• Date JoinedApr 16, 2009
  • Total Views109,489
  • Featured %66%


Hello Mr.Scmidtn, long time no contact. Finall i've repair my DS-1. I have a class starting from the August so I checked my DS-1 after I have a quite long holiday right now. I realize that my problem in my DS-1 is the joint from my caps. I don't know why the joint affected my DS-1. But, after I re-soldered my caps, it began to work. I'm glad my DS-1 functional again. Ohy, now I'm concentrate in modding my SD-1. I've done a lot of mods & still searching. Have you ever mod the SD-1 ??
Schmidtn (author)  djajasoekarta7 years ago
Good, I'm glad to hear you've got your pedal fixed and are back to making music. No, I have never moded a SD-1. I don't own one, but from what I've seen online people like buying the cheaper SD-1 and moding it to sound like an old Ibanez Tube Screamer.
Oy, I have a questions,in DS-1 mod, there's a 47pF cap soldered parallel with diode (D5). My questions : 1. What is the purpose of this cap. 2. How much it affects the overall sound ?? Thx
Schmidtn (author)  djajasoekarta7 years ago
I believe the capacitor acts as a check and balance for the circuit, but I'm not 100% sure. I believe it passes the signal through the capacitor when there isn't enough electricity flowing through the circuit to trigger the clip from the diodes (which is why it's in both circuits). So when you have your pedal on and not actually playing your guitar it doesn't get a bunch of feedback through the circuit because it has that filter on it... capacitors are used a lot to to filter out interference.
Hello Mr.Schimdtn, Long time no communicate. I got a new problem. It’s still about the Keeley mod Boss DS-1. When I put a LED in D5 as shown in the instruction, it doesn’t light up. What cause this problem ?? I just make an ASE mod, there’s still no switch, just a LED in D5. Is the 47pF caps across the Clipping Diodes cause this ?? I’ve checked the orientation of the to make sure it put correctly. Thx
Schmidtn (author)  djajasoekarta7 years ago
Two things could cause the LED in D5 not to light up; 1) the LED is in backwards... make sure you check your LED's polarity or 2) the forward draw of the LED is too large and you need a different LED with a lower forward draw (anything lower than 2.0V should work, but 1.75V is optimal). The switch goes in D4 and either jumps the circuit to through the D5 mod or routes the circuit through the D4 mod so flipping the switch changes the LED the current run through and changes which mod you're performing. The capacitor sort of confuses me, but it seems to be active in both circuits so I think it's used to help make the clipping sound the pedal gives you when you use it. The 47pF capacitor could only not help your diodes if it wasn't all the way soldered to all four pads of the diodes.
I've check the polarity. It's right in the place. I use the stock LED like the instruction's recommendation. What do you mean about forward draw ?? I don't use a Bright LED.
Schmidtn (author)  djajasoekarta7 years ago
All LEDs have a forward draw labeled, "Vf," for Volts forward. For an LED to light up you have to use Ohm's Law (which is the equation I've already provided you) and forward draw will affect that equation. If you're sure it's a good LED (IE: not burnt out) and you're sure you have your polarity correct and you're sure you have enough resistance in front of it in the form of a resistor of sufficient resistance value... and it still doesn't light up then I think there's something else wrong with your circuit somewhere else and not in the LED.
Mr. Schmidtn, I finally revealed the problem. I’m wrong in putting the LED !! Hha, I’m so sorry Mr.Schimdtn for making this problem becomes difficult. It’s quite a big mistake for me. The problem is, the cathode/anode in my LED has a reverse position than my ordinary LED. I wonder why this could be happen in production. Is there’s no standard in putting the cathode/anode side of the LED ? I forgot to see the length of the lead. In my previous project, I always indicate the side by looking of the size of the electrode. Ordinarily, the bigger electrode inside the LED always be the cathode side but in my LED it’s the positive side. I’m confused with the production consistency of LED Finally my ASE mod is success. It lighted as I picked the string. But, I got a problem again T_T. When I connected the LED with cable, I soldered the back side of the PCB. When I soldered the PCB, I saw there’s a bad joint in other part. I soldered that bad joint & then continue to finishing my ASE LED cable. When I plug in the guitar, my DS-1 SOUNDLESS. There’s no sound from my DS-1. It’s LIGHTED but there was no sound. I checked the ASE LED, it only lighted up when I switch my pedal from On to Off. I’ve checked the cable, guitar & amp, no problem. I’ve tested my system with other pedal & it’s worked. My system has no a problem. I wonder there’s some problem on my DS-1. When I checked the joint (On the in/ou Jack, pot etc) there’s no problem. I wonder if this caused by my failure in soldering the bad joint which I found. I realize that I soldered the lead of the Transistor !! Is my prediction true ?? Is my transistor overheated. I’ve checked all of the cable inside the DS-1. There’s no problem. The main problem: Lighted but soundless. Thx
Schmidtn (author)  djajasoekarta7 years ago
Congratulations on getting it working... for a little while at least. Yes, some manufacturers do switch which side of the LED houses the flat face. They almost always tell you on the back of the package whether anode or cathode is flat though. Just important to keep your polarity straight. I'd say you might have damaged the transistor (hard to do, they can take a lot of heat) or you may have shorted the circuit when you fixed the joint. Check that solder pad and all of the pads near it to make sure you didn't short it somewhere, that board has a lot of tight places in it. Quiet a lot of realty in a small space.Just put everything back to the condition it was in when you had it up and working.
I looked at the PCB. I don’t saw any short circuit. The transistor which I actually soldered is Q7. I’m sorry Mr. Scmidtn, I don’t know to read Circuit well. According to your view, is this caused my case, ‘Light but not have a sound’. When I looked into the schematic, I saw that this transistor located before output transistor. Thank you for your attention
Schmidtn (author)  djajasoekarta7 years ago
Check the voltage both before and after that transistor, it could be restricting the circuit if it's bad. But also try turning up the volume knob on your guitar to 10 and make sure the DS-1's level knob is at least a quarter of the way up. You'll have to have at least 1.75Volts going through the LED for it to light. Lighting isn't important in the pedal; clipping the sound of your guitar is. Even if there is so little voltage going through the pedal that the LEDs don't light, those diodes are still clipping the modulating wave. It takes more electricity to light the LEDs than it does the change the sound of your guitar. Function's more important than form.
Hello Mr. Scmidtn. Thanks for your Guide Actually, I have a problem in my OD-3. I changed the stock LED to the Ultra Bight LED. When I plug in the Adapter, the Blue Light color shifted to Green. I learned that this thing happen because the Resistor that connect the LED. I've searched on the web about service notes & other PCB layout of OD-3. I got a layout drawn by a fellow. But, I can't locate that resistor because the OD-3 layout that I downloaded is not clear as the service notes. How I locate that resistor by seeing out the PCB ?? Thx
Schmidtn (author)  djajasoekarta7 years ago
I did this mod to a Boss DS-1 pedal. I've never seen the inside of a Boss OD-3 pedal, but if you know where the LED belongs on the board then there should be a resistor directly in front of it in the circuit. So trace the leads of the LED to the components on either side of the LED and the anode (positive) side should be your limiting resistor. For most LEDs you're safe using a 1,000 ohm resistor (serious overkill), but the math for figuring it out is; ({power supply in volts} - {forward draw of the resistor}) / {LED current in amps} = resistor value in ohms.
So we know you're power supply is 9 volts. Forward draw is somewhere between 1.5Vf and 4.0Vf. LED current is normally 20mA (0.020 Amps) or 10mA (0.010 Amps) but sometimes are different oddball numbers. You should be able to find both of those numbers on the packaging your LED came in. After you do that math, you'll have the absolute minimum ohms for your resistor, but it's best to bump that number up a little. The LED will glow a teeny bit duller, but will use less electricity and burn out much slower.
Ex: if your LED had a forward voltage of 3.2volts and a current of 25mA;
( 9 - 3.2 ) / 0.025 = 232 Ohms... you can buy a 232 Ohm resistor, but I'd bump that up a little bit to a 240 or a 249 Ohm resistor.
One more thing; the new resistor should fix your dull glowing LED problem, but if you damaged the LED, a new resistor wont fix that. You might need to put in a new LED as well.
Ok, I mind it. Thx before. Oh y, I got a same problem to my Keeley-Like Mod DS-1 (Like in this site) that I done by Myself. I change 3.9 K LED resistor (R35) with 2.4 K resistor. The Ultra Bright LED shifted to green & it's dimmer (Not so Dim) than the LED which connected to 3 Volt source. If my LED connected to 3V source it light so clear & the color is perfect blue. It's lighter than the LED which I connected to my DS-1. They are SAME LED My question, Is the resistance of my resistor (R35 DS-1) should be increased or decreased ?? If I use lighter LED, what should I do with LED resistor ?? According to your post before why with math we got a resistance value in order of 100 ??