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[MXR M87 Compressor] Hiss!

Discussion in 'Effects [BG]' started by DieterVDW, Dec 3, 2013.

  1. DieterVDW


    Sep 19, 2012
    Gent, Belgium

    I just bought the MXR M87 Compressor, but for a quite exuberant spending (I think it's pretty expensive), I'm not very satisfied.

    There is a very noticeable hiss when using the compressor.

    I have 2 theories about this:

    1. The pedal is just plain broken.

    2. My bass output is just so hot that I first need to attenuate the signal A LOT using the 'input' control, and then boost it again A LOT using the 'output' control. In the process the internal noise of the pedal is also boosted A LOT resulting in a quite noticeable hiss.

    I'd like some input to decide which theorie is appliceable.

    If I manipulate the 'input' and 'output' controls so I DECREASE the compression effect until it is not noticeable anymore but the volume is equal with the effect on and off, I end up at the following settings:
    - Input: 9 o' clock, Output: 3 o' clock (so heavy input attenuation and heavy output boosting) => HISS!

    If I then slightly increase the 'input' setting to increase the compression, and decrease the 'output' control to remain at equal volume, the compression effect immediatly increases a lot. Input at 10 o' clock is already way too much compression for me when playing the low strings. (Although only max 3 leds light up.)

    It seems to me the root problem here is that my pickups are too hot for this effect? Result: way too sensitive controls and lots of hiss.

    When setting the 'input' and 'output' controls to 12 o' clock for example, the hiss is barely noticeable. However, then the compression effect is WAY too much for my tastes.

    Also the pedal seems to color my tone quite a lot: boosting the high frequencies. Not necessarely bad, but a lot more pronounced than I expected...

    My bass is a Yamaha BB425X .

    Compression-wise, my reference is a cheap Boss LMB-3 Compression/Limiter I've been using up until now.
    In comparison, it has no noticeable coloring, is dead-quiet and can be either suble or hard-limiting.
    For now, I seem to like the cheap LMB-3 a lot more :s .

    For a pedal double the price, I am currently disappointed in the MXR M87. I like the extra attack and release controls, but very much dislike the hiss and very pronounced effect.

    So, is this pedal defective?
    Or are my pickups way too hot and / or I am way too sensitive to the compression effect.

    I seem to be able to offset this problem by attenuating my input signal. For example if I use the LMB-3 with neutral settings and the level at 11 o' clock before the MXR, I get more controllable and subtle compression without the hiss.
    However, needing an extra pedal to attenuate my bass' signal is kind of a let-down.

    It would be cool if there was some kind of internal trim-pot to fix this, but haven't found any information about that yet. Don't think it exists?

    So any advice is welcome. I might return it...
  2. Hmm. I went from the LMB-3 to the MXR M87 because I noticed the Boss was colouring my sound (it reduced the highs).
    You may want to read the instructions on this. As I understand it, the adjustable knob with 4,8,12(?),16(?) knob is the only control which adjusts the compression setting. The 4 and 8 settings are compression and the next two are limiting. The manual will give you proper instructions on the input and output volumes but I found a nice compression with all the knobs (except the compression knob) set at noon. I've adjusted since but I found this pedal is to be very transparent.
    You can try my settings but would really recommend you read the manual for a better understanding. Output at noon, knob above it around 10:30, compression at either 4 or 8, Input volume at 12:30 and knob above it around 1:30.
    Good luck.
  3. BioDriver

    BioDriver A Cinderella story

    Aug 29, 2008
    Austin, TX
    Hmm... Mine's pretty quiet and I'm using a fairly hot output (Aguilar pups with an OBP-1 preamp). Have you talked to Dunlop about it? IME their customer service is ace.
  4. Vlad5

    Vlad5 Chronic Knob Twiddling Tone Chaser

    Feb 17, 2011
    New England
    Yeah, I'll chime in and say MXR customer service is top notch, good people over there.
  5. DieterVDW


    Sep 19, 2012
    Gent, Belgium
    Hmm I just think the effect is not supposed to be run with the 'input' so low -> hiss.
    Also when the 'release' and 'attack' controls are very high -> fuzz/distortion.

    But now I tried using the effect with more normal input level values, and everything seems to be better. I think I overreacted :) .

    Is anyone interested in sound samples on different settings? Or has that been done already?
  6. Phew! Hopefully then, money well spent. Enjoy and continued good luck in the ever eternal 'tone-search'.
  7. bongomania

    bongomania Gold Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    You might want to try another M87 at a local shop if they have one; or see if you know anybody local with one to try. I suggest this because there are many reports of individual defective M87's out there. Hiss is a common symptom. If you try another one, you can find out if it has the same sound and behavior as the one you bought.
  8. uk_bassist


    Dec 9, 2013
    London, UK
    +1 on the hissing M87 - really disappointing on a £150 stomp box. Returned mine today to Amazon. Might try the TLC as a replacement - not sure I want to risk another M87, just in case. This is my 1st post BTW, so hello all :)
  9. BioDriver

    BioDriver A Cinderella story

    Aug 29, 2008
    Austin, TX
    Howdy! You might want to know taht http://ovnilab.com is your friend. Welcome to the rabbit hole.
  10. uk_bassist


    Dec 9, 2013
    London, UK
    Thanks. Have already explored ovnilab's reviews - in fact it was the MXR review that prompted me to get this one. Have just ordered the TLC as replacement - we'll see how it stacks up. Also have put my name down for an FEA Opti-FET - bit of a wait though (Glen reckons 9 - 12 months :bawl: ).