Hi there, I wanted to ask your help with identifying what I found at my old man's place. It seems like it is a legit Marshall Combo from the 80s, but what puzzles me is the "Bright" switch that is there. The closest I came to identifying this is that I think it is a modified Marshall JCM 800 4210 50W with Dual Channel and Master Volume as it looks very similar to these (i cannot post links yet, but there are some on reverb.com or amparchives.com): But having said that, I am completely unable to find a model with the bright switch (that is above input). Can anybody help me? Or has this combo been tinkered with by somebody else and that is the origin of the bright switch? Thanks a lot!