Short in EHX Bass MICRO Synth?

EDIT: I’ve been calling this the bass MONO synth, but it’s not – it’s the bass MICRO synth. The mono synth is a totally different EHX product, which I no longer own.

Before I go complaining to the seller (in another province), the manufacturer, or my local music store, I’d like to describe a problem to you fine folks and see if I can come up with the most effective way to explain it to any of the above. Thanks in advance for any suggestions!

The last couple of times I played with my EHX Bass MICRO Synth pedal (purchased new, only about a year old, light duty, never leaves home), it has produced popping sounds - always at the beginning and end of riffs or passages, and sometimes (but less often) during. These pops (about 1-3 at a time) sound like touching your fingertip to the end of a headphone cable, only louder. Hence why I think it’s a short somewhere in the pedal. Though I suppose it could be a tracking issue, too, since it’s a synth pedal & all. Either way, these popping sounds ruin the experience of the pedal, since it’s home of my favourite dark, warm underwater-dub bass sound (among others).

Things I’ve checked so far:

  • No issue on bypass, only when the pedal is engaged
  • Issue persists when the pedal is at the front of the chain (just this pedal and my amp)
  • Issue persists with different patch cables
  • Issue persists regardless of the number of pedals in my signal chain, or their order
  • Issue persists with various basses
  • No such sounds are coming from any of my other pedals
  • No daisy chain; using an independent power supply (the one provided with the pedal) plugged into a good surge protector
  • No snaps or pops if I gently wiggle the in, out, or 9v ports on the pedal-- only when I play
  • No snaps or pops when moving the sliders on the pedal
  • Pops at beginning/end of passages occur anywhere on the neck/at any frequency
    *Mid-passage pops seem to occur more often higher on the neck, once I’m well beyond bass territory

OK, those are all the details I can think of. This is SUCH A BUMMER as I just got my pedal board put back together after having my Light Pedal replaced due to a sound leak. So many moving parts!

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I have a C4 Synth pedal and I’ve got to be very careful because depending on the patch I use it can easily overload the amp really badly if not careful with gain staging.

  1. Do you have an amp that indicates if you are clipping? If so is it?
  2. Can you lower the output (level) of the pedal and make the issue go away?
  3. Can you lower the input (bass volume/output) to the pedal and make the issue go away?

You can also call or email EHX and ask their opinion and if faulty I bet they make you whole.

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Glad you got this resolved!

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So true. Pedals can be a very deep rabbit hole. :rofl: :rofl: :rofl:

How many pedals are on your board?

Too many! A dozen maybe? :rofl:


Thanks! It took some convincing and I had to insist the shop staff try it out for themselves on a kit in house… because their repair centre sent the pedal back saying it worked perfectly (i.e., “bass lady is full of :poop:”). Once they heard the problem themselves, they just replaced it for me and sent the original back to Gamechanger.


I don’t have an amp that indicates clipping, but this happens even at VERY low volume, like just barely touching the strings, and doesn’t seem to be any worse if I play harder or louder… and is worst at the beginning and ending of passages, regardless of their volume. But I’ll run a few more experiments today, because I haven’t been looking for this deliberately. Thanks for the idea!

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Fresh update - unfortunately not good news. The same snapping/popping sounds are present in 100% of the following situations:

  1. bass set at lowest possible volume that the synth pedal will register + volume attenuator pedal between synth and amp, set to low output;
  2. bass and synth pedal plugged directly into our mixer, which is a huge beast you could use for a show (tried various levels in the specific channel as well as master)
  3. With ALL (all!) sliders on the synth pedal pulled down to 0 – no bass sounds or synth sounds coming through, but I do hear all the same snaps and pops :open_mouth:

So the snaps and pops are coming through regardless of how I set input or output gain or volume, regardless of whether my out is my amp or a mixer, and regardless of whether the synth pedal itself is set to 0 while engaged. Snaps and pops are getting through from the pedal in all cases, unless the pedal is bypassed.

IMO, this is looking even more like a short in the circuitry of the pedal. Would you agree? Anything else I should try?

I’ve also emailed the seller (the wonderful Scott at Axe and You Shall Receive) and he’s great, so I’m sure I’ll hear back Monday at the latest.



It could also be an input/output connection plug issue. The snap and pop sounds kinda similar when you plug the bass in an powered amp. You could try something like contact spray to see if that works. I would just ask for a replacement anyway. Normally this should not be happening.

Hope you get it sorted!

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Oooh. Is either the i out or output Jack nut loose?

Sounds like it needs to go back for replacement.

It’s kind of surprising how many issues I’ve had with pedals in the last two years. Bad QC I guess.

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This is not going to help you, but thought I’d mention that I have a similar issue with the auto-swell feature on my Meris Mercury 7. (The auto-swell is like an automatic volume pedal. It detects when you pluck a string, immediately mutes the output, and then gradually increases the volume back to 100%, creating a swell effect.) I get a loud pop every time it mutes the signal, but I can work around it by completely muting the strings before I pluck. I’ve contacted Meris, and they confirmed that this can occur with some basses. Fortunately I don’t care much about this feature, and can work around it if I really want, and like the pedal too much, so didn’t return it.

Anyways, something similar might be going on with your pedal as well internally. I’d send an email to EHX and ask them whether it’s a known issue, and whether they have a workaround or solution.

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Thanks! I gave the inputs and outputs a gentle wiggle while playing to see if that made a difference, and it didn’t. Wish I had contact spray for another test! But yes, I agree, it just shouldn’t be happening!

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Nuts aren’t loose, and there’s 0 issue if the pedal is in the signal chain but bypassed. And yes, looking like it just needs to be replaced.

I’m having worse luck with new pedals, too – glad it’s not just me.


Thanks! Very interesting, and that does sound similar - the snaps seem to start when the pedal notices and responds to the signal from the bass. This shouldn’t happen on a bass-specific pedal, on principle! I’m starting with the online store I bought the pedal from. Hopefully they’ll agree to a replacement. I’ll try EHX next. I’m hesitant to deal with them prematurely as it may mean moving packages across the border - always a nuisance.

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Another update. Just did some trolling around online and found a discussion thread about the internal gain trim pots in the bass micro synth (accessible by removing the back plate)… but these are factory-set for single-coil p-style basses… which is what I play! :clown_face:


I dearly love Electro-Harmonix - definity one of the best and most interesting “big names” - but rumor has it their QC has been spotty in recent years. Sounds like a replace.


Never been a pedal fan myself. I have two for Bass an inline tuner and the Zoom B1X4 that’s it.
I do have a Boss RC30 looper and tube screamer pedal but use them on my electric guitars mostly. :+1: