Russian Big Muff Pi DC jack

[Shroom]

I plan to add a DC power input to my black Russian BMP, and since this is my first DIY pedal project, I was wondering if any of you guys would be able to give me any tips. I'm going to try to make it so that the battery switches off when nothing is plugged into the pedal, so I'm going to need a stereo input jack in addition to the DC jack, right? Is there anywhere in particular that would be good to order the parts from? I was just going to use Radio Shack. Also, is there anything else you recommend I do to it while I have the thing taken apart?

Thanks 

[LucifersTrip]

I plan to add a DC power input to my black Russian BMP, and since this is my first DIY pedal project, I was wondering if any of you guys would be able to give me any tips. I'm going to try to make it so that the battery switches off when nothing is plugged into the pedal, so I'm going to need a stereo input jack in addition to the DC jack, right? Is there anywhere in particular that would be good to order the parts from? I was just going to use Radio Shack. Also, is there anything else you recommend I do to it while I have the thing taken apart?

Thanks 

I believe Radio Shack only has the solid metal DC jacks which will short in a metal box.
you need something like:
http://www.taydaelectronics.com/servlet/the-2154/DC-Power-Jack-2.1mm/Detail

your guitar will be going in and out of the stereo/mono jacks many times, so best to get higher quality ones. RS ones are medium quality.  best to get something of at least neutrik quality:
http://www.smallbearelec.com/Categories.bok?category=Plugs%2C+Jacks+and+Fittings

and:

[peps1]

yep, you will need a stereo jack and wire the power-supply ground to the sleeve lug and ring to PCB ground, so it will only conect then a jack is plugged in and bridging the sleeve and ring.

And here is how to add DC jack

[Shroom]

Thanks guys! So I actually opened up my big muff and checked out a PCB for the very first time, and I'm realizing I know less about how to do this than I thought.  I've managed to locate the V+ node (or whatever you'd call it) and the input/output of course, but from what I can tell it looks like the input jack is already stereo.

I included a couple pics of the thing. If you guys could give me any pointers I would really appreciate it.

http://img.photobucket.com/albums/v101/Malen/Img_0255.jpg
http://img.photobucket.com/albums/v101/Malen/Img_0254.jpg

[peps1]

here is a pick with the input, output, +9v and ground shown.

[Shroom]

Alright so I'm looking at this thing and the way it's wired doesn't match any of the diagrams you guys have posted. It DOES already have a stereo input jack, so all I need is the power supply. It looks like the sleeve of the input is connected to the battery negative, the ring is connected to the output, ground (with several other things along the way), and other elements of the circuit, and the tip is connected to the stomp switch. So do I need a direct connection from ring to ground, using a wire, or will the pre-existing path on the PCB suffice, despite being connected to several other things? 

Here is a pic with these paths traced out:

[ashcat_lt]

What I did in my green Muff was to just wire the DC jack to a battery snap "reversed" from the one that goes to the board and then snapped the two together.  If I ever wanted to use a battery, I can just unsnap my "adapter" and attach the battery.  I'm not sure if that's a viable option for you.

Whatever you do you will probably want a cap or two across the DC jack.  The Muff wasn't built to reject AC noise on the DC supply.

[sewage666]

Do you want to devalue your green Big Muff? I did! So I added the DC jack. Way easy. 
Photo documented here: http://doktorsewage.blogspot.com/2011/06/minor-muff-malpractice.html

Otherwise, get a Visual Sounds battery clip converter. Way easier.
http://www.visualsound.net/index.php/products/pedal_power_supplies/battery_clip_convertor

[wavley]

What I did in my green Muff was to just wire the DC jack to a battery snap "reversed" from the one that goes to the board and then snapped the two together.  If I ever wanted to use a battery, I can just unsnap my "adapter" and attach the battery.  I'm not sure if that's a viable option for you.

Whatever you do you will probably want a cap or two across the DC jack.  The Muff wasn't built to reject AC noise on the DC supply.

Exactly what I did, wired up a snap to mate up, threw a big ole cap from 9v to ground, and played some rock and roll

[Shroom]

Do you want to devalue your green Big Muff? I did! So I added the DC jack. Way easy. 
Photo documented here: http://doktorsewage.blogspot.com/2011/06/minor-muff-malpractice.html

Hey thanks! This was pretty handy.

Whatever you do you will probably want a cap or two across the DC jack.  The Muff wasn't built to reject AC noise on the DC supply.

What kind of cap are we talking here? Please excuse my noobliness

[ashcat_lt]

Oh, you know, something from the biggish electro drawer.  100uf or so will usually do it.  The bigger the better as far as noise performance, but you'll start to pull down your supply voltage a bit if you go too big, plus it just becomes physically too big to be practical.  It's also not a bad idea to put some smallish resistor (10R or so) in series with +9V to limit the "in-rush current" a little, though I don't think I bothered on my Muff.

[Shroom]

Oh, you know, something from the biggish electro drawer.  100uf or so will usually do it.  The bigger the better as far as noise performance, but you'll start to pull down your supply voltage a bit if you go too big, plus it just becomes physically too big to be practical.  It's also not a bad idea to put some smallish resistor (10R or so) in series with +9V to limit the "in-rush current" a little, though I don't think I bothered on my Muff.

Saweet! Thanks a lot

[Shroom]

Oh, you know, something from the biggish electro drawer.  100uf or so will usually do it.  The bigger the better as far as noise performance, but you'll start to pull down your supply voltage a bit if you go too big, plus it just becomes physically too big to be practical.  It's also not a bad idea to put some smallish resistor (10R or so) in series with +9V to limit the "in-rush current" a little, though I don't think I bothered on my Muff.

So when you mention the resistor, do you mean in series with the cap? I read in the wiki that throwing a resistor after the cap helps prevent popping, but I want to make sure this is right.

[wavley]

He means resistor in series with +9v with the cap to ground so

+9v-----~~~----|-----circuit
           100R   +|
                       = 100uF
                      -|
                       |
                       _ Ground

Please excuse my symbols, hopefully you get my drift

[Shroom]

He means resistor in series with +9v with the cap to ground so

+9v-----~~~----|-----circuit
           100R   +|
                       = 100uF
                      -|
                       |
                       _ Ground

Please excuse my symbols, hopefully you get my drift

Uuuh... 

[ashcat_lt]

Uhhh...

Here's a Rat:

The 47r resistor and 100uf cap right next to the DC jack illustrate what I'm suggesting.

[Shroom]

The 47r resistor and 100uf cap right next to the DC jack illustrate what I'm suggesting.

Oh ok. That's what I thought but I wasn't completely sure. Thanks a lot

[boog]

i did the same thing as ashcat, except i made it permanent (rewired the battery wires to the jack lugs, threw the battery clip in the trash). as far as the resistor and cap: i didn't bother (muffs sposed to be noisy, why would i quiet it?) but fr 'safety' purposes you can just solder the li'l resistor to the positive lug of the jack and the red wire from the board to it, and just solder the cap from one lug of the jack to the other (just make sure the negative side of the cap goes to the black wire).