Amp doesn't make noise until I turn volume and gain (and guitar volume) past 5.

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by NoahL, Feb 15, 2009.

  1. NoahL

    NoahL Member

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    I have one of those little solid-state Marshall 5005 Lead 12s from the '80s. These are supposed to be nice little practice amps that can dial in a nice Marshall tone -- nice enough that Billy Gibbons supposedly has used them to record. I've always wondered if mine is normal: If I have both the volume and gain on 5 on the clean channel, I don't get any sound at all from the guitar until I turn the guitar past 5, as well. So basically, at least one of the three knobs (two on amp, one on guitar) that relate to tone have to be past 5 in order to get any sound. It's at least as stingy on the dirty channel. (This is not a switchable amp; clean and dirty are separate inputs.) Now, once I start to get sound, it comes on pretty fast, so dimed on the amp with volume is pretty loud and dimed on gain is, of course, volcanic. But is it weird for an amp not to surrender any sound at all until both gain and volume are at least at five? If it's not normal, is it also hampering tone in some way? P.S.: This is the same with every guitar I own.
     
  2. NoahL

    NoahL Member

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    P.S: I mean at least one of the three knobs that relate to VOLUME, not tone. (Gain and volume on amp; volume on guitar.)
     
  3. Rosewood

    Rosewood Member

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    Sounds like you've eliminated the guitar as the problem so you'll have to have the amp checked by a tech. When you say no sound, are you saying low volume or 0 sound? If it's low volume is it distorted? If this amp has an effects loop you might try jumping the loop with a short cord. Move the cord in the input jack to see if the volume will jump up or down, could be a bad connection.
     
  4. Rosewood

    Rosewood Member

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    I just looked at a layout of a Marshall 12 and it has a headphone jack, that could cause the same problem as having an effects loop that doesn't make good contact, cleaning the switching jack would be the repair for that. All jack soldering connections should be checked if they are circuit board mounted.
     
  5. NoahL

    NoahL Member

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    A couple notes, guys. No effects loop and, since this is the early 5005, no headphone jack, either. Just the High and Low inputs, no other in/outs. I mean pretty much 0 sound until you get to 5 or higher. Maybe at 4 you can hear the barest whisper of sound, but not much. It feels like there IS a taper, but but it's a funky one, with minute increases until 5, whereupon it ramps up quickly. Same on either channel, and same with all the pots (volume and gain and whatever guitar's volume I'm using). For a cheap amp, I won't mess with taking it to a tech unless you guys think there'd be an improvement in tone in having the question resolved.
     
  6. PRNDL

    PRNDL Member

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    Maybe try spraying some cleaner into those volume pots.
     

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