if you are in the Los Angeles area, feel free to contact me. I have two Jensen transformer devices that I'm not using that you are welcome to try out before you purchase one.
In the interim, it is a very good way to go. I bought them because I was using single ended out from my previous crossover to balanced in to my amps. I then upgraded to a Krell KBX balanced crossover configured to work with my speakers and the need for the Jensen devices went away.
However, they work pretty good.
Also, before you decide to get another full function with phono (I presume) pre-amp, I would first retube that SP9 MK II with new tubes. I did that before and then auditioned a REF3 pre-amp side by side (A/B) with the SP 9 and I have to tell you, although the REF 3 was/is better, it wasn't a jaw dropping difference. and that retubed SP 9 MK II sounded really good.
enjoy