Hi dcevens,
As for your concern about Don's preamp, if Don should meet with some tragic circumstance after you bought a preamp from him, Roy Muttram, and Bob Latino are loosely connected with him, so I am sure that they would help, but frankly his gear is well built, he doesn't have a lot of issues or else his reputation would be shot. Beyond that, there are plenty of people who have worked with tube gear for years and would be quite capable of repairing his gear if needs be. The ONLY real problems would be parts as he is using transformers and output capacitors from Europe so there would be a time lag as neither currently have US distribution yet.
As for your concern about Don's preamp, if Don should meet with some tragic circumstance after you bought a preamp from him, Roy Muttram, and Bob Latino are loosely connected with him, so I am sure that they would help, but frankly his gear is well built, he doesn't have a lot of issues or else his reputation would be shot. Beyond that, there are plenty of people who have worked with tube gear for years and would be quite capable of repairing his gear if needs be. The ONLY real problems would be parts as he is using transformers and output capacitors from Europe so there would be a time lag as neither currently have US distribution yet.