How to select cartridge output to match phono amp

I have a Musical Fidelity XLPS phono stage that has sensitivity specified as 350micrvolts and input impedance specified as 100 ohms.

From this I am not sure what level of output I need from an MC cartridge in order to work well with this pre-amp.

Would the Sumiko Blackbird with 2.5mV be sufficient? What about the recommended 47k Ohm loading for the blackbird? What will happen when connected to the XLPS with lower impedance?

Thanks for your help
John T. Riordan
I'm not familiar with the XLPS, but those specs are consistent with a phono stage intended for a medium-lowish output moving coil.

You have enough gain for cartridges down to about .5mv output. I'd look for something between .5 and 1.5mv.

If your input impedance is fixed at 100 ohms then you should consider cartridges designed for that. Plugging a cartridge that wants to see 47K into a 100 ohm load will overdamp the generator. The result will be a stifled, muffled, lifeless sound with a serious HF rolloff.

It's not hard to find excellent MC's with 0.5mv output. There are dozens to choose from in that range, and the majority actually prefer a 100 ohm load. I expect that's why MF designed the XLPS with those specs.

Note: has an online gain/sensitivity calculator. Very useful.
I looked their website and it says that it has both MM and MC inputs. The Sumiko Blackbird would be too much for the MC input but a good match for the MM.

The circuitry in the X-LPSV3 is similar to that used in expensive electronics. The RIAA is very accurate, the noise ratio is excellent and overload margins are good. Generally, its technical performance on both MM and MC is equal to some highly expensive stand-alone phono stages. Subjectives are personal, but we think that the X-LPSV3 will stand comparison with the best. It doesn't have a high price tag so many will not even look or listen to this little marvel. Forget the price and listen to the music.

Separate dedicated MM and MC inputs. Allows use of either cartridge type for the best possible results.
Wide overload margin. Extended headroom allows effortless handling of transients and dynamics.
Sophisticated PCB layout, with very close attention given to optimising circuit layout, the result of 30 years' experience with phono. Low noise, low distortion and accurate RIAA gives a dynamic crystalline sound.
Very low noise circuits. Maximum available dynamic range and low level detail resolution.

MM input
Sensitivity 3mV for 350mV output at 1kHz
Input impedance 47K Ohms
THD < 0.01% at 1kHz, 350mV out
Input overload margin 30dB
Signal / Noise ratio > 75dB unweighted
> 83dB 'A' weighted

MC input
Sensitivity 350┬ÁV for 350mV output at 1kHz
Input impedance 100 Ohms
THD < 0.01% at 1kHz, 350mV out
Input overload margin 30dB
Signal / Noise ratio > 65dB unweighted
> 74dB 'A' weighted
Good work Herman. If John's unit also has a 3mv/47K input then of course a Blackbird should be fine.

I hate these trick questions!
The Blackbird is a very nice cartridge.
I own an X-LP, the Blackbird should work just fine in the MM position. You may have to advance the volume knob on your preamp well above where you set it to play CDs, but noise and dynamics should not be a problem, twist away.
Thank you very much for your help. I found everyone's contribution valuable.

Yes Dougdeacon, mine does have an MM input as well, but I didn't even think of using it for an MC cartridge.

Thanks again,
John T. Riordan

The Blackbird is meant to be plugged into the MM section. Not to worry, as a practical matter there really is very little difference between 2.5 and 4.5 mv in my experience. The Sumiko line is very good at their price point regarding surface noise. Any additional gain in using your volume control is more than offset by the cartridge silence in the grooves.