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DIY Stompboxes => Building your own stompbox => Topic started by: 5thumbs on January 29, 2008, 10:29:52 AM

Title: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on January 29, 2008, 10:29:52 AM
Greetings everyone!  Miqbal and I have been working together on this document for the past couple of weeks.  In a nutshell, it contains an accurate schematic reverse-engineered from actual DS-1 pedals, as well as a true-bypass version of the DS-1 derived from the stock schematic.  In addition to the schematics, it contains PCB layouts and build information so you can build either a stock DS-1 or true-bypass DS-1 from scratch.

Please note that this document provides information regarding the post-1994, dual op amp DS-1, not the "vintage" DS-1 based upon the TA7136P.  We are considering adding "vintage" DS-1 build information at a later time, but this initial version focuses on the post-1994 DS-1.

Aron generously granted us permission to host this document here at diystompboxes.com.  (Thanks Aron!)  You can view the file here: http://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf.

Please post any questions or comments you may have regarding this information in this thread.  If you find errors in the document, please e-mail me with the corrections and I'll take care of updating the document.

Thanks!
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: audioguy on January 29, 2008, 02:19:10 PM
WOW fantastic! Can I assume that IndyGuitarists mods can be implemented on this unit?
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: gaussmarkov on January 29, 2008, 02:35:49 PM
now that is a project file!  :icon_cool:  great work.

thanks very much, paul :icon_biggrin:
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: beatstrat on January 29, 2008, 02:54:33 PM
Nice work.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: dxm1 on January 29, 2008, 03:15:23 PM
One question - the OpAmp pins are labeled opposite the data sheet. Are the pin numbers correct, or the input polarities?

EDIT - I should be more specific. The first OA in the "True Bypass" schematic shows pin 2 as the non-inverting input. This is opposite the data sheet. Pin 5 is correctly shown as the non-inverting input of the second device.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on January 29, 2008, 03:29:56 PM
WOW fantastic! Can I assume that IndyGuitarists mods can be implemented on this unit?

Miqbal and I tried to keep the plans as true to stock as possible (right down to using the correct color codes for wiring on the 'Stock DS-1 Wiring' diagram.)  The true-bypass implementation lops off the input/output buffers and switching flip-flop circuit, but other than that, it is as close as we could come with using DIP-8 op amps.

So most DS-1 mods you find on the Internet should work with both the 'Stock DS-1' and 'True-Bypass DS-1' layouts.

Dave, you were correct about the non-inverting input label on IC1A on the 'True-Bypass DS-1' schematic.  I made a labeling error, which I've now fixed.  The corrected document has been posted at the same URL, http://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf.

Thanks!
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: niopren on January 29, 2008, 05:14:44 PM
 :icon_eek:

excellent

great job!!!
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: miqbal on January 29, 2008, 10:47:48 PM
5thumbs,

It's nice to hear from you again.... inside the forum  ;D
Once again... great job, dude!!
I hope I will have had populate the board at the end of the week ;)

Guys,
All of you here have been so helpful and so inspiring. Thanks to you all!!


Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on January 30, 2008, 11:37:18 AM
Everyone:

There was a correction to both the True-Bypass and Stock DS-1 schematics/parts list last night.  C8 is supposed to be 0.47uF/50V, not 1uF.  (C8 was 1uF in the vintage DS-1, but 0.47uF in the post-1994.)

Apologies for the oversight, but we've corrected the document and uploaded it to the same location: http://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf.

If you've already downloaded the document, please download the latest version.

Thanks!
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: GravityRobert on January 30, 2008, 03:00:10 PM
 :D That's wonderful, just what I was looking for  :icon_cool:
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: suprleed on January 30, 2008, 05:24:01 PM
Great job!  Very thorough and complete.  This will come in very handy.  :)
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: jimbob on January 30, 2008, 05:35:10 PM
Im super impressed!!!! I wanna go in on a project like this with someone. Maybe for the sd-1 or something else. Huge thanks!!! It makes me wanna buy a ds-1 just to mess with it ect..

James
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on January 30, 2008, 11:29:45 PM
Im super impressed!!!! I wanna go in on a project like this with someone. Maybe for the sd-1 or something else. Huge thanks!!! It makes me wanna buy a ds-1 just to mess with it ect..

James

Thanks.  I've got old SD-1 service papers as well, but given its similarities to the Tube Screamer family (and the fact that R.G. has documented its details so thoroughly), I'm holding off on doing a similar document for the SD-1 at this time.  Besides, I've got to get some building and playing done before I try again to become Roland Corp's least-competent (and least-compensated) freelance technical writer.  :)

If anyone is interested in the tools used to create this doc, here's the quick list:  1) Eagle CAD (used by miqbal for his schematics and layouts); Visio 2007 (I used this for my layouts, schematics, wiring diagrams and drilling templates); 3) Word 2007 was used to create the build document and publish it to PDF format.  Other than that, it took a week or so of Muhammad and I bouncing revisions and suggestions back and forth to each other by e-mail before we got a version we were happy with.

FYI, I've written a new appendix for this DS-1 doc that describes a mod to make the post-1994 DS-1 sound more like the pre-1994 "vintage" DS-1.  I'm going to put the mod in a mule DS-1 I've got hanging around to verify the results.  Once verified, I'll post an updated version of this doc with the "MIJ-Mod" in it.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: petemoore on January 31, 2008, 01:02:36 AM
  Will be interesting to see how the 'old and new' and the 'intermediate chronocologically' DS-1's compare.
  The first one I had was an old one, the other two were very different.
 
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on January 31, 2008, 03:41:57 AM
  Will be interesting to see how the 'old and new' and the 'intermediate chronocologically' DS-1's compare.
  The first one I had was an old one, the other two were very different.
 

The three post-1994 DS-1 pedals I have are all pretty similar, in that they are based upon the M5223AL.  I've been tempted to pickup a pre-1994 pedal for testing purposes.  But to be honest, from all the various sound clips I've heard on the Internet of the vintage pedals, they sound different, but not necessarily better than modded post-1994 pedals.

So while I was contemplating picking up a MIJ DS-1 for $85 the other day on eBay, I got curious about the differences between the pre- and post-1994 pedals.  After comparing miqbal's schematic with the 12-26-1980 schematic that is all over the Internet, I found 26 components that were either a different component value or missing on one or the other.  Ten of those 26 components were signal diodes and NPN transistors...all of which compare very closely to the parts in the post-1994 DS-1.

After researching what the remaining 16 components did in their respective circuit positions, I narrowed the potential mod list to 6 components that could be easily changed and steer the tone of the post-1994 DS-1 closer to that of the vintage pedal.  In the new appendix, I go through all the differing components and give my reasons for why I believe some should be left out of a "vintage" mod on a post-1994 pedal.  While it's not possible to completely convert a post-1994 pedal to pre-1994 at a component and circuit level, it does appear possible to get the two pedals closer in terms of tone.

But all that is theoretical at this point.  Once I get the vintage, "MIJ-Mod" built, I'll be able to judge if the mod is worthwhile or not.  I'll have some sound clips to share at that point as well.

I've got a 4th DS-1 on its way to my shack, so I'm hoping it's the "new" DS-1 that is rumored to have a new op amp in it.  My last two new DS-1 pedals still had the M5223AL in them, but once I get my hands on the alleged "new" version, I'll be interested to hear how it differs from the post-1994 pedal.  I won't be able to compare it to a true MIJ DS-1, but I'll post sound clips of the MIJ-Modded post-1994 for the vintage pedal owners to judge.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on January 31, 2008, 12:57:56 PM
OK, temptation won out and I've got an MIJ DS-1 heading my way now.  Rather than doing a theoretical replacement mod based purely upon schematic research, I'll now tune the post-1994 MIJ-Mod to make it closely approximate the sound of my pre-1994 DS-1.

I'll update y'all once I've got the mods and side-by-side testing done.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: WGTP on February 01, 2008, 09:43:28 AM
Great stuff.  I know this has come up before, but the 47pf cap in the Keeley Mods looks like to me that it should be 470pf or even 4.7n.  I don't think 47pf is going to do much.   :icon_cool:
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: miqbal on February 04, 2008, 10:25:18 AM
Folks, stock-layout status now is: verified

Spent my weekend building this stuff:

I decided to use my Boss HM-2 enclosure to put this stuff for its new home. I bought the HM-2 from a local junk store several months ago. It was in a pretty bad shape. I fixed it, but I don't like it :P
I salvaged some of its components, especially the trannies and the ceramic caps on the FET-switching circuitry

Rather than populating all the components at once, for the first step, I simply populated only the main distortion circuit, i.e, no input/ouput buffer, no FET-switching and no Keeley's Mod. After making sure that everything is OK for the main distortion circuit, I continued to populate the whole rest components.
The FET-switching was highly unstable at first. It took me hours to figure it out. After having some trial and error, I finally found out that the caps on the switching circuitry (the 470p & 220p) were the trouble maker. I don't know which one is, since I simply replaced them all with a brand new ones  :icon_mrgreen:





This PCB has been heavily "abused" ;D: I've dealt with lots of (...and I said lots of) soldering and de-soldering process and lots of troublesome solder bubbles (I hate them for sure :icon_evil:). Well, too many mods to try :icon_wink:
I think, for a DIY level PCB, the ground pouring on the layout is just too much.... or maybe too close to the pads ??? Maybe I have to follow Gauss's suggestion: put an order from a PCB manufacturer!
But HEY.... it works ;D

I have to cut the top of the PCB, to accommodate the DC-jack, since the original DC-jack of HM-2 is not a board-mounted type. A picture of a currently manufactured DS-1 pcb is HERE (http://www.monteallums.com/images/DS1_PCB.jpg)

(http://i260.photobucket.com/albums/ii32/diystompbox/ds1/ds1_bottom.jpg) (http://i260.photobucket.com/albums/ii32/diystompbox/ds1/ds1_top.jpg)




These are some pics for the semiconductors. I even salvaged the HM-2 Germanium diodes!


(http://i260.photobucket.com/albums/ii32/diystompbox/ds1/opa2134.jpg) (http://i260.photobucket.com/albums/ii32/diystompbox/ds1/n5089.jpg) (http://i260.photobucket.com/albums/ii32/diystompbox/ds1/k30a.jpg)

(http://i260.photobucket.com/albums/ii32/diystompbox/ds1/clipping_diode.jpg) (http://i260.photobucket.com/albums/ii32/diystompbox/ds1/c945.jpg) (http://i260.photobucket.com/albums/ii32/diystompbox/ds1/c732.jpg)






The candidates for the fx "processors": (clockwise from top-left corner) TL072, LM358, M5218A, JRC4558, M5223AL, and JRC022. I forgot to put the NE5532 in the picture.

(http://i260.photobucket.com/albums/ii32/diystompbox/ds1/ic.jpg)



I'm unable to try out the M5223AL (SIP). The best sounding chip is, for sure, the Burr-Brown OPA2134. The closest to the OPA2134 (probably the same, according to my ears) is the LM358, both are like magic to this circuit. The other chips are absolutely AWFUL.
5thumbs, let me know your opinion about this LM358 :icon_exclaim:

Guys, I always got trouble when posting images inside a post, so please tell me IF it just happened again... :icon_redface: (they looks OK on my computer, though)
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on February 04, 2008, 05:11:19 PM
Nice looking build, Muhammad.  :)  Your PCB looks good and will work great in more recent BOSS enclosures with the PCB-mounted power jack.

I've never tried the LM385N in a DS-1.  In fact, I don't have any in my chip stash either.  I'll have to pick one up and give it a shot side-by-side with a M5223AL-equipped DS-1.  I personally run OPA2134PA chips in all my DS-1 pedals EXCEPT for the one post-1994 with the MIJ-Mod.  If the LM385N sounds close to the OPA2134PA, then I'll add it to the list of good-performing op amps for the post-1994 DS-1.

FYI, I've also got my testing completed for the MIJ-Mod.  I'll be posting more about it momentarily.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on February 04, 2008, 05:22:06 PM
Everyone:

I've updated the build doc with information about a new mod (the "MIJ-Mod") that makes the post-1994 DS-1 sound remarkably similar to the pre-1994 MIJ DS-1.

The new sections are:

- Brett Miller DS-1 “MIJ-Mod”

- Appendix B: How Do I Modify My Post-1994 DS-1 To Match The Original DS-1?

The 'Brett Miller DS-1 “MIJ-Mod”' section provides information on how to perform this simple, yet great sounding mod to your post-1994 DS-1.  Appendix B give you background information about the component-level differences between the post-1994 DS-1 and the pre-1994 DS-1.  Appendix B also provides commentary/analysis about the details and potential impact of each component difference.

You can download the updated doc from the same location as the original: http://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf.

So if you have a stock, unmodded post-1994 DS-1, three capacitors stand between it and the vintage DS-1 sound.   :)

Good luck!
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on February 04, 2008, 05:53:11 PM
Link to the new post, in which implementation details of the MIJ-Mod are given: http://www.diystompboxes.com/smfforum/index.php?topic=64927.0.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on February 08, 2008, 01:17:27 PM
Folks, if you're building a DS-1 from this doc, please check the value for C8 in the 'Stock DS-1' and 'True-Bypass DS-1' schematics.  C8 is supposed to be 0.47μF/50V for the post-1994 DS-1 and 1μF for the MIJ-Mod and MIJ-Mod PLUS DS-1.

We had some confusion early on about this value.  Unfortunately, the value for C8 remained documented at 1μF in many of the versions of this doc so far.  I think I've finally got all this worked out, so please grab the latest version of the doc to pick up the latest corrections.

Sorry for the "version hell", but this often happens when you have multiple contributors working on a technical document (who have busy full-time jobs.)  :)

-Brett
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on February 29, 2008, 03:25:32 PM
Greetings once again!  I've come up with the third and likely final mod in the MIJ-Mod series.  It's called the "Mondo-MIJ" and it is a high-fidelity version of the "MIJ-Mod" that builds upon the previous two "MIJ" mods.  The resulting distortion is really exceptional, particularly considering that it is coming from the humble DS-1.  I've demo'd the prototype to a couple of my guitar buddies and they were very impressed with the Mondo-MIJ by itself.  They were especially gracious towards it when comparing it to the stock pre-1994 DS-1, stock post-1994 DS-1 and MIJ-Plus DS-1 pedals I let them play side-by-side with the Mondo-MIJ DS-1.  (I'm now building additional Mondo-MIJ DS-1 pedals for them...an understandable consequence and a flattering result at the same time.)

The original “MIJ” mod was designed to replace only the minimal number of components necessary to make the post-1994 DS-1 sound like the pre-1994 MIJ vintage DS-1. The “MIJ-Plus” mod was designed to remove some of the “fizz” from the “MIJ” mod by increasing the proximity to clip in the D4/D5 clipping diodes. The “Mondo-MIJ” mod is designed to bring a higher fidelity sound to the “MIJ”-type mods through the use of film capacitors, an upgraded op amp and a more sophisticated clipping circuit. Admittedly, this is probably the last of the “MIJ”-type mod series. To extend the mod much further than the “Mondo-MIJ” will take the pedal in a direction that will likely be inconsistent with the tone shape and note articulation that endear the original MIJ DS-1 (and hopefully “MIJ” modded) pedals to guitarists worldwide.

You can find the "Mondo-MIJ" mod instructions in the 2-26-2008 version of the 'Build Your Own DS-1 Distortion" document located here: http://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf.  Pages 18-21 are the specific pages related to the "Mondo-MIJ".

NOTE:  If you have questions how to wire "Part 3" of the Mondo-MIJ, please post on this thread and I'll answer them as best I can.  The new clipping circuit in the "Mondo-MIJ" is a bit more complex than your average "diode swap" mod, but the resulting distortion is well worth the effort.  Jack Orman's articles on alternative distortion saturation controls are to be thanked for giving me the inspiration for the clipping circuit mod in the "Mondo-MIJ".  (Thanks, Jack!)
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on March 19, 2008, 03:27:37 AM
New minor mod to report today, the "PHLAT" Mod.  This mod is an alteration to the low-pass and high-pass filters that feed the TONE control of the DS-1.  The intent of this mod is to give the user the option to switch between the stock, scooped-mids tone and a flatter tone shape that will help keep the tone full-sounding at lower DIST settings.

The stock DS-1 TONE control has a low-pass filter with a corner frequency of 234 Hz and a high-pass filter with a corner frequency of 3290 Hz.  This produces the classic DS-1 scooped mids tone that allows the harmonics produced by the clipping diodes to be more prominent, giving it a heavily-distorted sound.  The PHLAT Mod moves the corner frequencies of both the TONE low-pass and high-pass filters to 1064Hz.  This change results in the mid frequencies to jump out more, resulting in a noticeable volume increase, as well as boost in sustain.  The resulting distortion is less harmonically rich than the scooped tone, but has a more vintage amp tone that works well with blues and country riffs at lower DIST settings.

I've added the PHLAT Mod to the 'Build Your Own DS-1 Distortion' doc and you can find it in the usual place: http://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: drewl on March 19, 2008, 08:22:58 AM
Hey, nice work.......I read the doc. so I don't have any stupid questions.
You answered them all!
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: flo on March 19, 2008, 09:54:23 AM
Very nice document. Thanks a lot! I wanted to build one and fiddle with it. This will help me along perfectly!
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: mattpas on March 19, 2008, 10:46:15 AM
How close is this design to the Tonepad FX DS-1 PCB?
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on March 19, 2008, 11:04:58 AM
How close is this design to the Tonepad FX DS-1 PCB?

There are quite a few differences between the True-Bypass DS-1 in the 'Build Your Own DS-1 Distortion' doc and Francicsco's DistoUNO DS-1 work-alike.  If you compare the schematic for the TB DS-1 on Page 8 of http://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf with the DistoUNO schematic, you'll see there are a number of differences in the component values.

Why the differences?  Well, Francisco was designing a PCB that would allow the builder to use either a TA7136P (the original DS-1 single op amp) or a 4558-type dual op amp, which by itself is a very cool feature.  When miqbal did the schematic/PCB for the Stock DS-1, he wanted to exactly match the post-1994 BOSS DS-1, except use a DIP8 dual op amp pinout.  When I did the TB DS-1 schematic/PCB, I wanted to preserve the stock layout/component numbering so that folks could make a TB version of the DS-1 that was still moddable with all the DS-1 mods floating around on the Internet.  The TB DS-1 schematic preserves everything in Miqbal's Stock DS-1 schematic, except it removes the input/output buffers and the flip-flop switching circuit.

I've never built Francisco's DistoUNO, but I'm sure it rocks (just like everything else I've bought from him.)  The DistoUNO is a great choice if you want to build a DS-1 with the original TA7136P op amp.  Miqbal's Stock DS-1 is great if you want to build a BOSS DS-1 replica that uses the more readily available DIP8 dual op amps.  My TB DS-1 is great if you want a true-bypass DS-1 that is very nearly stock, plus it has the option to incorporate Keeley's Seeing Eye/Ultra mods included right in the PCB.

So in the end, you'll have to decide which is best for you, but that's a quick rundown of the differences between the three DIY DS-1 layouts.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: drewl on March 19, 2008, 11:52:05 AM
Okay, I do have a stupid question.
What is the "seeing eye mod"?
Is it using an LED for a clipper that is viewable from the top so it will light up as it clips?
just my guess thanks......hard to keep up with all this wackiness.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on March 19, 2008, 01:10:26 PM
Okay, I do have a stupid question.
What is the "seeing eye mod"?
Is it using an LED for a clipper that is viewable from the top so it will light up as it clips?
just my guess thanks......hard to keep up with all this wackiness.

Yup, that's part of it, but there are additional cap changes as part of that mod.  On Pages 13-15 in the BYODD doc (http://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf), there are full details regarding Robert Keeley's Seeing Eye and Ultra mods.  In a nutshell, Mr. Keeley drills out the 'O' in the 'TONE' lettering on the DS-1 and installs a red LED in place of the D5 clipping diode.  The fact that you can see the D5 clipping LED illuminate in the 'O' of 'TONE' is the "seeing eye" part.

For the Keeley Ultra mod, he replaces the D4 diode with a series combination of a red LED and 1N4148 diode.

As I mentioned before, there are other cap/resistor changes that make up the rest of those mods, but you can read about those either in the aforementioned BYODD doc or on Keeley's website at http://www.robertkeeley.com/audio6l6/dstech.html.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: DiamondDog on March 19, 2008, 10:22:46 PM
Great work, Brett and Miqbal!

Can I make one suggestion regarding the 'straight' DS-1 layout, though. The way it is set up at the moment, you have to heat up a pretty substantial area of the gound poor to solder effectively, and when you do it's a messy result. If your design program allows it, it is easier if you have a solder pad in and isolated from the pour, which is then connected to that pour. Confused? Let me try this way:

* = pour
o = pad
- and | = connections


*******
*******
**  |  **
**_o_**
**  |  **
*******
*******

That way you only  have to get the pad up to temperature, not a large pour, and you don't compromise connectivity. I hope that makes sense.

I use Eagle and it has an option to do it; I don't know what program you use.



Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on March 20, 2008, 02:36:17 AM
Great work, Brett and Miqbal!

Thanks. :)


Can I make one suggestion regarding the 'straight' DS-1 layout, though. The way it is set up at the moment, you have to heat up a pretty substantial area of the gound poor to solder effectively, and when you do it's a messy result. If your design program allows it, it is easier if you have a solder pad in and isolated from the pour, which is then connected to that pour. Confused?

Well, a little confused.  When you refer to the 'straight' DS-1 layout, are you referring to the Stock DS-1 layout or the True-Bypass layout?  Muhammad designed the Stock DS-1 schematic and layout on Eagle CAD.  I did the True-Bypass DS-1 schematic and layout using Microsoft Visio 2007.

The traces in the Stock DS-1 layout are, on average, bigger than those on the True-Bypass DS-1 layout.  Muhammad tried to match the trace shape and size of the original BOSS traces as possible.  (You can reference a solder-side image of the BOSS PCB here: http://i76.photobucket.com/albums/j23/overdrivespider/step03_05.jpg.)  One possible solution to excessive solder flow would be to apply a solder mask, as BOSS did with similar-sized traces on the post-1994 DS-1.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: WGTP on March 21, 2008, 11:37:44 AM
Very well done.   :icon_cool:

It appears to me that the first "gain" stage after the input buffer and switching is very similar to the Big Muff Pie stages without diodes.
Looking at BMP mods, the bias resistor from the collector to +9v varies from 10k to 15K, with some versions using different values in different stages.  This would seem to be a value to investigate as it effects the bias, gain and symmetry of the waveform.  Depending on the transistor being used, it may be optimally biased or not.  A 25k trim pot might be useful.  This is R8. 

Also the resistor from the emitter to ground R9, varies in the BMP from 100 to 680 (some mods bypass it).  In the DS-1 it is 22 which would seem to have increased gain and also limit the swing of the waveform on one side creating asymmetrical distortion, I think.

Has anyone experimented with this stage?

I guess the first op amp is a buffer between the BMP type stage and the "drive" stage or second op amp.  I haven't tried the DS-1 without diodes, but I suspect it will have lots of distortion from the op amp being overdriven before the signal gets to the diodes.  This is why the op amp selected has a significant effect on the tone.  Other suggested op amps, are the OP275, TLC2262, NE5532, 4559, TL052, etc. There are hundreds.   :icon_cool:


Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on March 21, 2008, 03:28:48 PM
Very well done.   :icon_cool:

Thanks. :)


I guess the first op amp is a buffer between the BMP type stage and the "drive" stage or second op amp.  I haven't tried the DS-1 without diodes, but I suspect it will have lots of distortion from the op amp being overdriven before the signal gets to the diodes.  This is why the op amp selected has a significant effect on the tone.  Other suggested op amps, are the OP275, TLC2262, NE5532, 4559, TL052, etc. There are hundreds.   :icon_cool:

I'll be rebuilding a couple of DS-1 pedals in the immediate future, so before I rip them all apart, I'll pull the D4/D5 diodes and see what they sound like with both the M5223AL and newer NJM3404AL with no clipping diodes.  I'll let y'all know what I find out.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: Andre on March 24, 2008, 06:51:39 AM
Thanks for a very nice and well documented project.

Here's some pics of the one I built in a Boss like enclosure.
(http://www.xs4all.nl/~jvcn0028/pictures/DS-1_Board.jpg)(http://www.xs4all.nl/~jvcn0028/pictures/DS1_Copper.jpg)
(http://www.xs4all.nl/~jvcn0028/pictures/DS-1.jpg)

André
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: ayayay! on March 24, 2008, 11:31:53 AM
NICE job Andre. 

Quote
Also the resistor from the emitter to ground R9, varies in the BMP from 100 to 680 (some mods bypass it).  In the DS-1 it is 22 which would seem to have increased gain and also limit the swing of the waveform on one side creating asymmetrical distortion, I think.

WGTP, educate me here:  BMP?  And why 22?  Seems like a rather random value.  Why not just bypass it?   
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: WGTP on March 24, 2008, 02:06:20 PM
I'm not an expert on these type of stages (or any other for that matter), but I THINK that the lower the resistance, the higher the gain and more asymmetrical the distortion.  I thought it looked familiar so I checked the BMP stages and there it was.  I think Boss wanted to drive the op amp stage pretty hard and 22 ohms provided what they were after.  By-passing that resistor probably provides no hope of a clean signal getting thru, thus limiting the possibilities for semi-clean tones.   :icon_eek:

I just recalled the AMZ Overdrive Pro has a similar first stage with a 150 ohm reisistor, but no cap parallel to the 470k resisitor.  This cap rolls off highs.   :icon_cool:
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: ayayay! on March 24, 2008, 02:32:46 PM
I'm sorry WGTP.  I wasn't spefic:  what does BMP stand for? 
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: DiamondDog on March 24, 2008, 08:56:58 PM
I'm sorry WGTP.  I wasn't spefic:  what does BMP stand for? 

"Big Muff Pi". You will find the BMP's single-knob tone control in a lot of circuits. Check out the workbench or whatever at Jack Orman's (http://www.muzique.com) site for lots of variations on it.
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on March 25, 2008, 01:10:48 AM
Thanks for a very nice and well documented project.

You're welcome.  I'm glad you found it helpful, as I use it often myself.

Here's some pics of the one I built in a Boss like enclosure.

Very nice build, André.  Looks cleaner than even BOSS makes 'em.  :D
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: DiamondDog on March 25, 2008, 11:54:18 AM
Great work, Brett and Miqbal!

Thanks. :)


Can I make one suggestion regarding the 'straight' DS-1 layout, though. The way it is set up at the moment, you have to heat up a pretty substantial area of the gound poor to solder effectively, and when you do it's a messy result. If your design program allows it, it is easier if you have a solder pad in and isolated from the pour, which is then connected to that pour. Confused?

Well, a little confused.  When you refer to the 'straight' DS-1 layout, are you referring to the Stock DS-1 layout or the True-Bypass layout?  Muhammad designed the Stock DS-1 schematic and layout on Eagle CAD.  I did the True-Bypass DS-1 schematic and layout using Microsoft Visio 2007.

The traces in the Stock DS-1 layout are, on average, bigger than those on the True-Bypass DS-1 layout.  Muhammad tried to match the trace shape and size of the original BOSS traces as possible.  (You can reference a solder-side image of the BOSS PCB here: http://i76.photobucket.com/albums/j23/overdrivespider/step03_05.jpg.)  One possible solution to excessive solder flow would be to apply a solder mask, as BOSS did with similar-sized traces on the post-1994 DS-1.

Sorry, "Stock" was the word I was lookign for, not "straight". I get confused at my age. Too many things in the 70s. No, I 'm not joking.

Muhammed mentioned somewhere else here on a DS-1 thread that he was having a bit of an issue with the soldering, and this could be why. It's not a matter of solder flow- it's a matter of trying to heat up the whole ground pour area.

If he's happy, then that's cool. Just thought I'd mention it.

Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on May 16, 2008, 01:31:04 AM
Howdy, everyone!

I added a new mod to the 'Build Your Own DS-1 Distortion' doc.  It's called the VR-MIJ.  You can read about it when you download the latest version of the doc: http://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf.

Here's the introductory text for the VR-MIJ:

"This mod started with Jack Orman’s “Fat mod for the Boss DS-1” article. My initial tests with this mod resulted in an increase in perceived bass and mid frequencies, due to the cut in treble boost from this mod. I wasn’t happy with it at first, as it reminded me of a fuzz pedal, which wasn’t on my pedal “to do” list at the time.

So after thinking about it more over the next day, I wanted to try combining the Mondo-MIJ mods (minus the clipping network), Jack’s “Fat mod” and MOSFET clippers in an attempt to increase the note articulation and cut the fuzz-like qualities of the pedal. I was VERY pleased with the result, which is why I’m presenting it to you here. Please meet the “VR-MIJ” Mod. (The “VR” stands for “Vintage Ripper”, while “MIJ” shows that it’s still part of the MIJ-Mod family in terms of other component replacements.)"
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: Jered on May 17, 2008, 06:19:01 PM
  All I can say is WOW!! You guys did some stellar work. Very inspiring. Great work guys.
  Jered
Title: Re: New Build Doc: "Build Your Own DS-1 Distortion"
Post by: 5thumbs on May 17, 2008, 11:17:23 PM
  All I can say is WOW!! You guys did some stellar work. Very inspiring. Great work guys.
  Jered

Thanks, I'm glad you like it.  Muhammad got the ball rolling by creating that exquisite stock DS-1 schematic and layout.  I got inspired by his work and did the true-bypass schem and layout.  Everything else came along in bits and pieces after that initial inspired outburst.