Delos Loading

Phonostage A with 100Ω hasn't the same sonic result like Phonostage B
with 100Ω. It is a endless discussion, best you can do, try your setting
and what you like best, that's it. When you buy a new Phonocable, you can roll
the dice again.
The better your Phonostage is, the higher you can go (1kΩ-47kΩ),
less loading, less coloration (when you step down from 1k to 300, 200, 100 ...-
-> the higher frequencies are more and more dampened, sound gets slow and
dull but a lot of Preamps deliver a listenable result that way :-)
The majority of Phonostages are not listenable above 1kΩ, but this isn't a
technical fact, it is the limited knowledge of Designers to get a proper solution.
That's the reason for the recommendation: 100Ω - 47kΩ
(That means: it doesn't matter what you have, thank you for buying our
cartridge)

I have heard that HP from the Absolute Sound will only listen to cartridges at the 47k ohm setting. I guess with the equipment he uses, he can get away with that. But isnt that what you get if you use a step up transformer into a regular MM phono input?

If you are using a SUT into a 47k load you are pretty much screwed if you think that the higher the load the better. . let's say that your SUT has 10x turns ratio. Loading is given by

Resistive-load / square-of-turns-ratio

In this example: 47000 / 100 = 470

I agree with Syntax that loading dampens. But I don't agree that there is much difference between 470 and 47000. There is a miniscule voltage drop at 470. Now, at 10 ohms there is huge damping and a loss of about half the output (can't recall the calculations but I think this is in the ballpark) and there is no question that you can hear this and that it can make a harsh system sound tolerable. It can also tame a rising high end in the cartridge and / or ringing.

Why manufacturers state > 100 is because there isn't much difference. Below 100 you begin to notice the effects of damping.

I use a SUT (16x) into 47k (tube phono pre) for an effective impedance of 180 ohms. That is the "best" I can do with my SUT. I compared it to my SS at 47k and heard no degradation in the high end and transient attack.

Just my considered opinion...