I had one too, a White Anniversary one at that. Bought it from a kid and his dad in a music strore parking lot when the clerk inside wouldn't even take it in for a trade. I paid 75 bucks. Had a master volume channel and a non master volume channel. SIX 6550s. Loud as all get out. I sold it later to a collector. Not a great sounding amp.
-there was a 250watt. 1978-ish-(only made for 1 or 2 years)-JCM 800-half bass amp-half stock-(guitar)-JCM 800-(2 separate, independent pre-amp section's, one for bass & one for guitar)-
-always thought this would be a killer amp to get modded)-