Hello, I just acquired a working amplifier made by AB Systems. It is a ATD Series 221. Does anyone have or knows where to locate a manual and specs for this unit? Thank you in advance for any assistance.
Is it AB International? Your best bet might be the Wayback Machine to see if it crawled the old AB website. AB hasn't been around for maybe 15+ years, so finding documentation may be a bit of a needle in a haystack.
I had an AB Systems amp (AB Systems is the predecessor to AB International) many many years ago, and it was ancient even then. Cool that it still works! I think what you are talking about is minimum around 30 years old (probably closer to 40) so it is unlikely that there would be much on the internet for it.