Phono Preamp. With transformer or fully active

18:1 is a bit on the high side for a 103 but not terrible.  Problem with the higher step up and the 40Ω cart is any capacitance on the secondary claims the 20kHz+ info quickly.  The 103 is a 0.3mV cart and into a 1:18 loaded with 47K you get really close to the 5mV "Norm" for most mm inputs.  Now 1:70.... that is high... but also a perfect fit for a 0.05mv cart into the right cable / pre combo.

I don't see where the inductance comes into play here.  as long as there is sufficient inductance to cover the low end without going too low it falls out of the picture.  

An interesting anecdote about the 4722 and its ilk which can be wired 1:18 / 1:36 is you get just about the same output due to the 1:36 loading the cartridge below its internal impedance and the frequency / phase plots are quite similar with the 1:36 losing a little more than 1/2 a dB @ 20Hz & 20kHz.  I know of a few people who simply prefer the 1:36 hookup and given the similarity of the measured response of each it makes me wonder if any of this preference is due to the drastic load improving traceability ala Moncrief.  I know this seems in contradiction to what I said above but in this case the loading in both cases is right where the transformer was specified (ie 50K load) and the measured responses are similar so I see a window of possibility.  An unfair test would be to load the 1:18 setting with an additional 16K on the secondary and compare it to the 1:36 with a typical 47K.  The proper way to test it would be to simply parallel 55Ω with the primary of the 1:18.  The gain would be down around 4-5dB but the frequency response would minimally change.

http://www.intactaudio.com/images/SUT%20white%20paper/4722.png'

dave

@intactaudio
When I look at the specs of the 4722, it seems its bandwidth might be limited by the simple fact that it is meant to deal with a signal much stronger than that of a LOMC cartridge.  Or it might simply be that Altec didn't intend the application for much more than public address. But whatever the reason, by comparison on paper, any Jensen SUT transformer outperforms it in every way- take a look:
https://www.jensen-transformers.com/transformers/moving-coil/

 There's a bit of cult around the 4722, isn't there? One not from actual performance, right?

I specifically chose the 4722 to avoid the appearance of throwing another manufacturer under the bus so to speak.  The only place I have seen signal level have an effect on frequency response in SUT's was with units wound on cores with poor low level permeability in which case the bass disappears. 

I'm not sure of the origins of the cult of the 4722 but I do think you can do much better.  The jensens are nice but I do not consider the use of the rather heavy secondary load in addition to a Zobel as a sonically acceptable solution.  

dave

I do not consider the use of the rather heavy secondary load in addition to a Zobel as a sonically acceptable solution.  

FWIW they *are* designed for that. I totally agree regarding your comments about bad core design- my comments  presume a decent transformer to start with :) ...   I think the 4722 cult has to do with a recording engineer named Eddie Ciletti.

Boy;

Who would have thought SUT’s are so controversial in application. My 2 buddies , that are LP guys, both have fully active with lots of adjustability.
Their systems sound superb, with a Lyra & Purpleheart cartridges 
I think it’s best to start fully active, as it appears
Being a vinyl , newby, 
Then listen and see how it goes

jeff