RM20 HCRP(?)

[Tuckerbomb]

Hey all, I just score one of these heads, and it came with a Grail module. I'm having trouble finding info on it. Mostly dead links. Does anyone know what the HCRP means?
Also, with the Grail module, it was sounding good, but I went ahead and swapped out the preamp tubes in it to some newer ones. And it really seemed to "wake it up" a bit. But, that's when I first noticed a red LED right between the treble & level pots. I don't think it was lit before.
I this just an indicator that it is on? Does it come on with bad tubes? Or did it indicate the old tubes by not lighting up earlier? Kind of confused.
Thanks

 

[Mattfig]

Heya! Welcome to the fun and congrats on your purchase! MTS will make you lust for tone like nothing else, be forewarned....

The light you see on the module is the indicator light showing that the Grail is selected. When you get more mods, (www.motorcitymods.com ) the selector light will always be on with the active module...

As for the initials, I don't know what they stand for....Sorry on that one....I bet someone here knows though...

 

[Spencer4hire]

HCRP stands for Head Cream Palamino tolex.

 

[Tuckerbomb]

Awesome, thank you both for the replies. I can't wait to try out a module that isn't stock!