Members abceightsix Posted March 17, 2008 Members Share Posted March 17, 2008 I've heard you can change the output cap to a higher value to get more bass response. Can I wire a toggle switch to choose between stock capacitor and the new one so I can use the pedal for both guitar AND bass? Can someone show me how to do this? Any other suggestions? Thanks! Link to comment Share on other sites More sharing options...
Members zoomzilla Posted March 17, 2008 Members Share Posted March 17, 2008 Pics of the pedal wiring and the cap you want to toggle? Link to comment Share on other sites More sharing options...
Members abceightsix Posted March 17, 2008 Author Members Share Posted March 17, 2008 Pics of the pedal wiring and the cap you want to toggle? This is about all I can find on the net. I'll take pictures of my board as soon as I borrow a camera. It's the Sovtek Big Muff if that tells you anything. Link to comment Share on other sites More sharing options...
Members zoomzilla Posted March 17, 2008 Members Share Posted March 17, 2008 So are you saying you would need to change a bunch of them, or just one? Link to comment Share on other sites More sharing options...
Members nos Posted March 17, 2008 Members Share Posted March 17, 2008 I already typed out a nice description of what you'd have to do, but it disappeared into the mists of the intarwebs. So here goes again... **Edit: I couldn't get the image to embed properly, so see the next post. 1) Find the capacitor that I circled on your circuit board (if you can't find it, you'll have to post front & back pics of the board). Pay close attention to the way the cap is oriented. If you look at the cap it should be marked with a negative side, usually with a stripe with minus signs in it. You may want to mark the board with a pencil so that when you do the next few steps, you won't have any problems. 2) Remove the capacitor by desoldering it (google: how to desolder components). You can reuse it, but they are cheap and they don't last forever so I'd recommend exchanging it for a new one. 3) Time to get your switch ready. Make sure it is a SPDT toggle. It'll have 3 solder lugs. You'll also need both capacitors, your low value and high value. For the high value, I'd recommend 10uF. Put the NEGATIVE lead of one cap through the one of the outer lugs and position the body of the cap about 1/4" away from the lug. Bend the lead so it won't fall out. If you have 3 hands, you're lucky because it will make this a lot easier. Repeat the procedure for the other cap, ensuring you are soldering the NEGATIVE lead to the switch. 4) With the other lead (positive) of one of your caps, make a tight U shape. Get a length of wire that will be long enough to reach back to the PCB, plus a little extra. Strip one end and make a tight U with that too. Link the two U's together and twist them so they stay together. Solder the joint. 5) Do the same thing with the other cap, using the other outer lug. 6) Solder a third wire to the center lug. 7) If possible, bend the caps so that they are snug against the plastic sides of the body of the switch and wrap the whole thing in heat-shrink tubing or electrical tape. Immobilizing this whole assembly could save you a headache in the future. 8) Strip the ends of all three wires. Twist the ENDS of the two wires that go to the caps together so that they make one fat end. The middle lug wire goes in the hole where the POSITIVE side of the original cap was on the PCB. The other two wires, which you have twisted together, go into the hole where the NEGATIVE side of the original cap was on the PCB. Solder both joints. 9) Test it out. If it works, install your switch and you're done! Basically, what you've done is taken out the single cap and replaced it with two caps with a switch allowing you to choose which one you want to use, right? Let me know how it goes. Link to comment Share on other sites More sharing options...
Members nos Posted March 17, 2008 Members Share Posted March 17, 2008 Imageshack is pissing me off! Click on the attachment and hopefully you'll get it. Link to comment Share on other sites More sharing options...
Members abceightsix Posted March 18, 2008 Author Members Share Posted March 18, 2008 Thanks! I believe that is the cap I need changed. I I should have mentioned the markings on the photo were not mine, I found it that way. I'll try it as soon as the thunderstorms let up around this area. This kind of information is exactly why I joined this forum. There are a number of bass mods you can do to this pedal, I just thought this would be the simplest one to toggle. I may add a mid control pot later. If I screw either mod up, I'll let you know. Link to comment Share on other sites More sharing options...
Members abceightsix Posted March 18, 2008 Author Members Share Posted March 18, 2008 So are you saying you would need to change a bunch of them, or just one? There are a number of caps that can be changed, but I believe just changing the last output cap will give me what I'm looking for. Link to comment Share on other sites More sharing options...
Members abceightsix Posted March 18, 2008 Author Members Share Posted March 18, 2008 Okay, is this the cap I should be looking at? I believe the cap I want to change is non polar. How do I find the positive and negative sides? I apologize for the blurry pictures but my board is a little different. Link to comment Share on other sites More sharing options...
Members nos Posted March 18, 2008 Members Share Posted March 18, 2008 Yup, I would say that's it. The positive side is the side that faces the bulk of the circuit. The negative side is the one closest to the output wire. Link to comment Share on other sites More sharing options...
Members Prog Posted March 18, 2008 Members Share Posted March 18, 2008 Think about it: If only one (of four) feedthrough cap is changed, how will the bandwidth of the circuit be changed? The caps are in series. Link to comment Share on other sites More sharing options...
Members abceightsix Posted March 18, 2008 Author Members Share Posted March 18, 2008 Think about it: If only one (of four) feedthrough cap is changed, how will the bandwidth of the circuit be changed? The caps are in series. How would I switch the whole series of coupling caps? You can also take out the first pair of diodes to get more bass response, would it be easier to wire a switch to kill these diodes? I'm open to suggestion, please stop me before I f#$% it all up. Link to comment Share on other sites More sharing options...
Members abceightsix Posted March 18, 2008 Author Members Share Posted March 18, 2008 Okay, I want to make sure I'm getting this right, it's Russian and a little funky. I color coded the wires to make it a little easier. There are three lugs in the shape of a triangle on the back of the pots. If you're looking at the triangle with the tallest point being the top, the green wire connects to the bottom right of the volume pot and then a white wire (on the same lug) is wired to the switch. The yellow wire connects to the bottom left. And another yellow wire connected to the top lug is soldered to the switch. Link to comment Share on other sites More sharing options...
Members nos Posted March 18, 2008 Members Share Posted March 18, 2008 The switch in your picture... is that the switch you're going to add? Or the stomp switch? Link to comment Share on other sites More sharing options...
Members abceightsix Posted March 18, 2008 Author Members Share Posted March 18, 2008 The switch in your picture... is that the switch you're going to add? Or the stomp switch? That's the stock switch. I will be changing it to true bypass soon enough. I can describe it in greater detail if need be. Link to comment Share on other sites More sharing options...
Members nos Posted March 19, 2008 Members Share Posted March 19, 2008 Sorry I take so long to reply. My computer time seems to be in short supply these days. Anyway, you really shouldn't have to mess with the volume pot wiring at all. Leave all those connections intact. You're only going to interrupt the circuit where that cap is. If you look at the pic of the bottom of the board where you put a circle around the cap: Desolder the cap. After you have built your toggle-switch/2-cap assembly, run one wire from that upper pad on the board to the center lug of your switch. Run two wires (one for each cap) from the lower pad to the negative leads on your switch/cap assembly. That should take care of it. Any other ??'s, just let me know. Oh, BTW, you may want to change the input cap as well. Same procedure, except you need a DPDT (with six lugs) switch. The three other lugs are for the pair of input caps. Link to comment Share on other sites More sharing options...
Members abceightsix Posted March 20, 2008 Author Members Share Posted March 20, 2008 Making sure I'm looking at the right caps. I think those are the right ones, but can anyone with a Sovtek Big Muff confirm? Link to comment Share on other sites More sharing options...
Members nos Posted March 21, 2008 Members Share Posted March 21, 2008 Yeah, can't help you there. Mine's not Russian. Link to comment Share on other sites More sharing options...
Members nos Posted March 21, 2008 Members Share Posted March 21, 2008 Definitely go to the forum at http://www.diystompboxes.com They are very helpful diy'ers and effects junkies. I'm sure a bunch of those folks have Russian Big Muffs and have taken them apart. Link to comment Share on other sites More sharing options...
Members abceightsix Posted March 21, 2008 Author Members Share Posted March 21, 2008 I'm pretty sure I have the right caps, but I'll post a thread on that forum to make sure. I'll let you know how it goes. Link to comment Share on other sites More sharing options...
Members abceightsix Posted March 21, 2008 Author Members Share Posted March 21, 2008 So if I change those caps to .1uF for guitar, what value should I go with for bass? I guess I'll have to go higher than 1uF because those were the stock caps, but what value? I thought 22uF maybe? Link to comment Share on other sites More sharing options...
Members nos Posted March 21, 2008 Members Share Posted March 21, 2008 10uF or 22uF would probably do the trick. If you can figure out a way to test out some different values before you solder that would be ideal. For instance, make the wires coming off your board a little long and attach alligator clips to the ends. Hook those up to your caps. Test it out and when you've found what you're looking for, cut the ends off, strip and solder permanently. Link to comment Share on other sites More sharing options...
Members abceightsix Posted March 22, 2008 Author Members Share Posted March 22, 2008 Good idea, thanks. Link to comment Share on other sites More sharing options...
Members abceightsix Posted April 3, 2008 Author Members Share Posted April 3, 2008 Got the switch wired up, definitely a difference between caps. I went with .1uF for guitar and 10uF for bass. I think I may replace the 10's with 22's for a little more bass and add a mid control pot. The only problem I had was that I drilled the hole for the switch between the input and output jacks and the crazy Russian distortion pot's prongs interfere with the switch. Makes a high-pitched squeal. Instead of moving the switch, I think I'll just replace the pots with some that are a little less funky. Thanks for the help guys. I'll get some pictures when I work out the bugs and put everything back together. Link to comment Share on other sites More sharing options...
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