Not many used 800s around if any, why I got an old 50w plexi as my first Marshall; I think by the time those around my age could afford new Marshall 800s rack gear was where the pros were going. I remember all the ADA adverts, and all the pros I liked using ADA MP-1; I had many magazines with the full page ADA bass rig on the back cover. I built my ADA guitar rig slowly, using a Peavey solid state power amp (400W maybe?), into my old Fender cabs before getting a pair of ADA 2x12 vertical splitstack cabs, eventually getting another pair of cabs and the ADA B200s power amp, and the rare MQ-1 equalizer, and an Alesis Quadraverb...it wasn't until the early '90s when I got the full ADA bass rig.
I eventually replaced the MP-1 and MQ-1 with an MP-2, which I still have. Here's my last consolidated ADA guitar rack before selling the MP-1, MQ-1 and B200s and the splitstacks:
View attachment 348977
edit: I briefly had an ART SGX-1000, and Nightbass