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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Shiny_Beast
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Post by Shiny_Beast »

I've tried muching around with the input buffer tranny on my MIJ, I didn't like the change, overdriving that first transistor is probably what separates the ds=1 from a lot of other "clip to ground" pedals.

I'd like to build a

mu-amp -> 741 -> GE diodes to ground

as kind of a ds-1 killer. Put some eq trimming in the feedback path like a lot of the booteek pedals do these days. I think a lot of the charm of the ds-1 is the pick attack and dynamics you get and I suspect having that buffer there is responsible for a lot of it. If it wasn't for that rediculous tonestack I'd still keep it in my case as a problem solver.

Renegadrian
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Post by Renegadrian »

Modified a DS-1 these days, I had the Wampler classic jcm he wrote at premierguitar and the phlat mod from brett miller...I love that mod!!! I just found out I didn't put anything in the R17 spot after I took it off, it sounds better to my ears, some put a 22k there (Wampler wrote a 15k) but it sound better without!!!

candletears7
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Post by candletears7 »

I have a MIJ DS-1 and I HATE that BMP tonestack. No mids, no punch or grind.
I'm thinking of fiddling around with the R/C network or just bypassing the tonestack altogether and linking it straight to the level pot.
Anyone came up with an effective way to restore midrange to a Japan DS-1 before I get into it?

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Groovenut
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Post by Groovenut »

Try the tonestack mods used here, or maybe the whole thing. I liked it.

http://www.freestompboxes.org/viewtopic ... 92#p188996

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Post by candletears7 »

Man. That's such an improvement. Thankyou.
Anyone with an MIJ DS-1 needs to change C11 to 47n.

Xavier
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Post by Xavier »

I just bought a DS1 for 30€ and spent a couple of evenings changing components, until I came up with something usable (for me at least !!)
. Here's a video I made to illustrate how it sounds.

I've called the "hair metal" mod :D

[youtube]https://www.youtube.com/watch?v=czmLQ9z ... 9kweXM6PuQ[/youtube]

andregarcia57
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Post by andregarcia57 »

Xavier wrote:I just bought a DS1 for 30€ and spent a couple of evenings changing components, until I came up with something usable (for me at least !!)
. Here's a video I made to illustrate how it sounds.

I've called the "hair metal" mod :D

[youtube]https://www.youtube.com/watch?v=czmLQ9z ... 9kweXM6PuQ[/youtube]
really great pedal sound the same!
which schematic of the changes?

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Post by Xavier »

Hi Thanks !!

It's in the video description. It's just a few changes

R7 180K
R13 2K
C10 0,047mF
10nF cap across the tone pot legs (the outer legs)
R35 2k2 (more brightness for the 5 mm LED)

I have tried removing one of the clipping diodes (just one) and there's a nice volume boost, as long as less fizz. If you do this, the cap across the tone pot is not needed.

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Post by Tone-Analyst »

As much as most people dislike the DS-1 nowadays, I find this particular pedal to have a great vintage rock sound with the tone at zerro. (Sounding too dark of course) As i raise the tone control, the frequency is way too high. I would like to try a larger signal cap on that spot. Now my question is, which cap is it C10, C11, C12 probably? And is there a value you would recommend? If it helps, the tone control on my OS-2 is the perfect frequency. Thx!

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Post by Tone-Analyst »

Oups.. made a year later according to bossarea:
The unit with serial number 385700 was produced January 1984.

candletears7
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Post by candletears7 »

Here is a range of information


viewtopic.php?f=11&t=512&start=200

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5thumbs
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Post by 5thumbs »

Sorry I've been so distant for so long. I went through a huge upheaval in my life, so time for modding was non-existent for a very long time. Today was the first day I built anything music-related in almost 4 years.

From mid-2010 to early-2013, I was putting most of my efforts into saving a failed marriage. It didn't work out, proofed as of 2013. As if that wasn't enough of a life-challenge, I came down with full-blown fibromyalgia in early 2013...

... at the same time I got laid-off in the worst-ever job market. Even my multi-decade tenure with top tech-companies couldn't save me. Oh, and I divested my miserable, unrecoverable ex-wife at the time I got sick and unemployed, which did not help matters.

I spent over 18 months unemployed as my doctor struggled to treat my fibromylgia. (Fibro hurts *bad* when it's untreated.) I now work as a 911 dispatcher. Interesting work, but 12-hour shifts are not conducive to mod-work. Noble work, but hard to adjust to.

Moving forward, my intention is to test and deliver the last few mods I've come up with and deliver them in one, last version of the DIY-DS1-doc. After that, the "Build Your Own DS-1 Distortion" document will remain static/as-is.

Writing this is a victory, given the circumstances of the past years. Given my physical and work conditions, I don't have much time for answering posts/messages, so please understand. I will try as I am able, but on the positive side, I reckon that most of the questions that people would have me answer can be well-fielded by the other folks here on FSB.

I'll pop in and respond as I can, but I can't promise any service-level at this point.

Thank God for Leo Fender, Les Paul, Johan, and amplification. We are all better for their efforts. :applause:

Thank you and good night,

5thumbs
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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5thumbs
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Post by 5thumbs »

Koreth wrote:
5thumbs wrote:First of all, good analysis and thank you for it. I'm not real solid on the science of why the R6 changes produces the perceived change in bass response. Part of me wants to be lazy and fall into the "higher input impedance causing more pickup loading, hence more bass and presence" stuff...but I'm not convinced that's the right explanation to just blindly accept.) I'm going to read over your post again later and think about it (provided I get some time in the Tech Cave tonight.)
Truthfully, I'm not sure how much of an effect the filter created by C3 and R6 has on the overall tone. Looking at the graph for a high-pass filter, you have a decade in frequencies between the -3dB corner frequency of the filter and the point where the curve ends and you have no attenuation. So with a corner frequency of 33.9Hz, you have a frequency range of 33.9Hz to 339Hz where you have at least some attenuation between 0dB and 3dB. That's certainly a wide enough range to encompass most of the fundamental frequencies of the guitar's open strings, pretty much ending on the high E (E4=329.6Hz). But in that decade, there's only 3dB of attenuation at most. I was of the understanding that 1dB was about the minimum change the human ear can hear. I wonder if the gain provided by the op-amp is effecting this somehow, by somehow magnifying the difference between the highs and lows of the guitar signal, not just the overall signal level.
5thumbs wrote:OTOH, transistors are notorious for being non-linear in their amplification of frequencies in the human-audible range. (This is one of the reasons I usually think of opamps for boosting gain, rather than transistors...and yes, I am lazy. :) ) The re-biasing of Q2 appears to eliminate a lot of treble boost (a.k.a, frequency-dependent gain), so it might be that we are getting a treble cut and calling it a bass boost.
I really wish I understood transistors better, as then I could dig into data sheets and draw up graphs for how the Q2 stage is operating, like I can with a vacuum tube triode. To be fair, a triode amplifier can be non-linear in it's amplification of frequencies in the human audible range to, depending on how it's set up In a cathode biased triode, gain is much lower than it could be, due to cathode current feedback introduced by the voltage drop across the cathode resistor. That's why you'll sometimes see a capacitor in parallel with the cathode resistor; the charging/discharging action of the capacitor as the cathode voltage fluctuates helps to stabilize the cathode voltage, getting some of the stage's gain back. But this ends up creating a filter which causes the tube to have more gain at higher frequencies than lower ones. The only way around that is to a) either use a large enough capacitor, that the knee of the filter is below the lowest frequency of interest, or b) use a diode or diodes to get the voltage drop needed to bias the tube, since the diode's voltage won't fluctuate with current.

I hesitate to try to figure out the Q2 gain stage with tube knowledge more than I already have, as a) I'll eventually start Doing It Wrong as tubes and transistors have different behavior, and b) it'd be veering the thread away from the topic of tuning a DS-1 for maximum awesomeness of tone.
Cheese-and-rice, you should be talking to RG Keen and not my sorry ass! I'm an old IT/CompSci grad, so oscilloscopes make me cringe but old neon-sign transformers make me throb. *tremors*

I can solder, braze, and weld...

... just not at the same time. XD
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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Post by guiltyspark »

I had a dead newer (5223 chip) DS1 come in, turns out the chip was toast. I didn't have another SIP chip handy so I used a DIP8 adapter. First I put in a trusty TI 4558. Sounded like crap, I thought something else was wrong with the pedal. Very distorted sounding, not in a good way. Tried a TLE2072, same thing, distorted and mushy. Next I tried a TLC2262. The DS1 sounds very good with this with NO other mods, surprisingly. Sounds great in my rig anyway, crunchy and tight with a good balance of high/mid/low, mids might be cut a little. Setup is a LP Custom to DS1 to Bogner Uberschall on clean channel. I tried some of the "vintage DS1" cap changes after installing this IC and it made the pedal sound worse IMO. I haven't heard of this chip being used so give it a shot. Compared to a stock Japan made DS1, the Jap model has more lows but the honky, funky mids of the newer DS1 is gone. YMMV if your DS1 has extensive mods. The similar TLC2272 sounds good as well. And if you use one of the Brown Dog adapters, watch your clearance BEFORE you solder it in. I didn't. You can use a Mill Max SIL strip and mount the adapter sideways.

Also had a dead SD1 come in from the same guy, he must have used a totally incorrect power adapter. This SD1 was DEAD, no led, no signal. Turns out protection diode D1 was shorted and jrc4558 was dead. LED worked and signal passed as soon as I changed d1 for a 4001. Installed IC socket and new 4558, sounds good now. The SD1 is very much like a TS9. I might mod it a bit, maybe swap a cap and let some more low end through.

And 5thumbs, sorry to hear about the upheaval and illness, I hope things are getting better. I just want to say again what a great DS-1 document you put together, very informative. I've built hundreds of pedals but haven't messed with modding Boss pedals too much, so it's all new info to me.


Guiltyspark

loupy31
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Post by loupy31 »

Hi Guys,

I picked up a DS 1, from a Garage sale, I took it home and ran it through my fender twin basically to see if it was working, sure enough it work as expected, So I decided to do the Keeley Ultra/seeing eye mods.....I had all the parts so there was no waiting.

Ok , I completed the mod as per web information.

I tested the unit, huge difference , all functions worked.

I have one problem which is driving me nuts trying to solve it, I use a lespaul, with the Vol and Tone on the guitar all up full, I found when I hit the strings hard, the sound, is compressed for a split second then comes up to set Vol. this drop in the note is almost like a switch ....Pluck a note hard, huge compression for a spit sec. then normal vol.

Sounds like the signal is to much for the into, tried with other guitars and amps, same thing

Any help would be great,

Thanks Loupy31

PeddlePedalsw/Petals
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Post by PeddlePedalsw/Petals »

Question...

The Boss DS-1 sounds too compressed even after I have removed D4 and D5... Is there anything else I can do to make it sound more open? Also, I am trying to get more mids... I heard that lowering R16 or changing C11 will change the mids. How do these two differ? Thanks!

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Post by EmmG »

Compare the Ds-1 schematic to to a Big Muff, the same mods apply. The tone stack has 2 resistors and 2 capacitors you can change to flatten things a bit, all the way to a huge mid boost.

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Post by cacophony »

Regarding Brett Miller's Mondo-MIJ Mod, what's the best substitute for 2N3859A transistor?

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Post by chuckusa »

Quick question, How can I get the volume to come back up a bit after modding with w few ge 1n34a's and after performing the AMZ fat mod? Which resistor and what values?

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Post by dv8r601 »

chuckusa wrote:Quick question, How can I get the volume to come back up a bit after modding with w few ge 1n34a's and after performing the AMZ fat mod? Which resistor and what values?
^^^^Just a tip, That sounds kinda DEMANDING^^^^
BUT since I'm such a nice guy, I'll bite.
First off Lets find out which ones you've installed, where they came from, what they look like, And if you can operate a DMM,the Vf(diode setting) of said diodes
I ask bc I have a few legit Motorola 1n34 and they hover around 325-380 mV, I have a few batches of those eBay chinese "1n34a" that are really Si schottky and they are nearly half that of the real ones at 200-275 mV.
now to solve:

Normally that's the cost of using Ge diodes, the Vf is really low(>375mV) so unless you can fix that, your gonna cut way more of the volume.
many ways to go about this, 1) double up ge diodes by adding another in the same direction behind each one, thus lifting the Vf and still retaining the softer knee they yield. 2) piggy back them with a diode that has a higher Vf Like 1n4001, 1n4148, etc 3) carefully go thru this thread bc I'm pretty sure its in here. Its better to read everything and I'm 100% you'll get the answer your looking for, this place has Thousands of highly knowledgeable members that are nice enough to share.

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