Update on my phono preamp:

8991XJ said:
wouldn't it be the same as the first one?
I've read that it is a fine sounding unit and with the limited adjustability priced for people and not those that gotta spend more than their friends on their gear. Nice.

The MC-10 is a demanding amplification VLOMC at 70µV output, well below the standard LOMC of 2-4mV (200-400µV). I've had an MC-20 since new and run into gain issues but have a variable 50-70dB gain phono amp that works just fine with it and my other more usual LOMC cartridges.
Click to expand...
The Pyxi has a gain of 65.5dB in MC mode. Some users are using it with 70uV sensitivity cartridges., but the A weighted S/N ratio would be in the low 70dBs and would be just barely better than the best LP surfaces, which is not ideal. The max output from LPs would be about 600mv RMS, which is probably OK for most preamps.
 
8991XJ said:
wouldn't it be the same as the first one?
I've read that it is a fine sounding unit and with the limited adjustability priced for people and not those that gotta spend more than their friends on their gear. Nice.

The MC-10 is a demanding amplification VLOMC at 70µV output, well below the standard LOMC of 2-4mV (200-400µV). I've had an MC-20 since new and run into gain issues but have a variable 50-70dB gain phono amp that works just fine with it and my other more usual LOMC cartridges.
Click to expand...
Just thinking the $Nx outlay where N=the number of Pyxis I'd have to buy :)

I believe the MC10 Plus and follow-on cartridges in that series all had higher outputs. I actually have the original STM-72 matching transformer for my MC10...was thinking to try and put that between the MC10 and Pyxi to see if that helped with the gain - and without causing any distortion or other issues.
 
The STM-72 has 35dB of gain. That means that the impedance of the cartridge (c. 2 ohms resistive) plus the interconnect wiring is increased at the SUT output by 70dB or by a bit over 3000. That means the source resistance that the Pyxi sees will be > 6kohms. At that level the input bias current noise of the opamp will degrade the S/N ratio of the cartridge by a couple of dBs, but there should be no other consequence.
 
I had the MCA-76 head amp with my MC-20 decades ago. Let go of the MCA. I got an STM with the MC10Super that was on a tonearm I got. It did not sound good so it got sold. I have a couple Musical Fidelity AC-1 head amps and an SUT and Phono amp that allow me to handle LOMC with the phono amp having enough gain from my MC-20...but the discussions about the Pyxi are keeping me interested.
 
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