Need help modding my Boss DS1

[Deny]

I know this has been discussed ad nauseum, but I'd still really appreciate a little help deciding which components to change in mine. I did a LOT of reading about these mods and was at first thinking about going with the Keeley Ultra/Seeing Eye, but then I read a bit further from some guys who seem to really know what they're talking about (like Mr. 11 Gauge from right here at tdpri.com for instance) and now my head is spinning and hurting from analyzing all the possibilities.

First things first, here's what I expect from my DS1: I want it to have a nice tight fuzz with more midrange and less fizz, maybe a bit more articulate than the current stock DS1, and not a lot of bottom end. Not that it's a bad pedal as it is, I like having the option of a more "raw" flavor of distortion and *by no means* do I want to convert my DS1 into an overdrive - I already have a Boogie Triaxis for that, I just want it to sound a bit "sweeter" I guess. Ok, I'll admit I do like the tones Satch and Vai get from their DS1's and it wouldn't hurt adding those to my arsenal :)

And here's what I've got so far from everything I was able to absorb from the tons of reading I've done from numerous articles from the web:

First, I want to get my DS1 to sound like a japanese DS1, so for that purpose I'll change:

C7 from 100pF to 250pF (hard to find in my area, 270pF should probably work?)
C8 from .47uF to 1uF
C5 from .068uF to .47uF
D4 and D5: add 4 x 1n60 in series with each 1n914 (1n60 forward voltage = 100mV, 1n914 = 550mV, original japanese diodes = 950mV)

Then in order to reduce the high end fizz and adding a bit more midrange:

R9 (Q2 Bias) from 22 to 100 ohms
R17 from 6k8 to 8k2 (slightly more mids)

I'm also considering adding a switch that will allow for asymmetrical clipping, keeping the normal configuration (1 silicon + 4 germanium on each side) in position A and shorting two germanium diodes from one side while adding two germanium diodes to the other side in position B (750mV / 1150mV forward voltage).

Opinions, suggestions?

Cheers,
Deny

[Jubal81]

Here's a link to Brian Wampler's pedal mod books. He goes over the DS-1 quite extensively.

http://www.sendspace.com/file/mpcnvg

[Deny]

Originally Posted by Jubal81

Here's a link to Brian Wampler's pedal mod books. He goes over the DS-1 quite extensively.

http://www.sendspace.com/file/mpcnvg

Thanks for the link, it will help my continuing experiments with my little pedal. I've performed the mod I've mentioned in my first post and here are my impressions so far:

1. Harshness/fizz is indeed reduced, and the gain is a bit lower as well.

2. Boss uses high fusion point solder, and the copper leads dettach from the PCB pretty easily, wish I knew that beforehand. I've found out that mixing some lower fusion point solder where I want to desolder makes things a lot easier.

3. The bump in the mids from putting an 8k2 resistor in R17 was too subtle, I'd really like more mids, especially around 900Hz.

4. There's too much bottom end somewhere around 300Hz (wild guess), still have no idea how to chop that off.

5. D4 and D5 were replaced by 1N4148 + 1N60 + 1N60 in series (on each side). I thought the 1N60 germanium diode had around 100mV forward voltage, not so, it's around 260mV. The 1N4148 measures around 550mV as expected, so the above combination yields approximately 1.05V. Maybe it contributes with the overall smoothing of the tone, but the transition into a raunchier distortion is too abrupt for my taste. I am probably going to experiment with asymmetrical clipping and possibly lowering the forward voltage at least on one side. Does the original DS1 (japanese) present this behavior too? Would a capacitor in parallel with D4 and D5 help smoothing out the distortion threshold? Value suggestions?

[Deny]

Not a lot of people posting around these parts, still I'll report my progress so far as I'm thinking I'm pretty much finished.

Tonight I tried a few other modifications I picked up here and there:

C3 from .047uF to .033uF (less bass)
C12 from .1uF to .022uF (more mids)
D4: back to 1N4148
D5: mini red led

It sounded good, but then it hit me: this Robert Keeley guy probably spent countless hours changing component values until he found something that sounded *really* good, whereas I've spent just a few hours and would probably spend many more until I got the pedal to sound the way I like it.

So guess what? Despite some negative comments on his all-seeing-eye and ultra mods, I gave them a shot - even drilled my pedal and installed the LED and switch. And I must admit it sounds *really* good, probably as good as a fuzz pedal can possibly sound. So there it is, the end of my quest for modding the DS1 was a rather vanilla one so to speak as it's been around for a while, but it still kicks some serious butt!

Now on to my next mod, the TS9DX :)

[Jubal81]

Thanks for filling us in on your experiments. I've had a DS-1 in the closet for years and you've got me thinking of getting it out and doing some tinkering.

Also, this pedal forum used to be a lot more active. The mods got involved when discussions turned to dissecting and evaluating stuff from 'boutique' builders and that was that.

My two favorite pedal spots on the web are freestompboxes.com and Madbean's forum. Great communities.

[Deny]

Originally Posted by Jubal81

Thanks for filling us in on your experiments. I've had a DS-1 in the closet for years and you've got me thinking of getting it out and doing some tinkering.

Also, this pedal forum used to be a lot more active. The mods got involved when discussions turned to dissecting and evaluating stuff from 'boutique' builders and that was that.

My two favorite pedal spots on the web are freestompboxes.com and Madbean's forum. Great communities.

Glad you enjoyed riding along with my little pedal mod journey :)

After playing with the Keeley mod a little more I can honesly say it's an amazing mod if you're picky about tone subtleties and dynamics, this mod makes me want to play almost as much as the (now legendary, for me at least) lead 2 green mode of my triaxis (loaded with mullard cv4004s, no less). I already had all the tube tone bliss I could possibly want, and was looking for a different flavor to add to my arsenal and to me the DS1 with the Keeley mod was it. Regarding seeing eye/ultra switch positions, I like the seeing eye but I must admit I like the ultra better - YMMV of course. What makes it special IMHO is a sparkling clarity and definition that is all of its own, very reminescent of some Vai work actually but it's so sensitive to different guitars and pickups I'd bet that's why I don't get his exact tone.

[elmoscafeo]

I've read a lot of posts about DS-1 mods both here and other sites and have come to the conclusion that most people are trying to get to D4/D5 clipping at 1.05V.

I kept my DS-1 mod basic and simple. I removed D4 and D5 and replaced them with Infrared LEDs. IR LEDs clip at...1.05V. I left all of the other components stock. I really like my DS-1 now and it behaves very nicely throughout the entire Dist and Tone ranges.

[Deny]

Originally Posted by elmoscafeo

I've read a lot of posts about DS-1 mods both here and other sites and have come to the conclusion that most people are trying to get to D4/D5 clipping at 1.05V.

I kept my DS-1 mod basic and simple. I removed D4 and D5 and replaced them with Infrared LEDs. IR LEDs clip at...1.05V. I left all of the other components stock. I really like my DS-1 now and it behaves very nicely throughout the entire Dist and Tone ranges.

Interesting post and perfect timing as I've got a bit deeper into the DIY world and have been reading around that 1V seems to be the "magic number" as far as forward voltage for diodes. Thanks for the info, might try that next :)

[cousinpaul]

Around 1V seems to be the agreed upon number for modding a post-'94, MIT DS-1 to MIJ specs. There are also a few cap changes involved. You can download Brett Miller's "Build Your Own DS-1 Distortion" PDF for details, as well as some other cool mods.

[elmoscafeo]

Just a quick update. I decided to try out asymmetrical clipping on my DS-1. I re-installed D5 and left D4 as an IR LED. To my ears, it sounds better. Not a lot of difference, but something about the "body" of the tone (if that makes any sense) sounds better.

[cousinpaul]

Originally Posted by elmoscafeo

Just a quick update. I decided to try out asymmetrical clipping on my DS-1. I re-installed D5 and left D4 as an IR LED. To my ears, it sounds better. Not a lot of difference, but something about the "body" of the tone (if that makes any sense) sounds better.

I'm using a similar array in my latest DS-1. I think it spreads out the attack a bit when one conducts a little faster than the other.