Bah, the KSC75's clips are just not good for the KSC35. I mean it sounds good, but the point where the clips connect to the KSC35 allow too much freedom and distance for the drivers and pulls it away from the ear, losing bass. Ironically, the KSC35 clips make the KSC75 sound better than the stock clips. Still, the KSC75 sounds better than the KSC35 when compairing them both with the KSC75 rubber clips, and the KSC35 sounds better than the KSC75 when using the KSC35 clips. All in all, best to keep the KSC35 clips on both for sound quality, and using the KSC75 with it's stock clips for comfort.
I"m constantly bending my KSC 75 clips back so they push tighter against my ear and give better bass. If you don't bend them they will naturally get bent farther and farther bent out from normal use.
I wish KOSS would would sell a pack of replacement clips the same way they sell packs of replacement pads > http://www.amazon.com/Koss-PORT-REPLACEMENT-CUSHIONS-Replacement/dp/B000O2KIMO