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Why the clear blob? Can't adjust MXR el grande.

Discussion in 'Effects [BG]' started by scullum, Apr 12, 2009.

  1. scullum


    Jun 29, 2008
    Went to adjust the internal trim pot for the deep switch on my MXR el grande fuzz and found a clear blob over the pot which is stopping me from adjusting it.
    Sorta tried taking it off but it's stuck fairly well and was moving the pot too much, so I gave up cause I didn't wanna wreck it.

    Am I missing something? What's it there for?
    Any ideas on what I should do?

    Also it seems theyve set it at about +15dB and the factory setting is sposed to be +10dB. I've read other people have had different factory settings too, weird.

    Looks like this:


  2. bongomania

    bongomania Gold Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    The purpose of the blob is to keep people from tampering with the trim pot. Some trim pots, when tampered with, will make the pedal sound bad or not function properly. Whether that pot is "one of those", I don't know.
  3. scullum


    Jun 29, 2008
    Ok yeah but I'm pretty sure this trim pot is supposed to be adjustable. Plus I've seen other el grandes without this on the pot...
  4. grygrx

    grygrx Lookout! Here comes the Fuzz! Supporting Member

    Dec 24, 2003
    Columbia, MO
    Yes, it should be adjustable.. at least according to the manual.


    and a shot of mine (which also had issues)

  5. LowB-ing


    Aug 3, 2005
    Not only should it be adjustible, but adjusting it is key to making it sound its best. Factory setting is sort of muddy sounding, and yours have even more mud dialed in ;)

    Set it to CUT bass about halfway. (Halfway between center and zero) This brings out the mids nicely and still leaves you plenty of bass. You'll have to set the voume a bit higher to compensate, but the pedal has gobs of volume boost available so thats not really a problem.
  6. rcubed


    May 8, 2008
    Vista, CA
    Looks like a bit of hot glue on it. I'd think it would pop right off. Mark the current location with a pen before you play around with it so you know where the factory setting is.
  7. RCCollins

    RCCollins Supporting Member

    Mar 23, 2008
    San Diego, California
    did you buy it used? seems to me somebody might have put a dab of glue in there out of pure retardation
  8. warwick.hoy


    Aug 20, 2006
    Spokane, WA.
    Beta Tester: Source Audio.
    I would think that you could hold the pot in place with a pair of flat nose, vise grip, or channel lock pliers and pry that blob off of there. Maybe apply a small amount of heat with a hair dryer to make it a little more pliable. Someone shoot me if these are bad ideas.
  9. RCCollins

    RCCollins Supporting Member

    Mar 23, 2008
    San Diego, California
    While it IS adjustable, the primary reason the trimpot is in there is for factory calibration. they just decided to promote it as an "extra feature". It is possible that (the instruction manual graphic aside) that position was the proper factory setting for that particular pedal

    or not, just sayin
  10. I opened up my 105Q (also MXR obviously) and noticed the same thing on the two trimpots as well. Maybe it's an MXR thing?
  11. scullum


    Jun 29, 2008
    Hmm grygrx it looks like mine has the same broken trace too.

    Thanks I'll try that, assuming I can get the blob off :p
    Otherwise I was thinking of selling it and buying a Supercollider, assuming I could get one. But I'd really like to see what this can do cause it's got potential.

    Nah I bought it new which makes me think I shouldn't be tampering with it. At the factory they might have decided that for this particular pedal this is the only setting it should be at. Maybe it burst into flames at other settings hehe, who knows :p

    I think the blob goes down into the the hole as well, which could be a problem...?
    I'll try again tomorrow. Hair dryer could be the go.

    Thanks for the input guys.
  12. RCCollins

    RCCollins Supporting Member

    Mar 23, 2008
    San Diego, California
    Personally, I would go ahead and tweeze it out. Or just return it - I got one of these and I really didn't like it much at all

    JAUQO III-X Banned

    Jan 4, 2002
    Endorsing artist:see profile.
    I took a look inside mine today and there is no glue or anything covering the trim pot.
  14. scullum


    Jun 29, 2008
    I got it off :)
    I used plyers mainly.
    Still don't see why they'd put it on there.
    I set it at around -8dB and cranked the volume. Sounds much better. Will see if it works in a band situation tonight.

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