funny connection of spade cables

Hi all. I have kind of dumb question here. I recently bought a Quad 909 amp, and got excited and wanted me new cables, so ordered from Audio Advisor a pair of their bi-wire Audioquest Slate, which were in sale. I ordered spades on both ends, before bothering to check if the amp takes that. Of course, it does not. Intended to cut the spades off and use bare wire, but then I saw they are so nicely terminated I decided to postpone that until I figure out what to do. So here is what I did: The terminals on the 909 have classic banana connectors, but also a pair of side slots in which bare wire can be inserted. I discovered that one of the arms of the wide spade fits perfectly in there, leaving the other arm outside, and once tightened fits snugly. Sonically it sounds good, there is definitely an improvement over the no-name cables I had before, but of course I have no internal reference to compare this to.
My question is, what and how much am I losing in terms of sound quality? Is there any danger in using them like this? How much improvement will I have it I do cut them off and use them bare? Anything else I could do, like wrap the free spade arm in something? Would using one of those spade-to-banana adaptors, which AA sells quite cheap, be a better option?
'nough questions for ya? :)
Thank you very much!