Thanks, I was just curious after noticing that it had much less gain than the others. Knowing Marshall, I guess that may or may not have been intentional. I've seen a few people on other forums say they removed their's so it sounds like at least some of them have it installed from the factory.Our reference amp has no bright cap. Looks like it was that way from the factory. There are no signs it was removed. The location in the circuit board is empty and the solder joints do not appear to have been disturbed.
Nothing preventing you from turning it on though. Lot easier than soldering one in.
Our reference amp is a later effects loop version and there definitely never was a bright cap in it. I doubt the chassis was ever removed from the shell, still has the original tubes.The versions without the effects loop, and some of the earlier ones with it, had the cap on the pot, not the PCB (although there was a spot, C5, for it). 4700pF, definitely supposed to be there (and makes the volume work like a switch).
I have two JCM-800's and removed the bright cap and an interstage resistor/capacitor peaking network on both which brings the high end into a more manageable territory with plenty of presence/fizz/high end on tap if you need it.My custom JCM800 has no bright cap. And maybe one interstage coupling cap increased in value. No fizz but probably doesn’t cut live. Fractal rocks for allowing us to tweak the bright cap to taste.