Vintage Electro-Harmonic Big Muff pedal Questions :)?

Hey! I just got this amazing vintage Electro-Harmonic Big Muff pedal at a thrift store very cheap. I had three questions about this neat pedal. (Photos attached)

The first question is, what year is this pedal? The front says Made in NYC USA. I do not see any serial or model numbers anywhere on the pedal itself. The potentiometer has the following letters/numbers on it: P0150 and 1378005

The second question is, do I need to replace any of the caps on this unit before turning it on for the first time? (Photos attached)

The third question is, where do I find replacement case screws for this pedal? This did pedal did not come with any screws.

Thanks a lot!

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2 Answers

  • Tony B
    Lv 7
    6 months ago

    I never thought I'd say this but (deep breath)... Tommymc is mistaken about the position of the pots. They were changed from being in a triangular position to a straight line in 1973. I had one in around 1976 and the three pots were in a straight line. This link might help you date it:

    I agree with Tommy about the caps. I wouldn't worry about changing any componants unless there's something actually wrong with the unit. I had a couple of Electro Harmonix effects in the 70s and, although the sound was great, I found them a little unreliable. The Big Muffin particular would occasionally just stop working. I take it home, disassemble it, check for obvious broken connections, find none, put it together again and find it worked perfectly.

    As Tommy says, the screws should be obtainable easily enough.

    • Tony B
      Lv 7
      6 months agoReport

      ...similar but had a different circuit and some different components and was supposed to sound better. I got rid of mine years ago and now have the green “Russian” version.

  • 6 months ago

    I think this website will help you a lot as far as dating the pedal.

    In browsing that page, I have to wonder if your pedal is as old as you think. As far as I could see, the arrangement of the 3 pots in a row (as opposed to a triangle) didn't happen until 2013. Also, the green circuit board looks modern. Most of the shots of old ones had brown boards.

    No matter the age, I wouldn't sweat about the capacitors. It's true that really old caps can fail, and that's a concern with vintage tube amps. With the low voltages being used in the Big Muff, I doubt that a failing cap would do any harm.

    As far as the screws, this is something you can get locally. Any decent hardware store has an aisle with drawers of specialty screws that you can buy by the "each." Bring the pedal with you so you can match up the threads. Ask the salesperson for help, it's challenges like this that make their job interesting.

    Good luck........

    Source(s): Playing guitar since 1964
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