Added an SUT...not sure I understood this

What mulveling said.  There is only one correct way to terminate the SUT, with a 47K ohm load (or higher in some rare cases for special reasons) across the secondaries and input to an MM phono stage.  With a SUT that has a 1:10 turns ratio (like yours), this will have the cartridge "see" a 470 ohm load, which is OK for 99% of LOMC cartridges.  It's really simple.  Don't overthink it.

The cartridge likes to see a load impedance that is at least 10 times its internal impedance or greater.  Your cartridge has an internal impedance of 12 ohms, so you are fine with a 470 ohm load.  (Greater than 10X ratio is acceptable.)  The load seen through a SUT is equal to the value of the phono load resistance (47K ohms) divided by the square of the turns ratio (10-squared = 100).  Hence the cartridge sees 470 ohms (47,000/100).  Your cartridge puts out 0.4mV at the standard stylus velocity.  So the MM phono stage will see 4mV, which is perfect for driving any typical MM phono stage.

Well, as I said, I removed the load resistor when I installed the SUT.  Thus, the SUT is driving my preamp's 47k ohm input impedance without modification.  The pre-amp was just serviced and spec'd out by ARC, so I know there's no chance its impedance or gain are other than as designed.

It sounds like everyone agrees with me on what adding the SUT should result in, both in terms of gain and tonality.  It's just that is not what is happening.  

Make sure your inputs and outputs to the SUT are not reversed! I've done this before. I've also accidentally stacked two SUTs, which actually goes backwards in gain (due to really bad loading). Double and triple check all connections. In your setup, that SUT should give you an extra 20dB of gain which is HUGE and absolutely noticeable. There's no way you should be pegging the volume unless something is seriously wrong. That line stage has 20dB of gain! That's an awful lot. You should be having the opposite problem - you should be able to hit 95dB relatively low on that volume control - like below 12 o'clock, for sure. 

@mulveling Thanks.  Clearly there is something wrong with this SUT.  There's no possibility of wiring it backwards since it has a built-in output cable and two sets of RCA jacks for inputs.

You are right about the gain on my line stage.  When playing from a digital source, my light fixtures start rattling before I reach the 10 o'clock position.

Dear @woofhaven1992  : For that cartridge you don't need to use any SUT. The SP 14 spec MC sensitivity is 0.25mv and your cartridge has an output 0.4mv, repeat you don't need any SUT and obviously not that low quality Denon that was a vintage entre level Denon line.

You need to read the SP 14 very carefully to make the rigth set up/gain for your SP 14 stand alone and check for every system link to avoid any hum/noise developed.

You are in the wrong path with a SUT, jus forgeret and focus on your whole system with that cartridge.

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.