Custom Big Muff Build.

[DrNomis_44]

That may be why I like the sound of it. I tend to like the gut-punch of mids forward ;-)

Cool looking PCB. Is there an advantage to phenolic vs the more common (at least now) green (fiberglass?) boards?

Not really, phenolic is what was easily, and cheaply, available back when the Ram's Head Big Muffs were being made, I've been getting more into having mids in my guitar sound, mids are where your loudness frequencies are, mids help your guitar tone cut-through a live band mix better.

Phenolic does tend to be more brittle than FR4 Fiberglass, especially when it ages.

Both phenolic and FR4 fiberglass, as insulating material, do the job equally, but I think FR4 Fiberglass has a higher dielectric strength, which is a measure of how much voltage an insulating material can withstand before suffering a puncture and leaking current, but, since the Big Muff only runs on +9V DC, the dielectric strength is a moot-point.