Suggestions for phono preamp for LOMC's

@bobheinatz 

Here's a tip for buyers of phono sections that can work with LOMC cartridges.

If it has provisions for a loading resistor for the cartridge, its a pretty good bet the designer didn't think thru the implications of an inductive source (the cartridge) being in parallel with the capacitance of the tonearm cable.

FWIW, the understanding of this is taught in the first week of any electronics class.

The two (inductance and capacitance) together form an electrical resonance, usually at a fairly high frequency which could be 1-5 MHz. It can also be as much as 30dB higher output than the cartridge output itself. If the phono section wasn't designed to handle this energy with grace, it won't sound right; hence the 'cartridge loading' resistor. The RFI (since that is what this resonance is) can intermodulate with the input signal, causing harshness and brightness. The loading resistor detunes the resonance and so knocks out the RFI, but it also causes the cantilever to be stiffer, since the extra work to drive that low resistance load of the 'cartridge loading resistor' might be over 2 orders magnitude higher. 

I've found that if the phono section design took this phenomena into account, one side benefit is less ticks and pops which can be otherwise caused by the input of the phono section overloading from the RFI. Its nice to play entire LP sides without a tick or pop!

Ralph, Do you equate the resonance frequency generated by the inductance of the cartridge being in parallel with the capacitance at the inputs with RFI? I never thought of it that way, as I always thought of RFI as noise that comes from an external source either by radiation through air or by injection into the circuit wiring. The capacity of the phono circuit to deal with the high frequency resonance generated in the cartridge/phono system is identical to its capacity to deal with RFI, I guess.

Im using an Ayre preamp with my Ortofon Winfield.....works fine

Don't forget to consider my TRUMPET MC.

https://positive-feedback.com/reviews/hardware-reviews/hagerman-audio-labs-trumpet-mc-phono-stage/

I also use the PS Audio Stellar Phono Preamp. I don't have much experience with higher end phono preamps and I asked for advice on a thread in this forum. For me, it was the ease of use coupled with the good reviews that I saw. I was sick of having to open up the side or top of the unit and figure out which tiny lever to push for the LOMCs that I use. The PS phono preamp has a remote for the settings and you can make changes on the fly to figure out what works best. I've tried 2 different LOMC and I am very happy with the results.