JUST saw this and am shocked. Bob was a truly good guy. He will be missed by MANY.
I will relate a story that I hope will be of interest to more than just me. Several years ago, when I had gotten back into two-channel audio, I was visiting a shop in Berkeley, California. Two guys were in the shop milling about and talking to the guys working there. One said he was there to pick up a copy of Stereophile because he did not want it seen delivered to his house anymore. :-)
The two of them struck up a conversation with me and were very pleasant and offered me a couple of suggestions regarding some questions I had. At the time I thought to myself that these guys knew more than anyone in this shop, or most any shop I'd been in, for that matter. Very unusually, I did not introduce myself, nor did either of the two. When they walked out of the shop, the owner said, Great guys, huh? - or something to that effect. I said, yeah, do they live around here? He said, you didn't know that those guys were Bob Crump and John Curl?
Later, I had several conversations with Bob and he joined a "cartel" of four of us that pooled in money on a Wally Azimuth Tool when he could have just bought one himself.
RIP, Bob!