Home › Forums › Help/Technical Questions › Cure Noisy Vintage Big Muff?

Viewing 14 posts - 1 through 14 (of 14 total)
  • Author
    Posts
  • May 12, 2009 at 9:54 pm #78223
    devnulljp
    Participant

    What’s the best plan of attack to cure a noisy old Big Muff? Al muffs seem to have some level of noise associated, but some are better or worse than others. I have a v2. lamb’s head 3003 and a red/black v3 3003 that are pretty quiet, a 70s IC little big muff that’s OK, but a muff fuzz and a 80s v6 3034/tone switch that are both pretty noisy.
    What would you start replacing to cure the noise first? What are the most likely candidates for causing the noise?

    Wiring? Capacitors? Jacks? Pots? Switch? Transistors? Something else?

    The 3034 switch is a bit finicky, so I’m thinking about replacing that first, and the tone pot is scratchy. it sounds good, except for the excessive background noise. Will jacks make that much difference?
    Can I just bang in some orange drop caps of the same values and be done with it?

    Thanks

    dsc_0050-1.jpg

    May 13, 2009 at 5:54 pm #96668
    devnulljp
    Participant

    Anyone know what values I want on the transistors in there? They’re S2N5088, which I can get at Small Bear right?
    Or should I go for low noise 2N5089 (I can get a bunch of 30 over on diystompboxes)
    Also, I’m guessing the electrolytics will probably like to be replaced — good idea?
    Effects connection has 2N5088s in batches of 10 — what %age would be usable?
    2n50881.jpg

    May 14, 2009 at 1:53 pm #96681
    The EH Man
    Moderator

    Just any old 2N5088 will be fine. Wouldn’t hurt to at least change the electrolytic caps out.

    May 14, 2009 at 4:21 pm #96690
    devnulljp
    Participant
    Quote:
    Just any old 2N5088 will be fine. Wouldn’t hurt to at least change the electrolytic caps out.

    Thank you Ron! I posted this over on TGP and, apart from the sane voice of Analog Mike, got a raft of OMG IT’s FULL OF MOJO DON’T TOUCH IT responses claiming you need NOS 2N5088 stuffed with faerie dust.
    So I can just buy a handful of any old 2N5088 from small bear and not worry about values or anything?
    Thanks

    May 14, 2009 at 4:48 pm #96692
    The EH Man
    Moderator
    Quote:
    So I can just buy a handful of any old 2N5088 from small bear and not worry about values or anything?
    Thanks

    I doubt you’ll go wrong on that route.

    May 14, 2009 at 6:58 pm #96693
    Fender&EHX4ever
    Moderator
    Quote:
    I posted this over on TGP and, apart from the sane voice of Analog Mike, got a raft of OMG IT’s FULL OF MOJO DON’T TOUCH IT responses claiming you need NOS 2N5088 stuffed with faerie dust.

    There was a whole lot of faerie dust goin’ around back in the 70s, so they might be onto something. Depending on the application of the faerie dust, it probably didn’t make the pedal sound better.

    May 15, 2009 at 12:46 am #96706
    Ned Flanders
    Moderator

    Remember to put the highest gain transistor in Q1 for best results as this stage sets the overall gain.

    May 23, 2009 at 4:33 pm #96952
    devnulljp
    Participant
    Quote:
    Remember to put the highest gain transistor in Q1 for best results as this stage sets the overall gain.

    What’s a good gain range — 70–100 hfe or so like a FF or higher?
    Are the 3034 muffs just quite noisy anyway? I saw blondegraemey’s vintage muff shootout on youtube and that’s kinda what he suggested; I’ve heard that elsewhere too, and it’s certainly true of mine. The switch is a bit flaky too, don’t suppose that’s contributing to the background noise?

    May 23, 2009 at 9:34 pm #96956
    Ned Flanders
    Moderator

    A good gain range is 600+ for all four Q’s. This is pretty standard in 5088’s so youl be keeping it much the same as it already is. 70-100 is ok for germanium fuzz faces (I like around 200+) but wont be much good in a big muff.

    May 23, 2009 at 9:43 pm #96957
    devnulljp
    Participant
    Quote:
    A good gain range is 600+ for all four Q’s. This is pretty standard in 5088’s so youl be keeping it much the same as it already is. 70-100 is ok for germanium fuzz faces (I like around 200+) but wont be much good in a big muff.

    600! Holy cow. That x4 of them explains all the gain :D
    Thanks for the info.

    June 3, 2009 at 4:36 am #97285
    devnulljp
    Participant

    Anyone ever tried using shielded wire in there to kill noise?
    Earth the shield at one end with the core as the conductor.
    Wouldn’t the shield then function to shield the core from interference == less noisy?
    Do it on the input at least…maybe I’ll try it and report back.

    June 21, 2009 at 10:16 am #98207
    devnulljp
    Participant

    So I tried putting shielded cable on input and output w/ shield to ground.Can’t say it made much difference.
    But, I also did the noise gate mod: banged in a 100k trimpot (wired as a variable resistor) parallel to the 100k to ground off the second gain stage (R14).
    There’s a fine balance between noise and too much gating; the gate does change the sound a bit but it’s kinda interesting. My pre-EHX Foxey Lady (a Fuzzrite) has a bit of a gated sound and this mod seems to lean toward that sound. Not as extreme as the gate in my old Uni-Fuzz though.
    (forgot to remove the trimpot adjuster before taking pics)

    Before:
    [IMG]”http://i440.photobucket.com/albums/qq123/devnulljp/Fuzz/Big Muffs/guts-pre_0010.jpg”[/IMG]
    After:
    [IMG]”http://i440.photobucket.com/albums/qq123/devnulljp/Fuzz/Big Muffs/bigmuff-3034_0001.jpg”[/IMG]
    [IMG]”http://i440.photobucket.com/albums/qq123/devnulljp/Fuzz/Big Muffs/bigmuff-3034_0003.jpg”[/IMG]

    June 21, 2009 at 10:03 pm #98211
    Ned Flanders
    Moderator

    Modding old big muffs=sacrilege! :)

    June 21, 2009 at 11:14 pm #98212
    devnulljp
    Participant
    Quote:
    Modding old big muffs=sacrilege! :)

    It was either that or retrofit it as a coffee grinder — it had the noise down pat. Don’t worry, I kept the wire (and all the faerie dust ;-) that came out of it, so I’ll put it back in if I ever decide to take it to the antique roadshow. :D

    antiquesroadshow2.jpg

  • Author
    Posts
Viewing 14 posts - 1 through 14 (of 14 total)
  • You must be logged in to reply to this topic.