# Wampler DOD 250 mods on PedalPCB Distortion 250



## cgreg714 (Sep 23, 2020)

Hey all,
  Planning to build my Distortion 250 this afternoon with the Grey Mod specs, but I was just reading the article mentioned in the Distortion 250 description about Brian Wampler's mods to the original DOD. In it, he mentions a mod that allows you to add a 1m audio taper pot that acts as a tone control. Is this something I can do to the Distortion 250 circuit, and if so, how difficult of a mod is this, and what would wiring this pot "in series" look like? 
 Thanks to everyone on the boards. You are all incredibly helpful.


----------



## Mcknib (Sep 23, 2020)

This is the tone pot mod from this article where he lists his favourite mods for the mxr distortion (same circuit)






						MXR Distortion Plus Mods
					

Mods that will take your MXR Distortion Plus to a bigger, meaner level




					www.premierguitar.com
				




C5 value would change to 2N2, find the side that is connected to ground it looks like the right hand side but continuity check to make sure

Wire one side of the 2N2 onto the board at the pad connected to D2 anode (left pad but again double check with your meters continuity test),  then wire  lug 3 of your A1M tone pot to the other side of the cap,  jumper tone pot lugs 1 and 2 together and wire lug 1 to the C5 pad that goes to ground

Make sure you insulate the cap legs you don't want anything shorting

It's not a difficult mod but can get a wee bit messy I'd personally do it on the underside of the board, the boards are double sided so you can solder either side

Something like this, using wire so it's easier to move around and position I'd build it up on the pot first then basically solder your 2 wires to the board one to the left C5 pad the the other to the right C5 ground pad as shown










With this mod all your actually doing is sticking a pot wired as a variable resistor between the cap and ground I don't know if you'll get a volume drop as you turn it and decrease the resistance to ground thereby dumping more signal to ground


----------



## cgreg714 (Sep 23, 2020)

Mcknib said:


> This is the tone pot mod from this article where he lists his favourite mods for the mxr distortion (same circuit)
> 
> 
> 
> ...


Damn duder.....talk about going above and beyond!!! 
Thanks for this......can't wait to dive into it tonight.
Quick question: what does the jumper between lugs 1 and 2 ACTUALLY do? I totally get that there can't be one just attached to nothing, but knowing as little as I do about circuits etc., I have to ask the dumb questions to understand for future ventures. Again, a million thanks.


----------



## Mcknib (Sep 23, 2020)

You can actually do it without the jumper but I always stick it on, you can just use lugs 2 and 3 

Your making it into a 2 pin variable resistor ie when you turn the pot resistance varies rather than being fixed like a normal resistor


----------



## cgreg714 (Sep 23, 2020)

Mcknib said:


> You can actually do it without the jumper but I always stick it on, you can just use lugs 2 and 3
> 
> Your making it into a 2 pin variable resistor ie when you turn the pot resistance varies rather than being fixed like a normal resistor


Gotcha. That makes perfect sense. Thanks again for the info.


----------

