Voltage mode vs current mode phono stages

Boothroyd,

I found this in the Sussuro cartridge owners manual:

"Please also note that some designs of “current amplifier” preamp circuits will not allow loading in the range required, causing the Sussurro MK II ES to sound very dull – caused by improper loading, resulting in loss of high frequencies."

What I could not find was a spec for the inductance of the Sussuro, but if memory serves it is about 50 mH.  This would give an impedance of 314 ohms at 1000Hz.  Let's say it's only 10mH; then divide 314 by 5.  Still high for a typical current driven phono.  Add the impedance due to inductance to the coil resistance of only 10 ohms.  I emphasize again that I love MI cartridges as a rule.  This is more about the usefulness of most current driven phonos stages.

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 already have the program so, yes I plan on trying it. But, I am ordering the RIAA board as back up. I should be able to do it with the equipment I have now as long as I do not get into a jitter war. Channel D recommends a combination ADC/DAC using the same clock. Their favorite is the Lynx HiLo. Nice unit but I would rather not have to buy one. I'm pretty sure digital correction will sound fine. The question is how much more of a pita is it going to be playing records that way vs the old fashioned way. You know I will be happy to forward my opinion.

Peter Ledermann related to me directly that his MI cartridges will not work well with a current mode phono stage. The high frequencies will be rolled off. He did not give me the reason why but I am sure it has something to do with inductance and impedance.

I don’t understand. If you order the Channel D with digital RIAA, then you have to supply your own outboard AD/DA converter? Or does the Seta output a digital signal that the user has to convert back to analog, or what?

Yes, the Grail is a very under-exposed amp.  I have had the SE for two years having auditioned it at home for three months against two other similarly priced units (COVID prevented the dealer taking it back).

There are three Grails.  SE is the middle one, perhaps a bit more towards the flagship than the base.  It can run single ended or balanced.  I run balanced from cartridge to power amp.

Grail has a good claim to be in the best sounding group of phono amps.  It manages to combine a near clinical accuracy with a musical presentation, which is rare in phono amps; one usually has to favour one or the other - as others have stated, warm or lean.

I won't be replacing it.