Introduction: Modify Your Boss DS-1

Picture of 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

Step 1: Supplies

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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.


LucasA106 (author)2017-01-13

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

Strix28 (author)2016-07-16

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

ScottF80 (author)2016-05-10

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!

Logan302 (author)2016-04-28

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

ohall1 made it! (author)2016-04-05

I did this mod over two days and about 6 hours total. Have to say I underestimated the time it would take to remove the components. If I did it again I would make sure to have a good solder pump and smaller tip. Also make sure whatever capacitors you purchase are on the small side. The ones I bought from mouser were double the size of the stock caps and I had to bend them around to fit everything back inside.

These instructions were fantastic. I had no trouble at all following the steps and it worked the first time I plugged it in. It's hard to believe the difference this mod makes to the sound of the pedal. The youtube comparisons don't do it justice. Blown away... can't wait to show this off!

Hellspawn666 made it! (author)2015-12-07

I did this Mod this weekend and the difference is incredible ! Great instructable, had no trouble at all. Thanks!

lectricity (author)2015-10-18

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.

GooveTankPro (author)2015-08-05

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?

SoldeRon made it! (author)2015-04-05

This is a great instructable. I was a little wary since there are a few posts about problems that other people have had, so I tried to be extra careful. However I did manage to overheat one lead on the spdt switch. I bought a new one at Vetco. I later saw that my local Radio Shack has them in stock. I also reversed the input & output jacks when putting it back together. I would advise anyone doing this mod to take note of the wire colors of the jacks and pots. Pictures are nice, but taking good notes is better.

The tone is incredible compared to what it used to be. It's not difficult and it's well worth the effort.

Here's my daughter playing a mini Strat through the modded DS-1 (input/output jacks reversed) through a Marshall 50 watt combo.

Mutatedmexican (author)2015-04-01

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

Andy.Racks (author)2015-03-31

Brilliant. Love it! Thank you.

Surgegainsboard (author)2015-01-02

Isn't Tone subjective? ... didn't Kurt and Joe and John use non-modified DS-1's?

pbetts2 (author)Surgegainsboard2015-01-08

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.

dgbwashington (author)2014-12-29

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.

ethancool12345 (author)2014-12-08

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

BittenHand19 (author)2014-09-07

benJ80 (author)2014-06-22

Hi James,

What brand do you use for resistors ? (The links does'nt works)



AaronS1 (author)benJ802014-08-02

The link should work now. I had to update my quantity available (I was sold out).

jbravo6 (author)2014-05-29

Hi guys, with the actual stock boss DS-1, is possible to do these MODs???



Mxzx (author)2014-03-25

Well I tried taking it apart, running with just the Seeing Eye Mod (no Ultra) and it still has the hum and flashing LED's with the distortion knob up. I checked all the solder joints and nothing is bridged. I took wires out of D4 and D5, without D4 and D5 diodes (which were clipped before I got the pedal), the pedal sounds normal? Any ideas would be great!


Mxzx (author)2014-03-18

Thanks for the reply, I'll def give that a shot and report back.
I did the ultra mod too, and put the other LED in the "Dist" letters. They both exhibit the flashing when the ultra is engaged and dist knob past 3 o'clock.

Mxzx (author)2014-03-18

Hello, just did the mod and it worked the first time!! I have two issues though, when the distortion is turned past 3 o'clock, the seeing eye led starts flashing like it is picking up the 60 cycle hum or something, pedal makes noise at that point too. It is also very bassy, any way to cut that down some?

James Haskin (author)Mxzx2014-03-18

A lot of people, myself included, have had trouble when reassembling the pedal. Sometimes a wire gets pinched or a contact bridged. My first step in trouble shooting would be to see if the mod works properly outside of the enclosure. Best of luck.

AlpK made it! (author)2014-02-23

Thank you very much! That was my first DIY projet and "It's alive!"

James Haskin (author)AlpK2014-02-23

Awesome! I wish you good luck on your journey as you explore the world of DIY.

ectobass (author)2014-02-04

A couple of comments. In the removal instructions it isn't clear that you need to remove D4 for the ultra mod. Also, you could use a diamond file to widen the holes for D5 so you can fit the 24 AWG wire and the D5 in the same holes. One caution on reassembly. It looks like the tone pot lead can hit the case of the switch if you aren't careful. Similar situation for the other pots hitting the case (ground) of another pot if they are not lined up. Great mod! Thank you so much for taking the time to put this together.

DenVeR777 (author)2010-06-09

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.

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.



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!


JeppyMod (author)JeppyMod2012-10-30

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 ...


BrMr (author)JeppyMod2013-11-26

Any update? I have exact same problem. Please help

drummerboy2004 (author)2013-08-25

I don't have that pedal. Cause I have a pedal that does 50 different effects.

robertjune1988 (author)2013-07-13

Hello! I'm trying to find all the components to make the modification, but in my country it's very difficult to find the monolythic capacitor, or the mica capacitor. Is it possible to replace it with a standard ceramic capacitor. Another question: the 47 pF is a standard ceramic capacitor? Bye!

zyroth (author)2013-01-12

I did this mod last week and ended up with the problem where the level button would actually lower the output when passed 2 o'clock mentionned by DenVeR777, Andrew Gartshore, JeppyMod

I double checked my components and everything was correctly placed with the specified values.
When I opened by DS-1 to check the components I noticed that the UltraMod switch casing was touching one of the solder points on the Tone knob PCB. The casing of the pedal is a ground and since the switch is attached to the casing I suspect it was inadvertently grounding that part of the circuit.

I detached the switch from the pedal casing and tested it.  Guess what?  It works fine.
I guess I drilled the hole for the switch a tad to close to the Tone knob

demenciaguitar (author)2012-11-09

The mod works pretty well thanks! However the sound is a bit thin for me, and the distortion just to rich in the high end. To be honest I prefer the mod by Pedaldoc which I installed last year in my other Ds1 and gives a much darker sound.

Dominchio (author)2012-11-04

Hi James, I might be a bit late...
thanks for your brilliant tutorial although I am a bit confused (I'm also new to soldering... :-)
I'm going to do just a Ultra Mod, but am confused as for what to do with D5 and D4.
Do I need to de-solder D5 diode and leave it empty since I am not going to use the switch?
Additionally what do I do with D4?

Thank you any help would be appreciated. D.

davidwaligora (author)2010-03-01

 so i tried this mod.  minor issue....  the seeing eye led doesn't light up, and i get no sound at all.  when i turn it on it picks up a radio station.  I had an issue getting r39 out and it may be i ruined the connection because it just wouldn't solder right.  this is my first time ever doing something like this so i'm a little lost.  any ideas would be appreciated.

mrmerino (author)davidwaligora2011-11-23

It picks up a radio station? Whoa.

Mythbuster009 (author)mrmerino2012-06-16

I'm with mrmerino... I don't think picking up a radio station with your pedal is covered by the warranty (just joking). You're probably going to have to start over and try having a cleaner soldering/de-soldering technique. You may have used parts that were faulty, of the wrong value, or just accidentally put in backwards (guilty on multiple counts). Best of luck!

pastorronnie (author)2011-12-06

Finished this Mod today, sounds killer. I couldn't quite find the exact parts listed here, but honestly ordered as close as i could from Small Bear Elec. and they all worked great.

Definitely worth taking the time to do this mod. would never use this pedal before now it has a home on my pedalboard. Especially when you drive it with a OCD you get some awesome lead sound to push you out in front of a rocking band.

blacknoise (author)2011-10-12

I've done the mod, and it sounds awesome!

The only problem I'm having is the bypass. It seems to work (the blue led goes out) but I still hear the distorted sound slightly (like some of it is leaking into the clean signal) and the signal is very quiet and also changes when I move the volume/gain control. It felt like something snapped when I was tightening the nut on the volume pot, but I could't see any broken parts or solder joints...

Any ideas?

Instructionsplease (author)2011-09-05

First off, I have to say good job on the instructions.

I'm really new to this kind of stuff so please forgive me if I get a bit confusing. I'll try to explain to the best of my ability.

I had first bought different parts and put everything together and it had distortion and was working, but it didn't have the sound I was looking for. Also, the distortion knob wasn't working. It was more of a fuzz effect. Another problem is that the 0.047uF capacitor in C11 was too big and was sticking out of my pedal. So I went back and bought the ones that were on here that you provided a link for and got most of them, except one which would be the capacitor on R39. I'm sure it's the same one it can hold. I was excited to hear how it would sound and when I tried it out, the red light was on and flickering pretty fast. The more I turned the distortion knob, slower it would blink. It also had a constant buzz and would get higher tone whenever I lowered it and speed up the noise. It would do the opposite when I turned the dist. knob the other way (low and slow vibration sound). The red light also would get brighter as I turned the switch by the tone. I did everything how you said it and am a bit confused. If you could possibly help me out, I'd appreciate it very much. Let me know if you need further explanation. Thanks

thrilli (author)2010-08-20

Umm. I have a kinda stupid question here :/ ... Should the original diodes from D4 and D5 be completely replaced by the LED-Diodes used to both mods (not be used in conjuction with either of the LED-diodes). So I just connect the wires for the switch and for the ASE-LED to the places they are supposed to go (ASE LED Wires to D5 ans the Ultra switch wires to D4) and the original diodes become obsolete? Everythings seems to work flawlessly (Except the Ulrta switch which was a REALLY crappy quality and has connection faults with it). It is just that the overall gain went down a lot and the switching doesn't seem to do much (just a slight change in volume and definition). Did anyone else experienced similar? I know i can boost the gain by changing several different resistor values and such but I'm just wondering if this was to be expected when doing this mod. Oh and BTW i did differ from these instructions by also changing by C10 -> 0,022uF to rid the harsh top end, didn't help at all :( sry for the long post

digitalmike101 (author)thrilli2011-08-16

Hello Thrilli,

I did this full mod and it worked out great and sounds awesome. This is for you or anyone out there:

It sounds great but still a little harsh with a Strat. I heard you can change the C10 cap. Have you tried using another cap to warm up the sound beside the .022uF cap?


rdlpz (author)2011-07-31

I studied your procedures and thought them too difficult to attempt in their entirety. So I changed just the D4 and D5 by substituting the 3mm red LEDs and found that just that simple change improved the sound. The sound is now less harsh which was my main complaint with the original pedal. I was able to do this without removing everything from the pedal case. The C2 and C3 changes can also be made simply without removing the pcb completely from the case. Will the .1 and 1.0 uf stack metal film cap changes to C2 and C3 also improve the sound without doing anything else?

matteo320 (author)2011-07-12

hey thanks for the guide! it has completely transformed this pedal! great instructions made the mod a breeze! thanks

Like A Boss (author)2011-07-03

You can’t modify me.
Like a Boss!

jgcapdevielle (author)2011-06-14

Hi, first i want to thank you to teaching us these wonderful mod, i have a question for you i dont reuse de red led that is hidden in the box, i used a blue one, will these affect in anyway the tone ???'
thanks again

_olarlite (author)2011-06-06

Done. Thanks!

teslasteroid (author)2011-05-24

Thanks a lot..........It sounds great!!!!

About This Instructable




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