MXR RR-104 Randy Rhoads Special Edition Distortion+

rmroza · Post by **rmroza** » 06 Mar 2025, 04:29

Attached is the actual schematic of an era correct pedal (1978-1980).

Also pics of the an actual RR-104 black-banded pedal. Vf=0.383 and 0.391. Era correct should be about 0.340-0.350ish. My green banded tested way the funk out at 0.618 and 0.831!!!

Some else suggested maybe there were component on the other side of the PCB....there are NOT. RR-104 and Randy's pedal is STOCK!!

rmroza · Post by **rmroza** » 06 Mar 2025, 04:33

Looks like I never 100% finished the PCB and final trace connections to the switch, but here it is. I'll finish up it when I get a moment

jalmonsalmon · Post by **jalmonsalmon** » 06 Mar 2025, 06:23

and old script or 2nd gen MXR DIstortion + & a plexi will do the trick thank you

Looking forward for this finished PCB,,,
Like a dumb ass, I sold my old OG pedal in fav of a RAT lol... (big box early 80s)

CheapPedalCollector · Post by **CheapPedalCollector** » 15 Apr 2025, 01:24

rmroza wrote: ↑06 Mar 2025, 04:18 I love when people talk shit out their ass like CheapPedalCollector and his comments "it IS Modded".
NO, it absolutely is NOT!
I have reverse-engineered it 100%. So, not opinionated, but backed up by emperical data!
It's an EXACT duplicate of an era-correct BLOCK diagram pedal that was installed in his pedalboard.
The only differences would be 1% metal film, resistors versus carbon film and newer IC and die.
The "correct" 1N270s era-correct and black banned RR-104 I measured are around .340-.350 = Vf
Yes, as someone else chimmed in.....an era-correct pedal as well as the one in Randy's pedalboard utilized a C500K Distortion pot and A50K Output pot!
Randy's settings again have been purported by opinon which all can wipe our asses with! Some people suggest this Output (volume) pot was cranked, which is 100% incorrect and a modern approach. In actuality in videos and photographs, most recently at the Rock and Roll Hall of Fame, this Distortion is CRANKED and Output around 9 o'clock and very low! As typical of the time period, you want dirt and not boost or to tighten things up, so the distortion is turned up to taste and volume turned up and balance between an active and bypassed status!

Don't be an asshole, jeez.