# MXR GT-OD to ZW-OD mod



## JeffHenneman (Nov 30, 2011)

A while back I decided to add an external switch to my MXR GT-OD. If you are not familiar with this MXR has a switch on the inside on the GT-OD pedal to switch it to a ZW-OD. It was pretty easy. I used a mini switch that I already had. If I would have planed it out better I would of picked another switch. I will get to that at the appropiate picture.
Here we go:
On the top left of the pcb there was a switch, Sorry I have no pics of the original switch. I decided at the last minute to take pictures. You can see the three holes that are left.






This is the switch I used. There is was too much wire left. I cut a lot of it off. If I would have planned it out more I would have used a different switch. But I like the spot I put the switch in and the size of the switch. The small size made it a hassle to install.





Here you can see the spot I drilled the hole.





Now here is where it got messy. The case on this pedal is pretty thick. More so than any other pedal I have. I reallly like how tuff this pedal is. Ok, so I had to grind the hole on the back side for the switch to fit thru the hole enought to put the washer and tighten the bolt.





Here you can see the switch it place from the inside.





Here is the new switch installed and soldered





And here is the switch mounted and complete. Up it is switched to GT-OD, Down position it is ZW-OD





So how does it sound? Well, Stock It is my favorite boost pedal. I like it more than my maxon 808. It tightens the lowend with out sacrificing the thick sound. I feel the maxon looses too much low end compared to the MXR. The MXR does smooth the sound more than the Maxon, the maxon is more raw. Just my personal preference.

For the ZW-OD mode;
In this mode the mids are scooped more than compared to the GT-OD. It works really well with a marshall amp. I tried a DSL with it and that combo rocked. I have a marshall 1960B cab and when I ran various amps thru it, the ZW mode worked awesome. Once I ran it with amps on a few other cabs I prefered it in the GT-OD mode. I think mostly becasue of the mid presence. In that marshall cab and the dsl. Of course it also makes sense cause Zack W uses marshall amps.
Hope you enjoyed this post. Rock on


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## ExousRulez (Nov 30, 2011)

Damn thats sweet! 

You should do that for money for lazy people like me


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## capoeiraesp (Nov 30, 2011)

Excellent work man!
I've got a MXR custom shop GT-OD in the mail and will look into doing this mod myself.


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## Wookieslayer (Nov 30, 2011)

Awesome job dude! always wanted to try an MXR OD with my rig. 

Do you know if the MXR CL1 Classic Overdrive (only from GC) is the same as the GT-OD?


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## JeffHenneman (Nov 30, 2011)

Wookieslayer said:


> Awesome job dude! always wanted to try an MXR OD with my rig.
> 
> Do you know if the MXR CL1 Classic Overdrive (only from GC) is the same as the GT-OD?


 
I am pretty sure it is, in fact I posted this on Harmony central and the first one to responed said it had the same switch in his classic pedal.


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## JeffHenneman (Nov 30, 2011)

ExousRulez said:


> Damn thats sweet!
> 
> You should do that for money for lazy people like me


 
I wish I had the time. Its not hard at all to do this mod. Anything that doesn't use high voltage is easy to work on in my book.


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## Leuchty (Nov 30, 2011)

Very cool!

GT-OD is my favourite boost aswell.


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## Shask (Nov 30, 2011)

Sweet. I have considered doing this to my Classic OD. It has the same switch.


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## DraggAmps (Nov 30, 2011)

Yep, I did this on my Classic Overdrive. It's the same exact pedal. Same exact internals that they use for the GT-OD and ZW-44 are inside. It has a cheaper paint job but that's the only difference. Not a different circuit, not even a cheaper circuit board or components. They just rehouse the GT-OD/ZW. The reason there's a switch is because the ZW is just a GT-OD with I believe only one component removed. They flip the switch and then install the same exact circuit into the ZW-44 housing. Cheaper than designing a very slightly different whole new circuit board. I'm pretty sure the switch just removes a resistor.


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## Nick1 (Nov 30, 2011)

I asked MXR and the M-66 is the same as the GT-OD which is real close to the Wylde OD. The MXR Classic Distortion (M-86) is the same as the MXR Distortion III.


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## Bluesman86 (Dec 18, 2011)

Hello, folks! There's lots of articles on how to make an "MXR GT-OD to ZW-OD mod". I bought GT-OD a couple of days ago and I'm completely satisfied with its bluesy sound  I did know earlier that ZW and GT overdrive pedals share the same PCBs, but it was a surprise for me that there's a switch that changes the effect type. I wonder if anyone here happens to know what does that switch switches? I mean, if I have a DIY Wylde Overdrive (without that switch, of course), what mods should I make to it, to make it sound like a GT-OD??? Btw, I compared the GT in "ZW mode" with my ZW copy - and they sounded really like twins Thanx in advance!


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## vanhendrix (Dec 18, 2011)

Bluesman86 said:


> Hello, folks! There's lots of articles on how to make an "MXR GT-OD to ZW-OD mod". I bought GT-OD a couple of days ago and I'm completely satisfied with its bluesy sound  I did know earlier that ZW and GT overdrive pedals share the same PCBs, but it was a surprise for me that there's a switch that changes the effect type. I wonder if anyone here happens to know what does that switch switches? I mean, if I have a DIY Wylde Overdrive (without that switch, of course), what mods should I make to it, to make it sound like a GT-OD??? Btw, I compared the GT in "ZW mode" with my ZW copy - and they sounded really like twins Thanx in advance!



I've never heard of anyone actually comparing them back to back, thanks for that! I would also like to see how the current zw pedal compares to that boss one that he was using before.


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## RonSwansonBacon (Jan 14, 2015)

Very interesting. Sorry for the necrobump from hell.


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## ridner (Jan 14, 2015)

the MXR M-66 OD has the same function


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## JeffHenneman (Jan 14, 2015)

ridner said:


> the MXR M-66 OD has the same function



That's nice to know


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## JeffHenneman (Jan 14, 2015)

RonSwansonBacon said:


> Very interesting. Sorry for the necrobump from hell.



Its all good, It was nice to see the old pics I took of this. I did a horrible job drilling out a whole for the switch, but then again I didn't have a drill press at the time.


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## Shask (Jan 14, 2015)

This is funny because I changed mine the other day on my Classic OD.

Always thought about putting a switch, but never have. I saw another idea also where someone just moved the switch to the other side of the circuit board so they could change it as easily as they change the battery.

I still take the lazy approach and use a bent paper clip to change it every few years, lol.


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## RonSwansonBacon (Jan 15, 2015)

Shask said:


> This is funny because I changed mine the other day on my Classic OD.
> 
> Always thought about putting a switch, but never have. I saw another idea also where someone just moved the switch to the other side of the circuit board so they could change it as easily as they change the battery.



That's a good idea too. I'm considering doing that to mine as soon as it arrives (just ordered it) and maybe even cut an opening on the bottom plate so I don't have to unscrew anything.


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