The vmoda works fine on the CB-1. Every TRS I've tried seems to fit. It's not a particularly deep twist-lock.
The SHP9500 and CB-1 have no artifacts in treble, and the treble is detailed and well extended on both. The CB-1s are slightly warmer than the 9500s, although I personally find the 9500s a bit smoother, probably due partially to the soundstage and openness. I think the 4k range is higher on the 9500s, but the 10k+ upper treble is higher on the CB-1, for monitoring purposes I assume. I haven't tried them but I've heard the OB-1s are the warmest of the three.
None of them have Grado-level murdertreble, if that's what you're worried about. I'm treble sensitive myself and I'd know. One issue though is that even though the CB-1s are theoretically easy to power, they seem to have less uniform impedance across their frequency than the 9500s. They're picky headphones. I get a very different sound from different DACs I've tried, and honestly I find the sound a bit hollow on everything except a dedicated sound card or portable dac/amp or a DAP, in which case they sound great. A Cowon J3 makes them sing. A Samsung Galaxy makes them screech. So, be mindful of that. The 9500s have a similar pattern but less exaggerated.
A 4K emphasis of any sort os a no-go. A 10K+ is quite welcome for added air. I'll be powering them with the Mojo, which seems to yield well to most dynamics out there.
