MXR Schematics

[adding_to_the_noise]

I'm building an MXR Distortion Plus and was wondering if the schematics i had are correct. I read in the forum about a guy who had a problem with the wiring on the input jack. Is the ground connected the right way or does it need to be switched around?

http://www.diystompboxes.com/pedals/MXRDIST2.GIF

[petemoore]

Yupp, Schematic is correct...

[Mark Hammer]

Some stereo jacks are easy to visually decode (i.e., THAT's the solder lug for THIS contact), but others less easy.  Making mistakes with the wiring of the stereo input jacks needed for battery switching is not uncommon.  This is especially tue if you get accustomed to one brand/type and switch to another.  Not every manufacturer lines up the lugs in exactly the same order, unfortunately.  Just be careful, confirm the lug-to-contact path with a meter, and you'll be okay.

And just to avoid any confusion in the future, while the file you link to is called MXRDIST2.GIF, the Distortion II, also made by MXR, was a much more complex 4-knobber that came in what might be called the second wave of MXR pedals in 1590BB-sized boxes.  It should not be confused with the Distortion Plus.

[adding_to_the_noise]

I've got another question about the jacks. I understand that one is ground and the other is signal, but what do i need the stereo input jack for? What does the other ring connect to? Also i'm having a problem wiring my switch. It's a DPDT and i'm using one side for the input out put and the other side for the LED. I've had to change this because the input to the board was absorbing the signal too much, is there a way i can wire the true bypass and still have the LED with a DPDT?

[octafish]

The stereo socket acts as a switch in the earth connection switching off the effect when no cable is plugged in. It's so simple I often forget just how brilliant this is.

Re: the DPDT plus LED
There are two ways, "millenium bypass" and the analog alchemy led trick. If you're working with vero there are millenium bypass layouts in the layouts gallery. Google "millenium bypass wrappers" you should find what you're looking for, (its out there somewher can't remember where) or alternatively go to http://www.diystompboxes.com/analogalchemy/index.html and click on LED trick

[adding_to_the_noise]

Thanks for the link, i'm pretty sure that many people have used this and it works but i'm having a little trouble understanding the led part of the schematic. Since the Led is connected to both V+ and ground, how does the transistor control whether it is on or off. Sorry I'm new and i don't understand much about transistors

[adding_to_the_noise]

Thanks for the link, i'm pretty sure that many people have used this and it works but i'm having a little trouble understanding the led part of the schematic. Since the Led is connected to both V+ and ground, how does the transistor control whether it is on or off. Sorry I'm new and i don't understand much about transistors

[octafish]

Transistors do two things basically (I really dont know much about transistors either), they either amplify, or they act as a switch, in this application its working as a switch. Yesterday I tried a rat style bypass retrofit to my diy blue box. I found this one at AMZ (link at top of page) with an explanation of how it works in the Lab Notebook section. (full of great stuff). I got this working straight away, I had to tweak the LED trick a little.

[adding_to_the_noise]

Ok, I'ev finished building the stompbox, but it has a few problems. The distorted channel is not as loud as the clean channel and there is no distortion. Are these common problems?