Probably the first guitar amp simulator (before the Sansamps!) the JD-10 was named after Jerry Donahue of the Hellcasters. It was first built in the UK but later offered and distributed thru Morley. They are no longer made so I just had to build one for myself to see what all the fuss was about. I slightly modified this one for more low end to be used with a bass. The originals often had reliability issues and came in kind of a funky layout so this one is more pedalboard friendly in a standard 1590BB with top jacks and a true bypass stomp switch. This one doesn't have an XLR output so it's designed to run as a standard guitar effects pedal. I think that it's an awesome overdrive distortion for bass but can also be run clean if you want it to. The classic/rock toggle switches it from a lower gain OD to a high gain distortion. It also has a speaker simulator switch that cuts the top end and emulates the curve of 4X12 speaker cabinet. I am only going to offer this one for sale and it's already built and ready to ship.
Take a listen to the soundclip below to hear what it sounds like with a P bass.