Phono setting and MC/MM

If it’s a high output MC there is no problem! What cartridge is it?

Tell him to try, if it’s too quiet with LOMC then it’s MM phono stage.
If it’s MM phono stage he could add a SUT (or headamp) and it will be fine to LOMC cart.

I strongly doubt the receiver is switchable to MC.  He will probably need a separate "head amp" (phono pre-preamp).  I would guess old head amps are available used for $50-$100.

Probably an older Mac, they would do MM, MC or MI. 3.5mv or better would work, load the MC cart correctly and away you go.
No your receiver is a MM cart.

The MC cart you have unless it's like a 5mv or higher. High output MC 

Look up the model number on the cart and see what the specs are. Google works great OP without a name and model. They are all different..

Thanks for all the replies.

He is looking to pick up a pioneer sx780.

The cartridge is a Japanese name (I don't have the box in front of me).  Pic below.

https://ibb.co/3rfDXTK

Looks like we will hook it up and see if we need that head amp.

Pioneer specs

Specifications

Tuning range: FM, MW

Power output: 45 watts per channel into 8Ω (stereo)

Frequency response: 5Hz to 80kHz

Total harmonic distortion: 0.05%

Damping factor: 30

Input sensitivity: 2.5mV (MM), 150mV (line)

Signal to noise ratio: 76dB (MM), 95dB (line)

Output: 150mV (line)

Speaker load impedance: 4Ω (minimum)

Semiconductors: 5 x FWT, 11 x IC, 26 x transistors, 22 x diodes

Dimensions: 480 x 140 x 320mm

Weight: 11.2kg