM cartridge. I would run twisted pair to take full advantage of the topology. I think I would need a 50k:50k transformer to interface an MM cart to a more classic topology. That's not an easy to find or inexpensive proposition.
I thought the front end of the SSL 9k would be a good candidate. Here is a link to Keith's SSL 9K project. http://www.studio21.ch/diy/neeno/ssl9k/DIY_9k_Preamp.pdf
I don't know how to separate out the schematic on page 2 and post it, sorry.
I think only the components before the MAT02 would need to be changed. Any insights would be appreciated. Is the concept valid? Is this a good starting point?