I want to build a DS-1!

[Elijah-Baley]

I never had a Boss DS-1 and I always built distortion pedals I liked more. But want to try the DS-1 and get fun with all the mods.
There are so much schematics and versions that I need to choice the right for me.
I found different versions adapted in different way, with some different values especially and different IC.
Old DS-1 used a single op-amp (TA7136P). Later the IC was replaced by a dual op-amp, but with some changes in the gain stages. Anyway, the two version sound very similar.

I want to build on veroboard the version with buffers and the dual op-amp without the switching system.
Tagboard has a bufferless (but even without the first stage) version with a rare M5223P and a complete version where suggest JRC4558, TL072 or similar.
Sabrotone has a bufferless version with Keeley switches and values change. There's a NJM3404AL on it (I think it should be 3404AD, because the format).
Dirtbox Layout has a single op-amp version, (LM741, TL061...).
The Aion version (Comet) can be built with the original single op-amp or with a JRC4558.
Tonepad schematic has something new. Original single op-amp and dual op-amp like a TL072, but for the dual op-amp version some value in the first stage change. ()

Meanwhile, I modified the layout of Dirtbox with a single op-amp swapping it to adjust it for a dual. But maybe I could use directly the verified tagboard layout. Do you think a JRC3404AD I could buy worth? it's more expansive than other dual op-amp.

What do you suggest about all this?

Thanks!

[Steben]

To be honest a second hand DS-1 is impossible to beat DIY ... the typical stompbox quality is the best part of so many BOSS pedals....
It is one of those pedals I modded to hell and back so many times ....
Just as the best Tube Screamer is modding a cheap SD-1 .....

[blackieNYC]

Someone gave me a newish DS1.  Horrible sounding pedal! And I'm a Boss fan. Interested to hear what mods you like. 

[ElectricDruid]

Someone gave me a newish DS1.  Horrible sounding pedal! And I'm a Boss fan. Interested to hear what mods you like.

There's dozens of Youtube videos that want to tell you how the pedal's great but you're using it wrong?!? And then there's probably dozens more telling you how *this* mod is the one that turns it into the killer tone pedal you always dreamt of!

I studied it a bit recently, as it happens. It's an odd design, and it got odder after the single-to-dual amp change, since one of the amps basically does nothing. It's there just to make the replacement easy. A lot of the buffering is just because of Boss's FET switching, and without that, there's really no need for it. From a noise point of view, probably better off without it. The crucial parts are the pre-op-amp boost stage, which tweaks the tone and provides the first clipping, since it is likely to hit the rails (+35dB max boost). Then comes the op-amp gain stage (clips again, now up to 60dB gain) and then the diodes (clips again, chops the level) and the tone control and volume. You could go directly out from there. The last bit is just another FET switch and another buffer.

[m4268588]

Input buffer is required. Don't leave it out.

[Elijah-Baley]

To be honest a second hand DS-1 is impossible to beat DIY ... the typical stompbox quality is the best part of so many BOSS pedals....
It is one of those pedals I modded to hell and back so many times ....
Just as the best Tube Screamer is modding a cheap SD-1 .....

You're right. But As you can understand I want to build, not to buy pedals. It's just for fun, to build it starting from zero, include how many pots and switches I wanted, if I wanted, etc.

Someone gave me a newish DS1.  Horrible sounding pedal! And I'm a Boss fan. Interested to hear what mods you like. 

In the DIY pedal forums you can find any kind of mod you want. Mods to reduce the scoop mid, clipping texture, gain amount, volume loss, op-amp, boost, true bypass, fuzziness, low end, fizziness... Wampler mods, JHS mod, Keeley mod, customized mod, fuzz/synth/oscillation mod...
The pedal is what it is, but I like to try all the possible mod when I try a new circuit.

I studied it a bit recently, as it happens. It's an odd design, and it got odder after the single-to-dual amp change, since one of the amps basically does nothing. It's there just to make the replacement easy. A lot of the buffering is just because of Boss's FET switching, and without that, there's really no need for it. From a noise point of view, probably better off without it. The crucial parts are the pre-op-amp boost stage, which tweaks the tone and provides the first clipping, since it is likely to hit the rails (+35dB max boost). Then comes the op-amp gain stage (clips again, now up to 60dB gain) and then the diodes (clips again, chops the level) and the tone control and volume. You could go directly out from there. The last bit is just another FET switch and another buffer.

Input buffer is required. Don't leave it out.

Indeed, I can't see what the buffer op-amp stage does, too. But it always be ok, afterall.

Maybe I could build this:
https://dirtboxlayouts.blogspot.com/2019/06/boss-ds-1-distortion-pre-1994.html
What is a good quality single op-amp? Burr Brown? I have a lot of dual op-amp alternative, but not much single op-amp.

Or this:
https://tagboardeffects.blogspot.com/2014/10/boss-ds-1-distortion.html
I have a lot of dual op-amp alternative.
https://reverb.com/news/swapping-boss-ds-1-op-amps-hear-20-variations-in-action
It seems that the op-amp make a lot of difference!

Well, thinking to the DS-1 buffers, I thought the output buffer was more important than the input buffer, for the impedance. (For Example the las version of the OCD has added an output stage to improve the signal in chain with other pedal after it.) Instead, I thought if I don't include the input buffer there's anyway a booster stage, that works kind of like that.

I wanted to built the whole schematic of the DS-1, excluding the fet switching.

We need some schematics:

[ElectricDruid]

Input buffer is required. Don't leave it out.

The Q1 buffer has a higher impedance than the Q2 gain stage, so yeah, there's that.

[andy-h-h]

Or you could get really weird and try it with a discrete op amp.   

https://vero-p2p.blogspot.com/2021/10/boss-modded-ds-1-diode-compression-opamp.html

[antonis]

Input buffer is required. Don't leave it out.

The Q1 buffer has a higher impedance than the Q2 gain stage, so yeah, there's that.

By making R10 470k and IC1A with gain of that of Q2 stage, he can delete both Q1 & Q2 stages..
(with extra bonus IN-OUT been in phase..)

[Steben]

Input buffer is required. Don't leave it out.

The Q1 buffer has a higher impedance than the Q2 gain stage, so yeah, there's that.

By making R10 470k and IC1A with gain of that of Q2 stage, he can delete both Q1 & Q2 stages..
(with extra bonus IN-OUT been in phase..)

Channel 1 of ds2 is pretty much that. I did not notice that much difference in tone indeed.....

[ElectricDruid]

By making R10 470k and IC1A with gain of that of Q2 stage, he can delete both Q1 & Q2 stages..
(with extra bonus IN-OUT been in phase..)

I had this thought too. There's some tone shaping around Q2 which is important, but it's possible to copy that too. I had a go in LTspice and got the frequency responses identical through the different stages:


It seemed to me there was quite a lot of simplifications could be done to the circuit, especially given that there's a "spare" op-amp in the original circuit waiting to be used.
The potential problem with this (if there is one - I haven't tried it to listen to, and I don't have a DS-1 to compare it to either) is that the Q2 will clip pretty heavily, so if the op-amp distortion has a different character, you'll end up changing the tone of the pedal. It might be *better*, who knows?!? But it won't be a DS-1 exactly any more...

<edit>Steben is fast! Ok, so it might work quite nicely, if the DS-2 doesn't sound so different.

[Elijah-Baley]

Thanks to everybody for your answers. I didn't know if I had to start this thread because the topic could be a bit "old".

Or you could get really weird and try it with a discrete op amp.   
https://vero-p2p.blogspot.com/2021/10/boss-modded-ds-1-diode-compression-opamp.html

Input buffer is required. Don't leave it out.

The Q1 buffer has a higher impedance than the Q2 gain stage, so yeah, there's that.

By making R10 470k and IC1A with gain of that of Q2 stage, he can delete both Q1 & Q2 stages..
(with extra bonus IN-OUT been in phase..)

Thanks, but I prefer to build something more close to the original pedal.

DS-1 and DS-2 are made in very different way, though. I  drawn a veroboard layout of the DS-2, but I never wanted to verify it. Maybe I'll post in the forum.

Right now the tagboard layout is winning. I'm woriking on the design to make it more "moddable".
Then, my impression si that nice op-amp for clean boost or buffer are not so good in distortion pedal. I'm not sure if I had to buy more expansive IC (not absurdly expensive) and to find I like TL072 or JRC4558.

[Steben]

Thanks to everybody for your answers. I didn't know if I had to start this thread because the topic could be a bit "old".

Or you could get really weird and try it with a discrete op amp.   
https://vero-p2p.blogspot.com/2021/10/boss-modded-ds-1-diode-compression-opamp.html

Input buffer is required. Don't leave it out.

The Q1 buffer has a higher impedance than the Q2 gain stage, so yeah, there's that.

By making R10 470k and IC1A with gain of that of Q2 stage, he can delete both Q1 & Q2 stages..
(with extra bonus IN-OUT been in phase..)

Thanks, but I prefer to build something more close to the original pedal.

DS-1 and DS-2 are made in very different way, though. I  drawn a veroboard layout of the DS-2, but I never wanted to verify it. Maybe I'll post in the forum.

Right now the tagboard layout is winning. I'm woriking on the design to make it more "moddable".
Then, my impression si that nice op-amp for clean boost or buffer are not so good in distortion pedal. I'm not sure if I had to buy more expansive IC (not absurdly expensive) and to find I like TL072 or JRC4558.

DS-2 does have a BJT stage in front as well.... Frankly the slight differences between DS1 and DS2 in distortion 1 mode are slightly in favour of the DS2.
That's taste .

[ElectricDruid]

Thanks, but I prefer to build something more close to the original pedal.

Fair enough. You know what us lot are like - give us a schematic and we can't leave well alone

[Steben]

Thanks, but I prefer to build something more close to the original pedal.

Fair enough. You know what us lot are like - give us a schematic and we can't leave well alone

My favourite mod is lowering gain (def Q2) followed by having higher clipping treshold (LED's) - perhaps tinkering with complex clipping and also more mids in the tone control.
So yeah .... pretty much what you say.

[Elijah-Baley]

Fair enough. You know what us lot are like - give us a schematic and we can't leave well alone

I'll post soon a schematic with my comments about the mod of a lot of parts.

Thanks, but I prefer to build something more close to the original pedal.

Fair enough. You know what us lot are like - give us a schematic and we can't leave well alone

My favourite mod is lowering gain (def Q2) followed by having higher clipping treshold (LED's) - perhaps tinkering with complex clipping and also more mids in the tone control.
So yeah .... pretty much what you say.

To make sounds "better" this pedal the mods you mentioned are a must: less boost, more dynamic clipping (and more volume), more low end, more mids and smoother high.
I'm not sure if I'll build a simple modified DS-1, but I like to hear the difference between the original one and the mods. Maybe some mod will be fixed, but for other mods I'll use switches.

One thing is sure. Dual op-amp version.
Not because that, but I was thinking about the op-amp buffer stage. What if I turn it into a boost stage? Is it too much for this circuit?

[antonis]

I'm not sure if I'll build a simple modified DS-1, but I like to hear the difference between the original one and the mods.

https://www.premierguitar.com/diy/pedal-projects/boss-ds-1-mods
https://www.csguitars.co.uk/ds1-mod
https://www.instructables.com/Modify-Your-Boss-DS-1/
and of course: https://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf

[ElectricDruid]

One thing is sure. Dual op-amp version.
Not because that, but I was thinking about the op-amp buffer stage. What if I turn it into a boost stage? Is it too much for this circuit?

I'd say, yes, it probably *is* too much for this circuit. That Q2 gain stage has +35dB, so there's already a lot of boosting going on ahead of the op-amp.
But yeah, why not? Turn the DS-1 into a high gain monster pedal! Alternatively, if you modded the Q2 stage for less gain, you could add a bit in front.

[antonis]

Not because that, but I was thinking about the op-amp buffer stage. What if I turn it into a boost stage? Is it too much for this circuit?

Below is what said above..

By making R10 470k and IC1A with gain of that of Q2 stage, he can delete both Q1 & Q2 stages..
(with extra bonus IN-OUT been in phase..)

[Elijah-Baley]

https://www.premierguitar.com/diy/pedal-projects/boss-ds-1-mods
https://www.csguitars.co.uk/ds1-mod
https://www.instructables.com/Modify-Your-Boss-DS-1/
and of course: https://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf

Thank you antonis. I think I knew all of them. I'm collecting pages and note about all the possible mods by whoever.
I'll report soon not every single mod or package of mod, but a sort of instructions about all the mod of the critical parts.

One thing is sure. Dual op-amp version.
Not because that, but I was thinking about the op-amp buffer stage. What if I turn it into a boost stage? Is it too much for this circuit?

I'd say, yes, it probably *is* too much for this circuit. That Q2 gain stage has +35dB, so there's already a lot of boosting going on ahead of the op-amp.
But yeah, why not? Turn the DS-1 into a high gain monster pedal! Alternatively, if you modded the Q2 stage for less gain, you could add a bit in front.

Yes, I noticed that a sort of "fat mod" by Muzique.com is to increase the 1k, this pairs the bass and the treble response of the boost stage, but cut a lot of boost, too. If you mean this I could try to cut the boost of the Q2 stage, and to turn the buffer op-amp stage into a boost.
It was this what you meant, right?