Hmmm... I use an Aleph P with my EMC-1, and certainly decided that my Red Dawn was a limiting factor, given the Pass pre's transparency. Further I modded the EMC-1 to "UP" level (RSVP if you want me to mod yours for 1/2 price), then found nirvana with SPM XLR. I'm not sure that I'm pretty sure that i would NOT have been able to resolve these levels of further purification with a lesser preamp.
So if you want to follow my example treat yourself to a cleaner top octave with the EMC-1 mod, then feed it through a cleaner top octave than the Blue Heaven, into a totally transparent pre like the Aleph P or similar. The latest "UP"grade to the EMC-1 lights up the top octave to a less laid-back character, but ya need a more resolving IC (in balanced mode!) and pre to appreciate it. Just my experience, but VERY noticeable.