Boss - DS-1 Distortion mods (what works, what doesn't?)

A forum devoted to mod, tips and suggestions for upgrading and rehousing your VERY CHEAP commercial stompbox to near boutique excellence.
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5thumbs
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Post by 5thumbs »

I wrote that original document as therapy... to the church-youth-kids I did sound for. I was inspired by R.G. Keen.

I've been dark for nearly a decade, mostly due to sickness. I just today showed it to a fellow guitar-playing friend. But I am enthused in the fact that these mods still stand up well. :-)

I still play old guitar-rock through these pedals... I keep an example of each on my pedal-board. I've had many tube-amps through the years, but I've downsized to a Vox tonelab se (the old one) and a few tube amps.

The DS-1 isn't that complicated, much like the tube-screamer. Just read, mod, and listen and you can do similar. :-)
Modding a DS-1? Please read 'Build Your Own DS-1 Distortion'.

"Other than a good first-in-line buffer/booster, using other FX to improve bad clean tone is like gift-wrapping garbage."

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Vinz35
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Post by Vinz35 »

Hi everyone,

I wanted to buy a Boss DS1 as a first "modding project" so I bought a used DS1, a MIT version around 25€.
I never played a DS1 before and I thought the stock version sounded quite nice. Still I bought the components to do the Keeley version.
I started to remove C2, C3, C1, C8, C12 and C14... then I realised my circuit board was a 1991 MIT with the TA7136 op amp, very similar to the MIJ version.

(like this one on the right Image, source: stompboxzone)

So I stopped everything.

What would you do ? Would you put the old components back in place ?
Can I still replace C1, C3, C5, C12 with 0.1Uf Caps (I bought MKTs) and is there any interest to do so if I don't do the rest of the mod ? and C2 and C8 with 1uF caps ? (even if C8 is already a 1uF cap in the MIJ version as written in Brett's document, which is excellent by the way).

I'm a bit lost.

Thanks in advance.

Vincent

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Renegadrian
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Post by Renegadrian »

Mod the sh*t out of it. Dont forget to mod the tone section.

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Vinz35
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Post by Vinz35 »

Do you know if there is any modification to do to the keeley mod to adapt it to the pre 1994 version ?

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Renegadrian
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Post by Renegadrian »

Vinz35 wrote:Do you know if there is any modification to do to the keeley mod to adapt it to the pre 1994 version ?
No afair.

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javimart1212
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Post by javimart1212 »

Bought a boss ds 1 to for a modding project and I didn't realize how good it could sound. I rehoused it in a 125b enclosure, made it true bypass, and did the jcm mod with extra gain. Now this 30$ pedal is a freakin beast! I totally recommend this to anyone looking for a cheap dirt project.
20190721_210941.jpg

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nooneknows
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Post by nooneknows »

Hi,
this is a zombie thread that sometimes got out, but I'd like to share my DS1 mods too.

In the VH fever around I was trying different boxes to obtain a decent VH 1 sound with my Fender Princeton and my strat (ok, impossible, but we are here for fun), I tried different things (plexi drive, ocd, ecc. I have around, combined with some boost) then I realize I had an unused DS-1 in the drawer, victim of some mod, I wonder if I'd be able to have something with just one box.

Well, after a thousand of mods I think I've come with something in the ballbark with these ones, combining AMZ fat mod, simplified keeley ultra mod and toying around with tone stack calculator trying flatting the mids. This is the list, with component, original value, mod value:


R9 , 22, 270 (quasi AMZ FAT mod)
C5, 68nF, 220nF (quasi Keeley Ultra)
C7, 10pF, 220pF (quasi Keeley Ultra)
R13, 4K7, 1K2 (to raise the gain)
C8, 470nF, 2.2uF (to keep the same high pass freq)
R14, 2K2, 1K5 (Keeley Ultra)
D4, 1n4148, LED (Keeley Ultra)
D5, 1n4148, LED (Keeley Ultra)
C, -, 56pF across the diodes (taming spikes)
R16, 6K8, 1K (flat mids)
R17, 6k8, 10K (flat mids)
R15, 2K2, short (flat mids)

I'm not a fan of caps substitution unless strictly necessary, I can't hear significative audible differences and the filters cutoff are in most cases way beyond lowest guitar freq, also I feel the hype around good quality caps is a bit overrated in a high gain distortion pedal, Boss caps are usually more than enough to my ears. The only exception is C5, I don't know exactly why but I hear some difference between original and modified value.

have fun

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Post by theblackman »

5thumbs wrote: 13 Jun 2018, 04:48
I've been dark for nearly a decade, mostly due to sickness. I just today showed it to a fellow guitar-playing friend. But I am enthused in the fact that these mods still stand up well. :-)
i just modded my old ds-1 with your MIJ mod. it's really great, I'm very surprised how much better it is than stock MIT. So if you're still around, THANKS FOR SHARING!!

I think i might try the huevo grandes in my super feedbacker DF-2

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jeepe
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not totally green, but that's all :)
my "level" is about building a big muff... medium complexity :)

I'll never build a DS-2, for example :)

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even though I'm a layman to electronics
I'll never build anything without seeing the actual schematics too...

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my all time favorite: Fuzz FAce
it is an always ongoing project..
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I want to end up strumming some strings at the end of the day, whatever the sound

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I'm so sad that this beautiful culture (and freedom movement) is totally ephemeral
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Post by jeepe »

well, Guys,

thanks a lot...
this conversation is extremely helpful...

I've made one and sounds decent...

and to the next one I'm making I want to add some mods which make improvement in a sane way...

so far "the MIJ mod" sounded good and modest enough to me...
as described in the great make yourself a DS-1 doc... (similar title, you know which)

the MIJ mod claims that an electrolyte 0,47uF would be great...
adding that changing it to a film cap would be off concept :) "hybrid" as he called it...
whereas the keeley mods start with electrolyte replacements, to film caps

in this how to make your own ds-1 they also state that the early DS-1s had ceramic caps... :)

so, your JFET change, Baja, sounds extremely sane and simple...
and it is great to hear that cheaper ones are absolutely okay, too :)

PS:
the problem with this thread is its age...
all images and links have become broken...

still, this is a great resource :)
pedal building, tracing and sharing is such a beautiful freedom movement... If only it could be viewed as a future heritage, but it really is ephemeral, as it seems

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modman
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Post by modman »

jeepe wrote: 22 Oct 2021, 22:40 PS:
the problem with this thread is its age...
all images and links have become broken...

still, this is a great resource :)
You are absolutely right, I was able to retrieve info on the Keeley mod and from Erik Hansen's blog here.
Still I would always start here with 5thumb's incredible summary.

I would just like to take this opportunity to encourage people to use the attachment function. Be sensible, but please don't hold back.
And please, anybody that got anything from this thread and is working on DS-1, chime in, share your experiences, revelation and disappointments with this pedal.
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

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teddeeh
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Post by teddeeh »

So i modded to the keeley mod in a doc i found on diysb. I was never happy and it sat for ages. So im currently undoing that, redoing a clipping mod and going to work from stock again. Somethingni think i do want to keep before any mods is the 100nf input cap. More butter more tasty.

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Post by kungpow »

Just did amz fat mod, Wampler jcm 800 mod, and also changed c12 for more mids, all together. Sounds pretty good. Aggressive marshally sound. Tone knob doesn't do much, seems to affect a tiny range of high frequency. I use it assault the front end of my Orange or15. Stock I found it unusable.
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Lukasen
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Post by Lukasen »

The Boss DS-1 was one of the first effects I modified. I gradually returned to it as I gained knowledge (to put it mildly).
I was hooked on the AMZ fat mod (R6 = 100k -> 150k, R9 = 22R -> 1k). With it, the sound was much warmer and more usable. But my intention was to use the effect with the bass guitar, so I changed C3 = 47 nF -> 150 nF after a lot of editing.
Furthermore, I did not enjoy the BMP type of tone control. So I simply shorted C11 and that makes it sound similar to when you use the tone control on the instrument.
Another modification was the replacement of the first buffer. I really don't like the sound that comes through the DS-1 off and it would be a reason for rehousing (which I didn't want, I'm lazy and prefer to think). At the same time, even the first buffer brings all frequencies into distortion, so you can change a lot! So I replaced it with BS-170. Just turn the pin source to the other side of the case. And then solder a Zener diode 9V1 between gate and source for protection and R2 = 470k -> 1M for higher Zin. Suddenly, there were more highs in the original signal and in the distortion, metallic longer and more permanent sustain.
The last modification was a complete surprise even for me. You know what the Boss DS-1 is missing (and unfortunately, other distortion pedals too)? This is a very fundamental way to ensure the operation of the operational amplifier, especially at high gain, to minimize noise. Yes, it is a ceramic bypass capacitor between the power pin and the ground pin. There is none near the opamp. So you only need to solder 100 nF there and this will significantly reduce the noise at higher gains.
Look carefully in your pedals and fill in where they are missing, you will be surprised yourself... :-).

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