Modify Your Boss DS-1




Every guitarist at some point has at least tried Boss's DS-1 distortion pedal. Most People are immediately disappointed. This over hyped pedal sounds really thin with no punch. Sales people at guitar center will say something like its a "great beginner distortion pedal". Its been my experience that most of the people that work at guitar center are useless. So, always research and get information from multiple sources.

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

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Step 1: Supplies

Soldering Iron/Station *I LOVE my Weller WESD51 I got for Christmas but it is a bit overkill :]
Eye Protection
60/40 Rosin Flux Core Solder
Wire Stripper
Desoldering Equipment
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
Flush Cutters
Drill *Anyone want to give me one? :]
1/4" and 7/64" Drill Bits

Components- Kits available at!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

In order to modify this distortion pedal you need to gain access to the circuit board. When taking things apart there are some basic rules.
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.

*Disassembly complete

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

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.

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156 Discussions


Question 9 months ago

Do you know how to do these mods with the new (since 2016, I believe) circuit board? It's a LOT smaller than the old boards. I was wanting to do the D4 D5 mod, but, I'm not sure if it'll be the same since the board is different.


9 years ago on Step 8

Thanx James! This is very useful instruction. But I've got a problem: Dist knob at low values work perfectly, but when I rise dist value to 12h low level signal dissapear and it's treshold rise with dist level. Another thing is there about 3,5-7v dc on a input jack, its also depend from dist level. Can anyone tells what i do wrong? Sorry for my english.

5 replies
Andrew GartshoreDenVeR777

Reply 6 years ago on Step 8

Hi guys,

I know I'm little late, but I just did this mod and ran into the same problems. The distortion knobs works to about 1-2 oclock then starts to attenuate the signal. At max distortion it will only work if the guitar is played really hard. Soft notes don't go through at all. I returned the Diodes to the originals, leaving everything the same and it still acts the same. Any hints?

Any help would be very appreciative.


RafiS7Andrew Gartshore

Reply 1 year ago

Old thread but I've just did the mod. And encoutered the same issue - distortion above 2 o'clock makes the pedal work like sort of noise suspencer. So... when three or four people have exactly the same problem after following the instructions then there must be something wrong with the instruction I guess....
If anyone solved this problem - please drop me a line....


I Andrew, any feedback on your problem.
I stricktly follow the instructions and have the same strange behaviors with volume and distorsion knobs after modifications!



Reply 6 years ago on Introduction

Hi guys,

Any update on this knob compression problems ?
I really followed the instructions step by step.
I can't believe that only 3 of us have the same behaviour ...



2 years ago

Hi. What kind of capacitor can I put in place of "Stack metal film"? They are obsolete and hard to find.


3 years ago

I get no sound at all when I plug in the pedal even when its off. I followed every step and i think i did them all correctly. I wasn't able to find an AWG 24 hook up wire so i used an ordinary copper wire of similar gauge. Any ideas on how to solve this issue? Thanks


3 years ago

Great how to. A couple of things that made it easier for me. 1)solder the red LED directly to the pcb at D5. Solder the second LED directly to the switch (bend at right angle and solder it to the switch, insulate the leads.) Came out Great!


3 years ago

Thanks for sharing. Great ible for Boss DS-1 users


3 years ago

so finally completed this after a while. the change is quite big, for the better! but it seems quite noisy on my headphones - are my caps bad? i'll check it later on some proper gear.

the instructable is very thorough, but a proper circuit diagram would benefit on the led mods page... Thank you for all.


4 years ago on Introduction

Currently all I am getting is a loud ground hum when the pedal is on or off. I found (somehow) that running a wire from the sleeve post of the output jack to the positive side of the main blue LED gets rid of the hum and allows audio to pass through while the pedal is turned on, but the ground hum is still there when I turn the pedal off. Clearly I did something wrong, any solutions or ideas?


4 years ago

Is this mod hard to do I've never done one and don't want to ruin my pedal


Reply 4 years ago

According to the internet, Kurt Cobain used the 1980s version, which had different components than the 90s pedal. I don't know how that compares to a 2015 pedal, however.


Hopefully some of you read this before you start to know what to
expect. I had it right the first time but wasted a whole day
troubleshooting something that wasn't broke.

Wow, what an experience this was. Took my time and was diligent the entire process. Before reassembling, I thought I would make sure the "seeing eye" LED worked. Nope!!! After hours and hours of troubleshooting and reassessing the assembly I decided to button it up and if it didn't work, I would add to my junk box... Low and behold, the seeing eye doesn't work until you actually put a signal through the device. I didn't try this before assembling it back as I assumed when "seeing eye" mode selected the LED would illuminate. It actually works on both mod's in the pedal for what it's worth. Not sure if that is by design though. I can switch between mod's with added sw mod and there is a difference between the two.

Was it worth it? Yes, I think so. I did the full meal deal mod and have a distortion pedal with some killer tone. You will have to play with it to dial it in but once you do it is a huge upgrade to the stock DS-1 for $20 more. Just be aware the "seeing eye" will only work with a signal.

despite the fact that I am only 12 I dont get the led connection you said that 2 led lights had to be connect d5 and d4 but there is also another light source in the numbers 18 and 16 so there are three led lights but than which are the led lights needed and which in is not or maybe the on that is not might interfere with the other connections so could you please tell what light and connection e.g. D5 to the tone hole otherwise tell me what O don't need