Voltage mode vs current mode phono stages

@lewm 

My question was more about the effect of MI inductance on cartridge output impedance as frequency increases and how that affects the efficiency of current drive.

Seems like a question for PL. I would pose a similar inquiry for J Carr to the evolution of the Lambda Series of Atlas & Etna as their current delivery seems to be much improved over previous versions. I suspect lower inductance generators.

Maybe some CH Precision owners could join in?

Their reference phono stage allows for both voltage or current gain situations by featuring an array inputs which are easily user optimized.

From the info I’ve gathered, the 10 ohm or lower LOMC Current Injection (transimpedance) theme as mentioned by @lewm seems to be their preferred method of playback.

LOMI pickups are now joining the current party! (pun intended)
 

SoundSmith

@lewm 

Have you tried to drive a current mode phono stage with an SS LOMI?

While I have not, Peter explained to me that he is quite impressed with the results as long as suitable phono cables are utilized - something which I’ve often tried to emphasize. 

@lewm

"Suitable" = very low capacitance, I assume. 

Please excuse my ignorance and technical understanding, but I have a strong opinion that the + & - cartridge signal paths should be as similar as possible. Such a belief shuns any use of coaxial cable - yes, inductance not good.

On transimpedance phono inputs featuring RCA style inputs, such an assumption isn’t so intuitive. Knowledge of SME’s use of twisted pair phono cable construction sheds light perfectly on this scenario as each + & - path of their RCA outputs feature identical runs all the way back to the cartridge pins exhibiting perfectly balanced cartridge signals without XLR outputs. Continuing on that theme, SME only accesses the optional signal shield via a “drain” wire which exits the rear of the output RCA connector for optional noise control if needed - just tie it with chassis ground.

As far as keeping capacitance low, as long as each + & - cartridge signal path is again equal, I cannot see where that would hurt - Mogami W2549 works exceptionally well and is a well known low capacitance conductor.

lewm,

I would reach out to PL for clarification. FWIW, he was using a Loco with one of his LOMI pickups when he indicated the results were very encouraging as long as proper cables were used.

@lewm 

I am curious about what happens when you mate a Sussuro, for example, with a current driven phono stage.

This post from a recent Little Loco thread may shed some light:

I ended up with a Soundsmith Sussurro cartridge, but the Low Z (Low impedance) version. I would suggest if you were to buy one make sure Peter Lederman knows it's for a transimpedance stage.

The long version is that I contacted Peter and he contacted Ron Sutherland and compared notes. Peter built a low impedance version of the Sussurro and sent to me. I didn't like it, thought it was rolled off up top a bit. Peter offered to refund my money but I told him I would prefer he try to resolve and asked him if he would be willing to put in the time to do that. He agreed and I ended up sending the cartridge and the Little Loco to him to work with. The results are as you would expect if one of the most knowledgeable and talented guys in the cartridge/phono industry had your gear on his bench...an excellent match, I'm loving what I am hearing. 

My comparison is the Audiotechnica ART-9 which sounds pretty darn good but not nearly as good as the Low Z Sussurro, and my digital: Innuos Zen MKIII and Bricasti M1 SE MDX (who names these things?!) DAC. 

I actually picked the cartridge and Little Loco up at his shop because I was in the area visiting family. Peter took me on a tour, we listened to music, talked about dogs...he's a great guy, I'm really thankful for the entire experience (and for sure I'm glad he was willing to take the time to make the cartridge sound so good).