Boss MT-2 Metal Zone mod for clean EQ/boost pedal

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SAMBER_DINO
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Post by SAMBER_DINO »

First post here. I couldn't find a transcription of Brian Wampler's recent mod to the Boss MT-2 Metal Zone pedal to bypass the heavy distortion stages of this beast and turn it into a decent EQ pedal/clean boost.

Apologies if it has been posted already but I thought others might want to polish this turd too.

The mod is last 3rd of his video here:


So what you'll need are :

* one small jumper
* a 1" to 2" wire,
* a 1k resistor
* two .22 uf (224) capacitors
* and two 1 uf (105) capacitors


Now you'll need to :

Remove C35, R53, Q10
Replace C34 with a .22 uf cap
Replace R44 with 1K resistor

Remove R42 , C31

Replace C29 with a 1 uf cap
Replace C33 with a 1 uf cap as well

Remove D3 and D4
Remove R31

Remove C25, R36, Q8
Replace C24 with a .22 cap

Remove C20
Replace R30 with a jumper

Remove R14
Lift the end of R33 going to the removed diodes (left side of board as looking at the components side) and jumper it to the left side of R14 as looking at the component side of PCB, e.g.

mt2eq.jpg
I'll be working on this relatively simple mod later this week, and if it goes well, I'll show Wampler some love and maybe actually buy one of his pedals, lol.


Looking forward to other folks' progress and stories on this project.

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bmxguitarsbmx
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Post by bmxguitarsbmx »

These mods are mediocre at best. Brian even admits it. Much better to start with a simpler circuit and perform a mod that creates a pedal you will use. Anyone who has done these mods with fantastic results, is free to correct me. Just my opinion.

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SAMBER_DINO
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Post by SAMBER_DINO »

bmxguitarsbmx wrote:These mods are mediocre at best. Brian even admits it.
Thanks a lot, Wampler. Guess who's not buying one of your pedals now, jerk. Good luck sending your kids to college now!

In all seriousness, the demos of the EQ in the vid I linked to are pretty solid, certainly good enough for me to use to tweak a few fuzzes I have. I need a project to work on and picked up a new-new Metal Zone for $30.

I'll see. I've only barely even taken the board out of the chassis, so maybe it will suck ass. Who knows? Mileage varies.

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bmxguitarsbmx
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Post by bmxguitarsbmx »

ha. go for it. The mt-2 is a horrible, useless pedal... doesn't mean a modded one will be useful though. As I said, just my opinion.

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scoop
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Post by scoop »

Shoot, I'll definitely have a look at this tomorrow!! I actually had the idea to mod a couple MT-2's for EQ ONLY... but I never figured out how to get the boost part in there.

One minor caveat about this I have learned is the EQ section does NOT start out at neutral. If you put all knobs at noon there is an odd curve that is hard to dial out completely but it still makes a really great semi parametric EQ pedal.

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Post by scoop »

bmxguitarsbmx wrote:ha. go for it. The mt-2 is a horrible, useless pedal... doesn't mean a modded one will be useful though. As I said, just my opinion.
but its an eq pedal now. very useful. you ding your head on a bike lately?

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Post by bmxguitarsbmx »

scoop wrote:
bmxguitarsbmx wrote:ha. go for it. The mt-2 is a horrible, useless pedal... doesn't mean a modded one will be useful though. As I said, just my opinion.
but its an eq pedal now. very useful. you ding your head on a bike lately?
I've clearly triggered both of you. Being supportive is more important than being honest? Those are lame mods... I would be surprised if you found otherwise. Anyone with differing opinion? I'm not trying to start any beef, I'm trying to be helpful (believe it or not).

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Post by EmmG »

scoop wrote:.. EQ section does NOT start out at neutral. If you put all knobs at noon there is an odd curve that is hard to dial out ...
Maybe bypassing those 3 gyrator stages pre EQ will help. I've modded 4 metalzones, each a little differently and it can sound great. Why wouldn't it? Also having a ready made parametric EQ already there just waiting to be isolated is cool.
I'm speaking as someone who has people just give me these things for free.

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Post by bmxguitarsbmx »

For your consideration, here is a pdf of the basic mod I started with. I'll do my best to find the working copy with my hand written final values that might be deemed V1. Basically, I'm lowering Q values and changing resonant frequencies.

This is a complex pedal. It's easy to get bad sounds of it and it's hard to mod good sounds into it. As an amp tech, I deal with an awful lot of poorly done modifications to both amps and pedals. It's a real time waster, but I try my best to see these things through to become useful tools for music creation once again. Most of the horrible mods I see came off ebay with no disclosure of any modifications done. Often, the seller doesn't even realize he/she is selling a modified piece of gear.

cheers
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Boss MT-2 BMX Mod v0.1 preliminarys.pdf
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Jan1966
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Post by Jan1966 »

bmxguitarsbmx wrote:For your consideration, here is a pdf of the basic mod I started with. I'll do my best to find the working copy with my hand written final values that might be deemed V1. Basically, I'm lowering Q values and changing resonant frequencies.

This is a complex pedal. It's easy to get bad sounds of it and it's hard to mod good sounds into it. As an amp tech, I deal with an awful lot of poorly done modifications to both amps and pedals. It's a real time waster, but I try my best to see these things through to become useful tools for music creation once again. Most of the horrible mods I see came off ebay with no disclosure of any modifications done. Often, the seller doesn't even realize he/she is selling a modified piece of gear.

cheers
Tel more. Enrich us with your knowledge.

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Post by bmxguitarsbmx »

too kind Jan1966. I'll do my best to follow up :)

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Post by indyguitarist »

well, whatev's :)
The mods were posted as fun, not as a be-all end all. The mt-2 isn't that complicated, it's a basic analog distortion pedal with a fun EQ. Just bypass the distortion, making it a buffer before the eq.

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Post by bmxguitarsbmx »

..then ebay it.

(take it to a blues jam first tho)

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