SUT experience

Oh yea I mentioned earlier im using a project tube box MM phono pre at 60db gain into the line level input of the Mac.  I want a better standalone phono preamp after I know with certainty what features I want. The pro-next was an inexpensive way to test the waters. 

adrianleewelch OP

"The preamp is a C47, not a 27. It’s a modern unit"

What Saturday Night Live character said "nevermind"?

Perhaps someone following along will benefit from my error and yap.

@elliott your reply was extremely informative though. I appreciate you sir !! I always stayed away from SUTs because I didn’t understand the math and the best way to match them with my cart.  I have a sumiko blackbird, Ortofon SPU century, synergy, #1s, #1e, and an AT OC9XML   I bought the Entre plus a FR3 so I could experiment with different settings to see what I like best. I haven’t even hooked up the Fidelity Research yet. It seems like the Entre will cover the range of carts I have from .18 up to .6.  The internal impedances vary quite a bit also but the 3 and 10 ohm settings both work well unless I use the 3 ohm setting on the .5mv cart.  It was extremely overdriven and distorted.  This is a fun experiment for sure.  

Adrian, do I understand correctly that your using an Ortofon SPU cartridge into a 10 ohm SUT into the Project phono MM inputs with phono gain set at 60 db, then into the Mac linestage? The SPU makes 0.2mV. Assuming your SUT steps up signal voltage by 1:10, that means 2mV into the Project. 60 db gain equates to a voltage gain of 1000. So the Project drives the Mac linestage with a nominal signal voltage of 2V, which is already enough to drive any typical amplifier to full output. But most active linestages add additional gain, like 10-20db. Is your volume control nearly fully to the left? In any case, try the 50 db gain setting on the Project.