Calculation verification please

My wife is a brunette and I don't have the gut that guy has, but otherwise there is some relevance.

So yeah:

• For a typical fixed 47Kohm MM input, a 40x SUT gives your cart a 29 ohm load. You CAN’T raise that 29 by paralleling anything. If you try to add resistance in series, you will lose almost all of your actual signal before it hits the MM input (voltage divider). As mentioned earlier, you have to either modify the phono stage to get higher than 47K input (600K = 375 * 40 * 40, as mentioned ealier) or switch to an MM stage that has non-standard loading options above 47K.
• Rogue Ares has an MM option for 100K and 1 MEG ohm loading in MM mode. Phono stages with this kind of option are few and far between. 1 MEG would give you 625 ohms off a 40x SUT (1 million / 40 / 40). 100K is 62.5 ohms. Still, you target 375 eludes you. 
• A 1.4 ohm cart will be FINE into 29 ohms. Like lewm, I don’t see much value in going higher. I don’t hear much difference in small gradiations of load, at least until you’ve gone way too far (low ohms) for the coils at hand.
• Your 1.4 ohms screams "My Sonic Labs". If so, these carts also have high outputs - like 0.5mV. A 40x on this (20mV) is going to push you way towards the overload margins of most phono stages, which will likely have a very negative sonic impact - much more so than your loading concerns.

By normal convention "40/40" means 40 divided by 40, which is 1.  Just so not to confuse anyone, you probably meant 40-squared or 40 X 40, or 1600. 600,000 divided by 1600 (or 600,000/1600) equals 375 ohms, the load that Skos desires. I know you know that but some might have been confused by the way you wrote it. That Rogue with a built in option for a 1Megohm input impedance on its MM stage would work too, but 47K works as well.

Good point overlooked by me and everyone else: What LOMC requires a 1:40 SUT? If you guessed correctly that it is a Mysoniclabs with 0,5mV output, then your point is very well taken. 20mV of signal voltage at the standard stylus velocity will definitely overload nearly any MM phono stage, because the stylus velocity can go way higher than the standard 3.54 cm/sec or 5.0 cm/sec (the two standards for which cartridge output is calculated).  To justify a 1:40 SUT, you would expect that the cartridge output is not more than 0.15mV or preferably less.

By normal convention "40/40" means 40 divided by 40, which is 1.

Good point - division is not associative. Indeed I meant ((1 MEG / 40) / 40), same as applying the div operator strictly left-to-right without groupings. 

@sksos1 could you share which cartridge you're using? 1.4 ohm coils are fairly unsual, and "usually" a good match to 40x SUT - but not if it's an MSL, which are extra unusual cartridges.

Perhaps off topic, but does anyone know how MSL gets as much as 0.5 mV from only 1.4 ohm coils? No other cartridge maker gets close to this ratio. MSL's marketing blurb goes like "magic SH-μX core", but it's hard to believe a core material could net that much more generator efficient versus iron-based cores of other manufacturers. Could they possibly be using larger-than-usual gauge coil wire, which nets more mass but lower DC ohms for a given number of turns? If so, that feels like "cheating" 

Magnets and their proximity to the coils plus core material must be how they do it. The math for such calculations is complex, and I don’t know the equations. So off the top of my head, I can’t be amazed unless I knew the math and physics involved.