MXR Noise Gate Build

[oldrocker]

I'm trying to build the NG.  I'm using perf and thought this would be an easy build but it turns out that this is one of the harder ones I've done.  I'm adding all the pots for attenuation, release and attack.  I don't have the right Jfet for it yet so I've been trying to test it using a MPF102 for now.  Testing with my audio probe I noticed and lot of distorted gain at pin 1 of the IC.  The signal only comes from Q1 and the threshold pot before going to pin 3. So is it normal to have such a high fuzzy gain coming out of pin 1?

[oldrocker]

I was wondering if anyone has built this pedal successfully using the latest mods from Tonepad.  I noticed a disclaimer stating that these mods have never been confirmed to work and verified.  I can't tell if the pots added for attenuation, release and attack is the reason.  I'm still trying to get this thing to work and I'm thinking of switching to the FIS schem using 2 741 IC's.  Both claim to be the MXR Noise Gate.  Has anyone tried building the 741 FIS version?  I don't see how removing the added pots would make any difference but I'll try that first.

[darron]

I was wondering if anyone has built this pedal successfully using the latest mods from Tonepad.  I noticed a disclaimer stating that these mods have never been confirmed to work and verified.  I can't tell if the pots added for attenuation, release and attack is the reason.  I'm still trying to get this thing to work and I'm thinking of switching to the FIS schem using 2 741 IC's.  Both claim to be the MXR Noise Gate.  Has anyone tried building the 741 FIS version?  I don't see how removing the added pots would make any difference but I'll try that first.

i tried to build the newer tonepad version last year. i didn't get it to work and havn't really troubleshooted (troubleshot?) it. read some of the comments on the tonepad website from people who have built it. if i remember correctly, some people said things were wrong but once they fixed it it worked. I didn't use any substitues and tried with and without the mods. basically my model's attenuation knob worked, but it would never actually 'gate' my tone. it seemed to add a tiny bit of extra noise also.

the box is actually infront of me as ive been using scraps from it. my issue may have been that i just made a dodgy pcb as it was one of my first. checking with a multimetre later one however, it looks reasonable.

i'd like to hear reports from other people

[oldrocker]

I would like to hear from anyone who perf boarded this pedal.  I see people who successfully made this work from an etched pre-made PCB.  Has anyone prefed it?  I'm wondering if the schem actually does match the PCB layout or is there a difference somewhere.  I doubt if that's the case but I would like to hear from successful builders and see what they found.

[RickL]

It's been a while since I built it so my memory may not be perfect but it was one of my unsuccessful builds. IIRC it never did gate and all I ever did get out of it was mild distortion. It's in my pile of "I'll get to this someday" along with a Phlanger and several other things.

[oldrocker]

Well I guess I have to live with the fact this will be the that I never got working.  With all my other builds I was always able to them to work to some extent even if they needed a little tweaking.  But I've been over this circuit at least a hundred times (I'm serious) and I've come to the conclusion that it's never going to work.  I really can't complain though.  After over 20 projects it's the only one that I poured my heart and soul in to I just can't get anything reasonable out of it.  I was going to break down and buy the PCB from Tonepad but I'm thinking that I'll just skip this one over and move on to something else.  I wanted a noise gate after the 280 compressor build to knock out the hiss when I'm not playing.  If anyone knows of a different noise gate circuit please write and let me know.  For now I'll strip this one down try something different.  Maybe a Tremulus or Peppermill.

[Fp-www.Tonepad.com]

email me your mailing address, I'll send you a pcb, on the house.

Fp

[oldrocker]

I would like to say publicly that I don't accuse Tonepad of not have legit schematics.  I'm sure this Noise Gate build problem is something that I messed up.  I was only wondering how perf boarding this project had worked out for others.  I guess it's a harder one to get right.  Tonepads nice offer shows the integrity of their company and I wouldn't want to discourage anyone from using the Tonepad website or their products.  Tonepad has done so much for the DIY Stompbox community and so I would take this opportunity thank them for their support and contributions.

[David]

Hey, OR:  Perhaps instead of a noise gate, you really need a quieter compressor?!?!

[Mark Hammer]

Even if you have to go surface-mount, the downward expandor function on the SSM2166 chip used for Jack Orman's Q&D compressor makes it worth the cost and effort, and far more predictable and reliable than most gating circuits I've seen.

As for distortion reported by MXR-NG builders, one of the followup letters to "Home Recording" magazine years ago when Jon Gaines published his noise gate project (http://hammer.ampage.org/files/GainesNoiseGate.PDF) there concerned buzziness and audible distortion.  Gaines noted that having too much envelope ripple in the rectified control signal, combined with a very low threshold and rapid time constants, would result in very rapid re-triggering/re-gating that would sound like distortion.  The solution lay in drawing out the decay/release time a bit more (which would have the effect of smoothing out ripple) and raising the threshold a bit.

I'm not saying this is precisely what people are reporting here, but just noting that people described it as "distortion" back then, because they felt that's what it bore the closest resemblance to.

[bwanasonic]

I wanted a noise gate after the 280 compressor build to knock out the hiss when I'm not playing.  If anyone knows of a different noise gate circuit please write and let me know.

The compressor has a built-in gate called the off swtch! I use a volume pedal last in my signal chain that I can use as a *manual* noise gate. It also functions as a mute switch when switching guitars, etc.

Kerry M

[oldrocker]

aghhh!

[Fp-www.Tonepad.com]

Please check the pinout of your FET, this is the most common issue with this build.

[darron]

all this talk makes me want to get mine going.... hmmm.... but then i'd have to re-buy all the parts that i took from it.

if anybody has some pics of the pcb and/or enclosure i'd LOVE to take a quick look for comparison. i didn't substitute any parts

[Incubus]

I tried making one of these on perf.

All I had was trouble, and I never got it to work correctly.

Replaced fets, tried different zeners, checked, re-checked, re-re-checked and re-re-re checked the tracks on the board, no luck.

I went crazy with it and eventually gave up.

[oldrocker]

I heard that.  All I can say is if you decide to perf this project you better have nerves of steel and lot of time on your hands that you can afford to waste.  I've gone to the point of taking my perf board apart and re-routing components to match the schem to no avail.  I've twisted transistor pins between gate and source I've even replaced caps on the off chance that they were bad and nothing works.  I'm done now.  I can do no more.  I think ordering a PCB from Tonepad may be the only way to make this circuit work.  I can't believe I've finally been beat.  I never gave up on any project until now.  But I chalk this one up as my first failure but I'm sure it won't be my last.  Even with the frustration it's still been fun but I have to move to a stompbox I know I can get working.

[fretzburner]

Built from tonepad version 1 layout and it works but made some small changes.the 10uf to fet reversed the polarity,changed output cap to 10uf,1uf parallel to 100k changed to .01uf.It's working but i noticed a slight delay on gating action.i can still hear the noise maybe a second before it closes.Is this can be adjusted by release pot mod?and the gating action is not smooth(decay of the sound when gate is in action).