Help modifying MXR Noise Clamp

[johnr]

I should preface this question by saying I'm a novice at electronics. I'm good at soldering and understand some basics, but that's about it. I've read posts on this board from time to time to better understand what's going on inside my gear, but this is my first time posting here.

My ISP Decimator G String started giving me problems, so I sent it back to ISP to check it out. They said everything looked good, but I still had all kinds of weird behavior from it (weird interaction with other pedals). Eventually, I ended up switching to the (much cheaper) MXR Noise Clamp. The Noise Clamp is pretty good (especially for the price), but one thing I really miss about my decimator is the amount of attenuation it had. The Decimator claims something around 60 dbv of attenuation, while the Noise Clamp only does about 26 dbv. As a result, when the Noise Clamp is "gating," you can still hear quite a bit of signal coming through.

I know most noise suppressors use fairly common layouts, so my main question is whether increasing the attenuation would just be a matter of changing out a resistor or if it would be something more involved than that.

If it's most likely just a resistor, should I post pictures of the circuit board here?

Thanks,
John

[PRR]

> most noise suppressors use fairly common layouts

Not that much commonality. Particularly the tricks to get cost down.

Need schematic to find clues. A quick Google didn't find a for-sure right schematic. Find one and we can go from there.

[Mark Hammer]

The biggest complaint people have about noise gates, regardless of brand, is that they tend to cut off the decay tail of a strummed string.  Given that noise-gates determine if there is a note or deliberate guitar signal to pass, based on the amplitude of the signal at the moment, the extent to which a noise-gate passes only everything that you want, and none of what you don't want, depoends on the complexity of the envelope detection.

And if the circuitry that determines whether there is or isn't still a string vibrating is too simple and inexpensive to surgically separate string signal from mere background noise, then the strategy us to simply let more throgh and not cut quite so much.  Yes, there will be more noise, but at least the string fadeout won't get chopped so badly.

I don't know much about the ISP unit or the Noise Clamp pedals' insides, but some gates can also include filtering of high-frequency noise in addition to partial gating of the entire signal.  That will improve the overall noise specs, but results in a more complex circuit.

[johnr]

Quick update on this... I thought it had been too long for me to return my Noise Clamp, but it turns out I was wrong. So I'm just sending it back. I bought a Decimator II G String and now everything is working the way I need it to.

Here's a litte summary of what I found in my noise suppressor testing: http://youtube.com/watch?v=hg5wFvjfgBA