The DS-1 is actually used by many artists including Joe Satriani, Kurt Cobain, John Petrucci, and Steve Vai to name a few, BUT most of the big artists don't use the stock one. Why? Cuz it sucks!
The good news is this pedal is simple enough to modify!! In this instructable I will show you step by step, with lots of pictures, how to perform Robert Keeley's DS-ULTRA Mod. Check out the PDF
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Supplies
Soldering Iron/Station *I LOVE my Weller WESD51 I got for Christmas but it is a bit overkill :]
60/40 Rosin Flux Core Solder
Third Hand *Something to hold the circuit board while you work; friend, vice, ect.
1/2" and 7/16" Wrench
24 AWG Hook-Up Wire
Drill *Anyone want to give me one? :]
1/4" and 7/64" Drill Bits
Components- Kits available at http://www.maxwellaudiodesigns.com/#!mod-kits/c1b2j
24 AWG Hook-Up Wire
1.0uF 50V Stack Metal Film Capacitor x 4
0.1uF 50V Stack Metal Film Capacitor x 5
0.047uF 50V Stack Metal Film Capacitor x 1
47.0pF Capacitor x 1
220pF 50V Monolythic Ceramic or 220pF 500V Silver Mica Capacitor X1 (I'd go with the ceramic one, its
2.4k 1/4W Resistor x 1
20.0k 1/4W Resistor x 1
1.5k 1/4W Resistor x 1
On/On SPDT Switch x 1 *Only if you intend on doing both mods. I got 50 on ebay for $15 w/shipping.
3mm Blue LED x 1 *Optional
3mm Red LED x 1 *To incorporate both modes you need a total of 2 red LEDs. I reuse the one I replace with the blue one.
Step 2: Disassembly
1. Don't force it- Be patient, take your time, and assess the situation.
2. Don't lose it- Keep track of everything you remove. This include screw, covers, removed capacitors, resistors, ect.
3. Don't forget it- Its always a good idea to document how the thing fits together; draw diagrams, record video, take pictures. Better safe than sorry.
Now you're ready to take apart your DS-1...
1. Remove the battery and/or unplug the pedal. Always remove the power source when working on anything electronic. You could accidentally fry parts or even yourself.
2. Turn your pedal over and remove the four screws that hold on the backplate.
3. Now use your 1/2 in. wrench to remove the 2 nuts holding the input and output jacks in place.
4. Pry off the tone knobs and us your 7/16 in. wrench to remove the 3 nuts holding the potentiometers in place.
5. Remove the screw holding the LED assembly located underneath the circuit board. To move it out of the way take you thumb nail and lift the bottom then gently pull the power power jack back and out of its slot. You should now see the screw. Remove it.
6. Now you need to desolder the purple and black leads for the power switch from the board. Before you even pick up the iron watch these two videos on how to solder and desolder properly. Even if you've been doing this for a while. These are some good videos.
7. Just gently push the jacks, pots, and the LED in and remove the circuit board. You will need to pull the battery clip though the switch hole.
Step 3: Modifacation- Blue LED
So far I have modified two of these pedals. Both times I have put an LED in the wrong way somewhere and caused myself a lot of unnecessary worry. "Did I break it?" "Should I give up and buy a new one?"
So, make sure you put everything in correctly and you wont have this problem.
1. Desolder the red LED.
*On mine the positive pole connected to the orange wire in slot 15
2. Remove the plastic riser from the red LED and slip it onto the blue one.
3. Solder the blue LED to the board.
Step 4: Remove Old Components
Don't throw anything away we WILL need some things later.
You need to desolder...
C1, C3, C5, C11, C12, C13 - These are silver polyester film capacitors.
C2, C8, C9, C14 - These are round electrolytic capacitors (the new ones will be non-polar).
R13, R14, R39- These are resistors.
C7- This is a ceramic disc capacitor.
D5 - This is diode.
Step 5: New Components Pt.1
This is the easiest part of this entire project. Its just pug n' chug. All of these components are non polar so it doesn't matter which way you put them in.
1. Place a 2.4k resistor in R13
2. Place a 20k resistor in R39
3. Place a 1.5k resistor in R14
4. Place 1.0uF capacitors in C2, C8,C14 *Leave C9 alone for now. It will make the next step easier.
5. Place 0.1uF capacitors in C1, C3, C5, C12, C13
6. Place a 0.047uF capacitor in C11
7. Place a 220pf capacitor in C7
Step 6: New Components Pt.2
This is where it gets a little complicated. I've made a model to help you wrap your head around the concept.
1. To perform the Seeing Eye mod, you have to connect a 3mm red LED to D5 as shown. We will later mount this in the 'o' of tone.
2. For the Ultra mod you switch in another LED in series with D4 as shown. This LED will be on the inside and wont be seen.
Follow the diagram.
This is where you will most likely make a mistake if you are not careful. DOUBLE CHECK EVERYTHING!! If you wire it all up and the LED appears dim and you just put a new battery in it, You most likely put an LED or the orange diode in the wrong way. Make sure to leave enough wire to mount the LED and switch.
For the Ultra Mod you need to desolder D4 and solder a jumper to the switch as shown. Don't forget the orientation of the Diode.
Once all of you wires leading out of A,B,C, and D on the diagram are are soldered to the board, solder 1.0 uF capacitor into C9.
Last thing is to solder the 47pf cap across the back of D5 and D4 as shown.
Step 7: Reassembly
First you need to drill a 3mm (3/32"-1/4") hole in the "o" on Tone. This is where you'll mount the D5 LED. Then drill a hole for your toggle switch. Mine was 15/64". Use hot glue to hold the LED in place, bolt the switch on and start to reassemble the pedal. Look back at the disassembly picture if your not sure how things go together.
Then feed the wires for the stomp switch through the pedal and resolder the purple wire to 17 and the black wire to 13.
Step 8: Last Thoughts
About five years ago Robert Keeley was kind enough to publish how to do this modification on his website http://www.robertkeeley.com/audio6l6/dstech.html.
This is a great mod that drastically improves the tone of this pedal.
Also Overdrive Spider has had his How To up for a while. Check out his DS-1 Circuit Bends I like letter D the best.