Introduction: Modify Your Boss DS-1
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
Tools-
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 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.
*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 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.
162 Comments
2 months ago
I am making my own mod, I am planning 3 way switch for R9 (22ohm/100ohm/1k) and for D4/D5 (2XIRF530+IRF) / 2XLED+LED/ No Diode). I Swapped C10 and C12 with 22nF and R17 with 10k for better Tone Stack. 47nF for C10 and C12 makes too less treble.
Question 1 year ago on Step 4
Hi,
I used a germanium diode and yellow led in D5; I notices that switch turn on/off both mods, is it normal or I made a mistake? Is switch supposed to turn on Ultra mod only? regards Alex
1 year ago
One thing I came across with capacitors is that I have trouble finding Stack Metal Film Capacitors. I went to a couple electronic stores including mouser and they weren't sure exactly what they were. Are there any other names for it technically or when picking them up would they be listed verbatim as "Stack Metal Film"? Eager to start soldering so any answers or link would mean a lot. Thanks.
Question 1 year ago on Step 4
On of the jacks needs to be soldered but I don't know what wires I think it's the black and purple but I don't know where to solder on the jack
Question 2 years ago on Step 8
Hi! thanks for the help! great instructions. So i did this to my DS-1 and it mostly works but sometimes the main LED blinks out (like totally off) and randomly the pedal will just give screeching feedback. any idea what that could be? it wasn't doing that before i put it back in the enclosure so maybe i squished something?
Question 3 years ago
Hey,
I did the mod, took my time and had fun. It turns on , but the Tone and Level don't work, neither does the All Seeing Eye, nor the Ultra Mode Switch. Think I put those two in backwards or should I look elsewhere?
Thank you.
Tomm
Answer 3 years ago
Polarity of the diodes is where I had trouble. I'd recommend checking there.
Question 3 years ago on Introduction
I have a DS-1 from 1989 - the circuit board isn't labeled with R, and C values. I was able to find it in one of your pictures, but C11 doesn't seem to be labeled in your diagrams. Also, the 47pF cap across D4 and D5 doesn't seem to be shown unless I'm misreading something.
4 years ago
I recently shut down maxwellaudiodesigns.com, but you can still purchase kits to do this mod at https://reverb.com/item/6513163-boss-ds-1-keeley-mod-2018.
Question 5 years 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.
13 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.
Reply 11 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.
Thanks!
Reply 5 years 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....
Reply 11 years ago on Introduction
Hi,
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!
Thanks!
Reply 11 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 ...
Thanks
Reply 10 years ago on Introduction
Any update? I have exact same problem. Please help
6 years ago
Hi. What kind of capacitor can I put in place of "Stack metal film"? They are obsolete and hard to find.
7 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
7 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!
7 years ago
Thanks for sharing. Great ible for Boss DS-1 users