Avenson Audio

MN-50 Smash Compressor Colour


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Sometimes you need a compressor to smooth the dynamics of a track in the cleanest, most transparent way possible. The MN-50 is not for those times.

The MN-50 is an aggressive, grabby, dirty compressor that colors everything it touches. It excels at smashing drum room mics into oblivion and turning peaky bass tracks into a thick, flat lines of crunchiness.

To create this compressor Colour, Avenson Audio upgraded the built-in, FET compressor circuit of the Fostex MN-50 mixer. The MN-50 mixer has long been a "secret weapon" for colored compression but were marred by a lack of makeup gain and unbalanced I/O. Avenson's MN-50 corrects the makeup gain issue, adds "high" and "low" input gain options, and benefits from the Colour format's balanced I/O.

Note: As will all our PCB projects, it's a good idea to check the availability of parts in the Bill of Materials before ordering.


  • Adjustable release
  • "High" and "low" input gain selectable via solderless jumper
  • Compatible with the Colour format

The MN-50 is offered fully assembled and tested by Avenson Audio or as a PCB only with accompanying BOM and assembly instructions.

Customer Reviews

Based on 5 reviews
Dag Rosenqvist

It sure does what it says it will do: smash! So far I've used it on acoustic guitar, drums and vocals and I really like what it does. You can either go all in effect wise and use it as an insert to absolutely destroy things, or for more subtle (well, everything's relative right... ) effect use it in parallell. Great and cheap, would definitely recommend this!

Dirty as hell but in a good way

The direct competitor to the MN-50 Smash Comp is the LTL Implode. Compared to the Implode, it's much less fiddly and maybe a touch less crazy than the Implode at slower release settings. However, once the release goes down, fidelity goes out of the window quickly in a cool way.

Technically, it's not as "clean" as the Implode -- it does 0.5 to 1% THD when not doing much, and upwards of 5 % THD when it's doing something.

Thankfully, the opamps in the new colour I bought are now socketed so the '70s opamps can be replaced with modern ones. I've switched to an OPA1642 and an OPA1612 without any effect on the THD -- I just don't like '70s opamps.

One of the best colour modules to have.

Matt E
A blast of smash

After building around 12 Colour Modules (complete kits) I decided to buy this PCB (two of them) and try to source the components. It took longer than I thought it would to find all of the parts, but that was part of the fun. I probably saved around $40-50 by building the pair instead of buying an assembled pair.

One of the two fired up right away (sounded great!) but the other had some odd noise at first. I checked and a couple solder joints did not look filled. After touching those up I tried again and the noise was gone.

It's a great sounding module and it was a good test of my skills. I recommend the MN-50 Smash to intermediate builders who want to test their skills.


A new all-time favorite here. My new secret weapon. I'm hosting them in a LTL MrFocus, and with the blend and extreme crush of the Smash colour module, it's exactly what I need for a heavy Kick / Stomp oriented group of bluesy songs. An instant transport back in time 60 years!

Really fantastic work Aversion!!! My only problem is that now I need at least 2 more... heh heh

Ross Halden
A great crush-compressor

For a small board with quite a few components I found these very easy to build, and I had a pair working perfectly first try after a couple of hours soldering. They absolutely nail the character of the MN50, I love them! Very quiet, and perfect for crushing drums with a fixed fast attack time. The audio examples here on the DIYRE site (usually very good) don’t really do justice to the variety of sounds you can get out of them. You can hear an MN50 up against some other compressors here: https://www.gearslutz.com/board/2746262-post171.html

The release control is faithful to the original, and goes from a very fast 50ms to 1 sec. I found the fast times far more useful than the slower settings (which sound more like a ducking effect) so I decided to get in touch with Avenson Audio to ask about changing the release pot value. They were very helpful, and suggested I changed out the 500k log pot for a 100k lin pot. That was a major improvement - now the release time can be more finely tuned, and also matched on two modules for stereo operation.

I also tweaked the input pad, as in my system I found the module to be compressing too hard too early, and I would have to pull back my sends by a good 6dB or so. So I contacted Avenson Audio again, and with their advice changed R3 from 3.6K to 820R. This inverts the pad jumper, meaning that the low setting gives around 14dB attenuation and the high setting gives around 20dB attenuation, which gives the drive knob far more range/control.

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