Had a session the other night. Plugged the bass into my Avalon 737 with the Avalon set to "Instrument". Was getting signal thru the Avalon into my board, where I set the trim to appropriate level. Recording went fine over the two hour session. I only found out later that the bass was an "active" bass with it's own preamp circuitry. Don't know what brand. The next day I went to do a vocal through the Avalon and it wasn't working. It would pass only a very low-level signal through and no amount of knob twisting affected it. Put in a new set of tubes and all is well. So, is it coincidence that the tube blew or did the active bass cause it? I would have expected the active bass to perhaps distort the input but not blow a tube. What do you think?