MXR Micro Amp

Discussion in 'Effects [BG]' started by BassOliverB, Dec 28, 2013.

  1. Hi guys,

    I bought a MXR Micro Amp as a boost pedal. (The reason I chose that specific pedal was that Flea also uses it) But it seems like it can't handle the input signal from my Modulus. No matter how much gain I add or remove it buzzes - but almost only when I use the E string.

    I thought it would be a great idea to use it since it works with Flea's bass.

    Any suggestions to how to fix the problem?

    The only reason for why I think it works with Flea is that Flea uses Wireless units, which might have a lower output compared to using cables.

    // Oliver
  2. Turtle71

    Turtle71 Supporting Member

    Aug 11, 2009
    Madison, WI
    I use the micro amp to boost the level of my stock P-bass up to the same level as my 1/4lb equipped P-bass, it does the job wonderfully with virtually no noise.

    I've also used it as a boost into my dirt pedals, I've used both passive & active basses, as well as 4 & 5 stringers, I've not experienced any of the noise you are having.

    It's possible you got a dud?

    I'll assume you've tried it with other basses to confirm there's not an issue with the Modulus? Excellent basses, so I doubt the problem lies there.

    I don't know much about the Modulus Flea bass, active preamp? possible dying battery? I've had bad/dying batteries give all sorts of weird noises & such.
  3. Well...why are you trying to boost?

    The Micoramp only has 7 volts or so of headroom and has potential to boost way beyond it's power limits.

    If you're bass is hot already then you don't have much room to boost before it hits the power limits and starts clipping.

    What are you boosting into? That could also be clipping if it can't handle the size of your now boosted signal.

    The Microamp is just your bass louder and really shines into overdrives or tube amps or for solo breaks.

    If you're just playing cleanly then it's better to use the input gain on your amp for more volume and kick on the microamp when you need juts a little bit more volume for a impact on a particular riff or such.

    It also has some nice buffering qualities so it is great to have in front of a long signal chain.
  4. Yes, I have also tried to use a Sterling by Music Man Ray 34. I got a tiny little less distorting effect with that...
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  6. Turtle71

    Turtle71 Supporting Member

    Aug 11, 2009
    Madison, WI
    Excellent point.
  7. The reason for why I have the boosting pedal is when I want to turn up the volume for soloing fast, without having to stop, turn around and add a little bit of volume from the amp.

    The signal from the Micro amp goes directly into my GK amp. And there is no clipping on the amp.
  8. There's something wrong with your pedal. Get it looked at. I use a Micro Amp on a regular basis with a variety of basses (including a Modulus 6) and have never heard any hint of distortion or noise.
  9. Hmm, the pedal is not old, I bought it in July or August. So too bad if the pedal is already broken.
  10. Turtle71

    Turtle71 Supporting Member

    Aug 11, 2009
    Madison, WI
    Well, if that's all that's in your signal chain, and we'll assume the battery in the bass (if equipped) is up to snuff, then really all it can be is the pedal.

    Drop into your local music store and try another one out, assuming you've got a store near by that actually has one in stock :meh:
  11. Turtle71

    Turtle71 Supporting Member

    Aug 11, 2009
    Madison, WI
    If purchased new, it's should be well within it's warranty period, my personal experience with Dunlop/MXR has been excellent when it came to warranty issues or other customer service inquiries.

  12. Good idea.
  13. But we all agree that the Micro amp requires 9v and 100mA, right?
  14. Turtle71

    Turtle71 Supporting Member

    Aug 11, 2009
    Madison, WI
    Ya' Know, I've never really given it any thought, I just power mine with my Voodoo Lab PP2+ and go.

    It is indeed a 9V pedal that much I do know, but what it's amperage draw idea. :(
  15. Jazz Ad

    Jazz Ad Mi la ré sol Gold Supporting Member Supporting Member

    Many GK amps have a footswitch for the boost knob. Which model do you own ?
  16. My vote is still on clipping. Does it buzz the whole turn of the knob?

    Is the buzz responsive to your playing?

    Or is it like a hum sound in the background?
  17. The buzz/distorting effect is there when I play hard on my E String. But it isn't there when I roll of the volume on my bass. The buzz is there probably only because of the input is too hot. But I still don't understand why Flea can use it without buzzing/distorting effect...
  18. BTW my playing style is just like Flea's.
  19. Turtle71

    Turtle71 Supporting Member

    Aug 11, 2009
    Madison, WI
    Well, we have to go on the grand assumption that Flea's version of the Micro Amp is stock, and not somehow modded to taste.

    That being said, it does sound like your driving the input too hot, but like I said I've driven mine with a really hot input as well (Tobias Growler 18V preamp...plenty of juice), and I don't clip my pedal at all...even at FULL volume on the bass.

    Try another one, see if it's the same result.
  20. willbassyeah


    Oct 9, 2011
    if its only the E string, it might be your pickup height?

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