I cant buy the pre/power amp off of him because it is technically his mom's equipment. He has a ton of garage/barn space so he kept it for her and she "upgraded" to a bose system anyways. However, she randomly calls now and again and says "hey, do you still have my XYZ" and technically this wasnt his property to let him let me borrow. I went through and cleaned the crap out of it though and it works PERFECTLY.
It controls the audioengines' volume absolutely brilliantly. They are at just about exactly 50% right now. The subwoofer needed a tiny bit of a boost, it is past the 50% gain mark, but that is OK. I might need to tweak the crossover setting on the sub a bit because there are places where the HPM's woofers do a fine and dandy job of hitting notes, and I dont need the sub to interject at those frequencies. I might need to play with some damping material panels here and there to take care of a bit of sibilance/harshness issues, but it doesnt get too bad unless you accidentally walk RIGHT in front of the tweeters on the HPMs.
It turns out the audioengines dont need the CMOY thingy at all, and with the preamp at about 20-30% volume and A5's at just short of 50%, everything is just about perfectly volume matched, if just a tad bit bass heavy.
There is no stereo image to speak of, but that is to be expected considering my room is 10x10 and doesnt have any sort of room for such huge speakers anyways lol.
When I get done with these other purchases, I think a proper pioneer 5.1 receiver or something will be the best route to take. Depending on how long i can borrow this pre/amp I might be able to spend a bit more than 250 on the receiver and eliminate some wires here or there. I'm considering an el-cheapo sound card like the Xonar DG or something just for the sake of optical or coax output going to the gamma 2, which I can then feed into the receiver's AUX. The amp itself in the receiver is not something i'm terribly worried or finicky about, as my budget constraints and speakers dont really call for that kind of precision. If I had a set of B&W 800 diamonds though i'd be pretty concerned with the amp i'd be using lol.
Ive made a note about the cmoy thing though. I might let my GF keep the audioengiens at her dorm, and she'll DEFINITELY need something like that to control the volume if she uses them, assuming she uses proper optical or digital output to a DAC of some sort. I'll let her use them out of vanilla headphone output initially just so that when she gets a DAC like the Fiio D3 or D5 she will literaly be able to taste the difference.