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BOSS DS-1?

JohnnyCrash
November 4th, 2009, 04:33 PM
I might be able to get my hands on a BOSS DS-1 for dirt cheap ($20 +/-).

1. What do you stombox gurus think of the DS-1?

Is it good, bad, or worth it if modded? Is it a worth picking up for $20 and tweaking?

2. What mods would you recommend I perform on it. I've got boxes full of parts waiting to be used.

pchilson
November 4th, 2009, 04:48 PM
I didn't like mine stock but after some changes it improved considerably.
I took my mods from here (http://www.premierguitar.com/Magazine/Issue/2008/Feb/Boss_DS_1_Mods.aspx).

Its been some time ago and I can't remember exactly which of the mods I did but I started minimally and liked it so I did not go further.

JohnnyCrash
November 4th, 2009, 05:27 PM
Cool.

I'm picking one up tonight for $15.

I've got boxes of diodes and LEDs. I might need to go to my local electronics shop to pick up more caps.

pchilson
November 4th, 2009, 05:34 PM
I think out of the box the DS-1 is sort of raspy sounding. At least to my ears.

I think I did this one with the idea that I would go further if needed but it smoothed out the sound so well I stayed put.

Vintage distortion tones
LOCATION CHANGE TO:
D5 LED
C3 .033µF
R16 1k
C11 .001µF

dantonel
November 4th, 2009, 06:29 PM
The Keely mod is also very nice for it as well and I think that it is on the Blue print Black market.

Faraldi
November 4th, 2009, 06:38 PM
IMHO is an awful pedal until it's worked on.

Then it becomes a fantastic pedal (depending upon what you do).

I have one that was worked on by Big Papa Mods and it's great. Completely musical tone rather than the stock "needles in the eyes" tone.

Buy it.

JohnnyCrash
November 4th, 2009, 06:59 PM
I was thinking of the following mods:

1. Adding gain by decreasing R13's value to 2.2k.

2. Adding midrange beef by increasing C1, C3, and C13 (all 0.047uF) to 0.1uF. Increasing C11 (0.022uF) to a 0.047uF... essentially just doubling these tone cap's sizes.

I might increase C2 (0.47uF), and C9 (0.47uF) to 1uF later, but for now I'm leaving them as-is.

I think all of these mods are also involved in the Keeley mod.

--

I wasn't sure what I was going to do about the diode clippers... maybe adding one on one side to make it assymetrical, IDK. For now, I'll leave them alone and see if I like the nature of the distortion after fattening up the tone (increasing cap sizes) and adding more gain (lowering R13).

I don't want to go full Keeley mod on this thing. I don't think noise will be an issue (half of his cap swaps are for noise), and I'm keeping away from the Keeley diode/LED swapping stuff for now... though I probably already have the diodes/LED's for them in my parts bin...

11 Gauge
November 4th, 2009, 10:02 PM
Everyone seems to have their own recipe, and I would argue that the well documented ones (like the Keeley stuff) really only serve as a starting point.

I'd also consider not going overboard, since many folks end up having to backtrack a bit, which can be a PITA.

My favorite mods of late center around the often overlooked Q2, which is biased waayyy too hard in stock form. This is where all of the icepick fizzies originate from, since this tranny is responsible for boosting the op amp into oblivion. Lotsa folks change the op amp and diodes, while most neglect Q2.

...The MOST CLEVER thing that I've witnessed done with Q2 is to replace it with a MOSFET, which basically converts it into a SHO boost. There's a guy who goes by cctsim on a few other boards who seems to have mastered this. Do some googling, and his techniques should pop up.

But the most comprehensive DIY DS-1 stuff is by the awesome Mr. Brett Miller, IMO. He can show you how to build one from scratch, how to turn a MIT into a near equivalent of a MIJ, as well as all of the popular internet mods. He also has a few of his own, and has done some really comprehensive stuff with clever clipping circuits. AND he is hip to modding Q2, which is CRITICAL. He goes by 5thumbs on at least one other forum, if you google him.

Brett has created a comprehensive DS-1 modder's wet dream document, and he updates it regularly (he's about to include cctsim's Q2->SHO mods soon). Here is a link to the latest PDF of it. (http://www.diystompboxes.com/smfforum/index.php?topic=76021.msg661441)

BTW - MF is supposed to have the DS-1 on sale for $30 brand new. So less of a need to scavenge around for beaters when you can get a nice shiny one for a few bucks more.

voided3
November 4th, 2009, 10:13 PM
I used to use my DS-1 a lot back when I was running a Kustom K200 with a pair of matching 2x15" cabinets. They can be very harsh sounding, but if you never turn the tone control past nine 'o clock or the distortion past three 'o clock, you're in the clear. Note that I was using it with a fairly dark sounding amp with lots of bottom; it's not a good pedal for small amps.

I prefer my OD-3 now for everything and frequently use it with no other effects for shows. Even then, it's the only overdrive on my board (I have reverb, wah w/ built in fuzz, a compressor, and an octavia, but I almost never use the fuzz on the wah). If the OD-3 and the DS-1 were amps, I would say the OD-3 is a cranked up Deluxe and the DS-1 is a modern voiced Marshall (kind of scooped).

Bhallguitar
November 4th, 2009, 10:57 PM
I didn't like mine stock but after some changes it improved considerably.
I took my mods from here (http://www.premierguitar.com/Magazine/Issue/2008/Feb/Boss_DS_1_Mods.aspx).

Its been some time ago and I can't remember exactly which of the mods I did but I started minimally and liked it so I did not go further.

I just did the "JCM" mod from there and it sounded 100% better. Thicker, less raspy but still heavy.

Scott Auld
November 4th, 2009, 11:03 PM
Hard to go wrong for $15.

Mumphrey
November 4th, 2009, 11:07 PM
I too did the "Vintage" mod and worked slowly from there. Took advantage of the 'raspyness' and turned it into a bad-ass Marshall in a box.

Avoid the Keely mod. It's serious hype. It sounds like arse.

11 Gauge
November 5th, 2009, 12:09 AM
I took my mods from here (http://www.premierguitar.com/Magazine/Issue/2008/Feb/Boss_DS_1_Mods.aspx).

Those mods aren't bad, but Brett Miller's are light years ahead of those, IMO. Brett is truly in love with the DS-1, whether it's replicating the MIJ as close as possible, or repurposing the DS-1 for certain amps (like with his Huevos Grandes mod). It really allows you to cut to the chase.

Brett also has sound clips for almost all of the mods covered, just to give a quick comparison of how they sound relative to one another. If nothing else, it's fun just to listen to all of the clips (He has three clips of each mod through three different amps, a Bassman, a 5E3, and a JTM-45 into a 1960TV cab).

Do yourselves a favor and cut to the chase - LINKY (http://www.diystompboxes.com/smfforum/index.php?topic=76021.msg661441)

Here's a taste of some clips:

Huevos Grandes into Bassman (http://freestompboxes.org/members/5thumbs/DS-1%20Soundclips/FB410%20-%20HG%20-%201.mp3)

MIJ Mod into 5E3 (http://freestompboxes.org/members/5thumbs/DS-1%20Soundclips/FD112%20-%20MM%20-%201.mp3)

Mondo MIJ Mod with Phlat Mod into JTM-45 (http://freestompboxes.org/members/5thumbs/DS-1%20Soundclips/MBB412%20-%20MMM_P%20-%201.mp3)

Original MIJ (unmodded) into 5E3 (http://freestompboxes.org/members/5thumbs/DS-1%20Soundclips/FD112%20-%20ORIG_MIJ%20-%201.mp3)

Vintage Ripper Mod into Bassman (http://freestompboxes.org/members/5thumbs/DS-1%20Soundclips/FB410%20-%20V%20R%20-%201.mp3)

Al Watsky
November 5th, 2009, 12:54 AM
I was using a Keeley moded DS-1 and a Keeley Moded BD2 on my board for a while.
The BD driving the DS sounded real good with a Tele thinline I have with a hummer in the neck.
I was checking it for a runout I did last week and with single coils. its a bit bright but not at all annoying. Wound up going with the Blackstone, which rocked.
Want to try the Stone into the DS or visa-versa, see if I can get some over the top shred out of that.

JohnnyCrash
November 5th, 2009, 12:59 AM
I too did the "Vintage" mod and worked slowly from there. Took advantage of the 'raspyness' and turned it into a bad-ass Marshall in a box.

Avoid the Keely mod. It's serious hype. It sounds like arse.



After reading what the Keeley mods are exactly - I think you're right - more on that below :)



My favorite mods of late center around the often overlooked Q2, which is biased waayyy too hard in stock form. This is where all of the icepick fizzies originate from, since this tranny is responsible for boosting the op amp into oblivion. Lotsa folks change the op amp and diodes, while most neglect Q2.

But the most comprehensive DIY DS-1 stuff is by the awesome Mr. Brett Miller, IMO... AND he is hip to modding Q2, which is CRITICAL. He goes by 5thumbs on at least one other forum, if you google him.

Brett has created a comprehensive DS-1 modder's wet dream document, and he updates it regularly (he's about to include cctsim's Q2->SHO mods soon). Here is a link to the latest PDF of it. (http://www.diystompboxes.com/smfforum/index.php?topic=76021.msg661441)

BTW - MF is supposed to have the DS-1 on sale for $30 brand new. So less of a need to scavenge around for beaters when you can get a nice shiny one for a few bucks more.



Unfortunately, they're a little more (on sale for $39.99).

I literally just got back from picking up this $15 DS-1 and it is practically brand new. The cardboard box hasn't even faded and its got all of the paperwork with it. Two minor scratches on an otherwise brand new, shiny DS-1!

I've read some of 5thumbs older posts on the subject, but didn't know he kept his dissections of DS-1's up. I also didn't know how well he's gotten into the DS-1 circuit. Very cool stuff!

11 Gauge, you already know how JCM800's get the rep for being fizzy. After realizing how much of that came from gain and coupling caps, and how much from overuse of the Pre/Gain knob - I think you know I'm now leaning towards Jack Orman's old "Fat Mod" for the DS-1 in reducing gain on Q2.

Keeley seems to have gone the caveman route and pumped the couplers while reducing clipping threshold (LED's in place of stock diodes), whereas Jack simply swapped two resistors on Q2 to get less fizz by driving it less... this seems like an experiment I tried with a 2204 JCM800 where I increased coupling caps and still encountered fizz (as well as a little more woof). Playing with the gain (same overall gain, but less at some stages and more at others) helped the fizz, and caps helped the body... seems like the right approach for this pedal too.

I've already built Jack's MOSFET clean boost and love it, so I think I trust 5thumbs and Jack more than the salesman Keeley.

--
SO

After reading that awesome article you linked (very cool article, by the way), I think I'll do my own sort of "Mondo MIJ" style in some ways. I don't care about it being MIJ vintage sounding... I want tons of gain and no fizz.

CLIPPERS:
Since I want a pedal with a great deal of crunch AND assymetrical clipping, I'm sticking with the stock low threshold clipping diode (1N4148's in mine) in one spot and a little higher in the other... still figuring that one out (I've got diodes coming out of my ears with the silicon grab bag in my garage).

MIDRANGE:
I'm gonna stick with a few cap tweaks, but not as many as Keeley seemed to push (again, half of his seemd to be for noise reduction).

I'm swapping C1. C3, C11, and C13 for bigger values.

FIZZ:
I will still replace R13 for more gain, but I will drive Q2 a bit colder a la Orman's "Fat Mod."

My only concern is the Mid cap swaps with the colder Q2 will result in too much darkness, but I'll see when its done and tweak as necessary from there. I test with a bright/thin Tele, a P-90 shorter scaled guitar (Gibson with P-90s), and a humbucking Gibson... but in the end, I'm mainly a Gibson P-90 and humbucker player.

--

Thanks to everyone for their input and experiences! Hopefully, I've narrowed down my personal mod list and can turn $15 into an even better deal! You guys are awesome. I love this forum.

I'll let you know how it sounds stock and how these mods improve (or don't improve) the sound in a few days.

telecat33511
November 5th, 2009, 02:08 AM
Here's a good guide chart n Boss's web site
http://www.bosscorp.co.jp/products/en/BD-2/images/intro_R_L.jpg
It's the overview chart
HTH

EdItEd: - always a day late and a dollar short:rolleyes:

11 Gauge
November 5th, 2009, 07:54 AM
Unfortunately, they're a little more (on sale for $39.99).

CLIPPERS:
Since I want a pedal with a great deal of crunch AND assymetrical clipping, I'm sticking with the stock low threshold clipping diode (1N4148's in mine) in one spot and a little higher in the other... still figuring that one out (I've got diodes coming out of my ears with the silicon grab bag in my garage).

MIDRANGE:
I'm gonna stick with a few cap tweaks, but not as many as Keeley seemed to push (again, half of his seemd to be for noise reduction).

I'm swapping C1. C3, C11, and C13 for bigger values.

FIZZ:
I will still replace R13 for more gain, but I will drive Q2 a bit colder a la Orman's "Fat Mod."

My only concern is the Mid cap swaps with the colder Q2 will result in too much darkness, but I'll see when its done and tweak as necessary from there.

I received MF's printed form of their Xmas catalog, and the DS-1 is indeed $30 - they're probably waiting to drop it on their website. More of a heads up for folks who are constantly tweaking these things (like me!).

Clipping diodes - you're on the right path, IMO. The threshold combos that I tend to like are obtained with about 650mV on one side (stock diode) and 750-900mV on the other. Brett has some thoughts on using cheapo transistors as diodes, but you can put pairs of diodes in series to get the different thresholds.

Midrange/cap tweaks - the BULK of midrange adjustment is with C3. Go bigger for flab, and much smaller to make the pedal brighter. IMO, the magical cap value is either .027uF or .033uF. Both set the stage for the frequencies that are increased with Q2.

...Yeah - Keeley and many others go kinda nuts with cap swaps. And most tend to use the same values in certain spots. C1 can be left stock - it's more for your bypass tone than anything. If you increase it, it can get flubby. C11 IS critical to midrange, since it's the treble side of the tone "blend" control. Keep enlarging it for more mids, or enlarge R16. I like .068uF, but some folks go much larger. C13 is again part of the bypass circuit as well as the effect circuit, so I tend to not alter it by much. Maybe increase it some, but not much (like .068uF).

...THE CAPS TO TWEAK (IMO) are C3, C5, C9, C11, C12. As far as most of the mods that call for 1uF in those slots, forget about it. If you're dropping gain, "quieter" caps aren't much of an issue. And any film cap will work fine. I avoid tantalums in the DS-1, and nonpolarized electrolytics make life a little easier. DO NOT use electros in slots like C8 (which must be adjusted if you alter R13) - it will sound like garbage when the op amp is driven harder. I never go lower than 2.7K-3.3K for R13, which means that C8 needs to be around 1uF. Make it a little smaller (.68uF) to tighten up the amount of bass that gets clipped. A good film cap is a necessity for C8 (if modified). Brett goes down to like 1K for R13 in a few mods - that's too low IMO. Increase the clipping threshold of D4/D5 to get some volume boost back (maybe as high as 1100mV) if cooling down Q2 drops too much signal.

Rebiasing Q2 does make things a bit more wooly, but C3 is THE KEY to tightening it up. Most folks go larger - this is the opposite of what you want to do (even with the stock Q2 bias).

Oh yeah - Brett (and most others) replace the op amp. The stock one (whether the Mitsubishi or NJM) are FINE if not driven too hard. Others will beg to differ, but putting in a DIP8 adapter and some hi fi chip (the OPA's, etc.) is completely unnecessary, IMO. The stock chips are a little fuzzy in all of the right ways, IMO. The metal crowd LOVES the Mitsubishi chip. I can see why - while swapping them, it is the undisputed winner, IMO.

Mumphrey
November 5th, 2009, 10:21 AM
Sorry for the hijack here, but...

11 Gauge, if you know the answer, could you please respond to my questions in the ultimate CS-3 mod thread.

Thank you.

JohnnyCrash
November 5th, 2009, 01:14 PM
OK, then I think I'm probably on this track:

1. Reducing Q2 bias (R6 to 150k and R9 to 1k).
2. Increasing C11 from 0.022uF to 0.047uF.
3. Increasing gain (no lower than 1800 on R13 with a 1uF on C8).
4. Keeping stock clippers and simply adding a switch to parallel in another diode with D4 (or D5). How much added headroom from going assymetrical should I expect?
5. Possibly reusing C11's 0.022uF for C3 if things are whoofy.

For #3 I was helped by this calculator:
http://www.muzique.com/schem/filter.htm



Clipping diodes - you're on the right path, IMO. The threshold combos that I tend to like are obtained with about 650mV on one side (stock diode) and 750-900mV on the other. Brett has some thoughts on using cheapo transistors as diodes, but you can put pairs of diodes in series to get the different thresholds.



This is my problem - I can't find a good list on diodes' clipping thresholds.

5thumb's document only covers a few diodes... I might only be switching D5 with an LED anyway.

Faraldi
November 5th, 2009, 01:29 PM
I was thinking of the following mods:

1. Adding gain by decreasing R13's value to 2.2k.

2. Adding midrange beef by increasing C1, C3, and C13 (all 0.047uF) to 0.1uF. Increasing C11 (0.022uF) to a 0.047uF... essentially just doubling these tone cap's sizes.

I might increase C2 (0.47uF), and C9 (0.47uF) to 1uF later, but for now I'm leaving them as-is.

I think all of these mods are also involved in the Keeley mod.

--

I wasn't sure what I was going to do about the diode clippers... maybe adding one on one side to make it assymetrical, IDK. For now, I'll leave them alone and see if I like the nature of the distortion after fattening up the tone (increasing cap sizes) and adding more gain (lowering R13).

I don't want to go full Keeley mod on this thing. I don't think noise will be an issue (half of his cap swaps are for noise), and I'm keeping away from the Keeley diode/LED swapping stuff for now... though I probably already have the diodes/LED's for them in my parts bin...



I'm pretty sure you will reduce gain by making R13 2.2K. I've been working with a local and fairly popular mod guy here in KC and the DS-1 he made for me has R13 changed to 2.2K, which, along with his other mods, made it less gainy.

In fact, it appears most of the gain nastiness is coming from the opamp.

On mine, I'm actually going to put the 4.7K back in on R13 so that I ADD gain. As it stands right now, I get the big gain tone in the last 25% of the knob, whereas I want to have it break up earlier.

Ben Harmless
November 5th, 2009, 01:43 PM
If I may be the devil's advocate here...

I think the DS-1 is poo-poo'd by a lot of folks, and unfairly. I like mine bone-stock, precisely because it's not the holy grail of organic overdrives. I mean, it wasn't meant to be, unless I'm mistaken.

Johnny, if you've already got that Guv'nor clone you built, what's your goal with the DS-1? I suppose if you wanted to turn it into a metal machine, that could be a way to go, but otherwise, why bother?

...Unless of course, you just like to tinker, which I fully understand.

The funny thing is that I visited proguitarshop.com (http://proguitarshop.com/) yesterday and up popped a video demo of the Lovepedal Eternity E6 (http://proguitarshop.com/store/overdrive-pedals-c-6/lovepedal-eternity-e6-p-1385). I listened for a few seconds and thought to myself "self, you can pretty much cop those tones with your stock DS-1." The Lovepedal is literally $200 more.

I welcome disagreement, but I've learned to trust my ears.

All this being said, I use my DS-1 largely in the first 3rd of the rotation of the gain knob. Beyond that, it does get significantly more fizzy than I care for.

Faraldi
November 5th, 2009, 01:50 PM
If I may be the devil's advocate here...

I think the DS-1 is poo-poo'd by a lot of folks, and unfairly. I like mine bone-stock, precisely because it's not the holy grail of organic overdrives. I mean, it wasn't meant to be, unless I'm mistaken.

Johnny, if you've already got that Guv'nor clone you built, what's your goal with the DS-1? I suppose if you wanted to turn it into a metal machine, that could be a way to go, but otherwise, why bother?

...Unless of course, you just like to tinker, which I fully understand.

The funny thing is that I visited proguitarshop.com (http://proguitarshop.com/) yesterday and up popped a video demo of the Lovepedal Eternity E6 (http://proguitarshop.com/store/overdrive-pedals-c-6/lovepedal-eternity-e6-p-1385). I listened for a few seconds and thought to myself "self, you can pretty much cop those tones with your stock DS-1." The Lovepedal is literally $200 more.

I welcome disagreement, but I've learned to trust my ears.

All this being said, I use my DS-1 largely in the first 3rd of the rotation of the gain knob. Beyond that, it does get significantly more fizzy than I care for.



Huh huh... Ben said "poo-poo"

11 Gauge
November 5th, 2009, 02:41 PM
This is my problem - I can't find a good list on diodes' clipping thresholds.

It would take longer to review a bunch of data sheets than to simply throw a multimeter on the diodes that you have. You then chain them in series to get the threshold for that half of the signal.

For example, a 1N400X conducts at around 500mV. And a 1N34A conducts at around 350mA. Chain 'em in series and you have ~850mV. That's a near perfect asymm. compliment to go with the stock 1N4148 that's clipping the other half of the waveform.

...Also, most BJT trannies will conduct at around 700mV, when you use either the E & B or C & B as your "diode terminals." The gain and all that other crap are irrelevant - you can literally grab just about any BJT from electronic junk, and most will come up around 700 on the meter when testing diodes.

I kind of enjoy it - I have about a dozen bins with estimated conduction values. I just test them with my Fluke. I don't even care what type they are, as it's fairly irrelevant.

Twang King
November 5th, 2009, 02:46 PM
if you just cut some of the diodes out of it it sounds better

11 Gauge
November 5th, 2009, 02:49 PM
IIn fact, it appears most of the gain nastiness is coming from the opamp.

This is incorrect, and what throws many (most?) modders.

The gain nastiness is a result of being pommeled by Q2, with the stock bias. Cool down that booster stage, and it becomes apparent that the op amp isn't really the problem.

When you get more balanced gains between Q2 (cooling it down) and the op amp (running it a little harder), the combination clipping between the two sound pretty good, and can then be polished with the right clipping diode selections.

If you don't address Q2, it puts the cart before the horse. There's nothing you can do downstream in the circuit to save it, for the most part. and replacing the clippers with LED's just adds insult to injury. 1N400X clippers might help just a bit, but anything with more clamping capability is going to muffle things, and possibly drop you to less than unity gain with the level full up.

11 Gauge
November 5th, 2009, 03:02 PM
I think the DS-1 is poo-poo'd by a lot of folks, and unfairly. I like mine bone-stock, precisely because it's not the holy grail of organic overdrives. I mean, it wasn't meant to be, unless I'm mistaken.

I don't think that it should be. I generally like that it's raw and unrefined. I just prefer a little nip tuck, and try to keep the essence of the stock pedal in tact. Just less treble and a bit more midrange, but keep the bass as is, the heavy compression, etc.

Here is what I think that the DS-1 should sound like (http://machineheadpedals.com/ss_song.mp3) - raw and mean, even slightly unruly at lower gain settings (it's used on all guitar tracks in the clip). The mods in that pedal don't betray the essence of the DS-1, IMO.

If anything, I really like that Brett's first order of business was to try and get his current production MIT's to sound like the old MIJ's, because IMO Boss got it right the first time. Unfortunately, the Toshiba 7 pin op amp is long gone, so the "new kids" just need a touch of love.

It's also interesting to me that no one has attempted to break down the DS-1 circuit for what it really is - an EH LPB-1 boosting into a Rat, with a Big Muff tone circuit. While each of these three components are hotrodded a little bit, that is all that the DS-1 is. But it's ALL in one box, for 40 bucks or less!

The Guv'nor and DS-1 are two quite different animals. The 1st gain stage in the Guv is barely clipping at all (op amp boost), the second gain stage is both boosting and clipping, the LED's just mainly chop off the tips of the higher frequencies, and the added mid control avoids the scoop that the DS-1 has.

If someone could figure a way to bend the DS-1 circuit so that the unused half of the dual op amp could be dropped in place of Q2, then THAT would be interesting. But it would require cutting a LOT of pcb traces and jumpering stuff around...

Ben Harmless
November 5th, 2009, 03:29 PM
The Guv'nor and DS-1 are two quite different animals. The 1st gain stage in the Guv is barely clipping at all (op amp boost), the second gain stage is both boosting and clipping, the LED's just mainly chop off the tips of the higher frequencies, and the added mid control avoids the scoop that the DS-1 has.

Oh, I'm quite aware, I was just speaking pragmatically about Crash's desire to mod a DS-1. IMHO, the Guv'nor is one of the best distortion/od pedals out there for great, crunchy-yet-chewy tones. I wouldn't bother spending my time trying to get those out of a DS-1.

I totally agree though that the DS-1 would be much more usable over a wider range with more mids. I am absolutely not opposed to modding them. In fact, I recently tacked some caps onto a friend's DigiKey order for that very purpose. Of course something is back ordered now...

Faraldi
November 5th, 2009, 03:32 PM
This is incorrect, and what throws many (most?) modders.

The gain nastiness is a result of being pommeled by Q2, with the stock bias. Cool down that booster stage, and it becomes apparent that the op amp isn't really the problem.

When you get more balanced gains between Q2 (cooling it down) and the op amp (running it a little harder), the combination clipping between the two sound pretty good, and can then be polished with the right clipping diode selections.

If you don't address Q2, it puts the cart before the horse. There's nothing you can do downstream in the circuit to save it, for the most part. and replacing the clippers with LED's just adds insult to injury. 1N400X clippers might help just a bit, but anything with more clamping capability is going to muffle things, and possibly drop you to less than unity gain with the level full up.


Hence the pile of dead effects pedals in my home...

:)

Thanks for the clarification 11.

What would you do then to "cool down" that stage? Does it mean replacing Q2?

Thanks,
Joe

11 Gauge
November 5th, 2009, 04:23 PM
What would you do then to "cool down" that stage? Does it mean replacing Q2?

This is the current "solution," and it's what J.C. will be doing to his:

"Reducing Q2 bias (R6 to 150k and R9 to 1k)."

It's as simple as that, and makes Q2 a bit more linear, so that the op amp can work it's magic. But it requires reducing R13 and increasing C8, to recover some gain at the op amp. Actually, "redistribute" is a much better term.

...This in turn means that the clipping diodes usually need the overall threshold increased, which is what we've been throwing around in the zillion posts above. One "side" can probably be left stock, but the other one should be bumped up a tad, to between 700mV - 950mV before the diodes conduct. Probably the easiest way to do this would be to add a BAT42 Schottky diode in series with the other 1N4148. Alternatively, you could add a BAT42 to both of the stock diodes, if you prefer symmetrical clipping.

In a nutshell, the above is the most minimal mod for a DS-1 to nuke the fizz and make it perform a bit better. That's just 3 resistors, 1 capacitor, and a few diodes. After that part is done, it can be fine tuned for the EQ response that you want out of it, if you aren't satisfied with the stock characteristics. Most people want more midrange, it seems.

The "ultimate Q2 fix" will most likely entail replacing the stock BJT with a MOSFET, but it's not a plug and play thing. But MOSFETS have the necessary amount of boost before clipping, so it will be worth the trouble. I'm about to test a proto with a Q2 MOSFET subbed in it, right now.:mrgreen:

11 Gauge
November 5th, 2009, 04:34 PM
IMHO, the Guv'nor is one of the best distortion/od pedals out there for great, crunchy-yet-chewy tones.

I absolutely agree. Also the Bluesbreaker V1 and the Shredmaster, as well.

Marshall got those 3 right on the first whack. Where would M.I. Audio, Analogman, Barber, Visual Sound, Danelectro, and even Xotic be without those three pedals? Let alone all of the other folks who are using them - the Wampler Plextortion is also a tweaked Guv'nor!

I think that the BB V1 smokes the Tubescreamer, and SRV woulda preferred one, given a chance. And the Guv'nor stands toe-to-toe with the Rat. The Shredmaster is so malleable that it's found it's way into some really fancy stomps.

Faraldi
November 5th, 2009, 04:47 PM
This is the current "solution," and it's what J.C. will be doing to his:

"Reducing Q2 bias (R6 to 150k and R9 to 1k)."

It's as simple as that, and makes Q2 a bit more linear, so that the op amp can work it's magic. But it requires reducing R13 and increasing C8, to recover some gain at the op amp. Actually, "redistribute" is a much better term.

...This in turn means that the clipping diodes usually need the overall threshold increased, which is what we've been throwing around in the zillion posts above. One "side" can probably be left stock, but the other one should be bumped up a tad, to between 700mV - 950mV before the diodes conduct. Probably the easiest way to do this would be to add a BAT42 Schottky diode in series with the other 1N4148. Alternatively, you could add a BAT42 to both of the stock diodes, if you prefer symmetrical clipping.

In a nutshell, the above is the most minimal mod for a DS-1 to nuke the fizz and make it perform a bit better. That's just 3 resistors, 1 capacitor, and a few diodes. After that part is done, it can be fine tuned for the EQ response that you want out of it, if you aren't satisfied with the stock characteristics. Most people want more midrange, it seems.

The "ultimate Q2 fix" will most likely entail replacing the stock BJT with a MOSFET, but it's not a plug and play thing. But MOSFETS have the necessary amount of boost before clipping, so it will be worth the trouble. I'm about to test a proto with a Q2 MOSFET subbed in it, right now.:mrgreen:

Very much appreciated.

Tell me this... do you think this small modification would play nicely with perhaps Germanium on D4 and maybe the stock silicone plus a REVERSED Zener in series on D5?

I know enough to be wrong... :) but I know a Zener allows for some current "backflow(??)" so my thinking is (or my hope would be) that it acts like an A/B tube circuit.

Or am I just hitting the crack pipe too hard.

Thanks again!

Joe

PS: PM'ing you

Faraldi
November 5th, 2009, 04:48 PM
I absolutely agree. Also the Bluesbreaker V1 and the Shredmaster, as well.

Marshall got those 3 right on the first whack. Where would M.I. Audio, Analogman, Barber, Visual Sound, Danelectro, and even Xotic be without those three pedals? Let alone all of the other folks who are using them - the Wampler Plextortion is also a tweaked Guv'nor!

I think that the BB V1 smokes the Tubescreamer, and SRV woulda preferred one, given a chance. And the Guv'nor stands toe-to-toe with the Rat. The Shredmaster is so malleable that it's found it's way into some really fancy stomps.

I have a chance to acquire a Guv'Nor for $45. Should I? I never thought of Marshall stomps b4.

11 Gauge
November 5th, 2009, 05:05 PM
Tell me this... do you think this small modification would play nicely with perhaps Germanium on D4 and maybe the stock silicone plus a REVERSED Zener in series on D5?

I know enough to be wrong... :) but I know a Zener allows for some current "backflow(??)" so my thinking is (or my hope would be) that it acts like an A/B tube circuit.

Here is a great web page (http://www.muzique.com/lab/zenmos.htm) on the particulars of Zeners (and MOSFETS) as clippers.

If you can get the asymmetry under control, any "diode" has potential as a clipper, IMO.

11 Gauge
November 5th, 2009, 05:08 PM
I have a chance to acquire a Guv'Nor for $45. Should I? I never thought of Marshall stomps b4.

If it's a V1. The V2 adds some doo doo to the circuit that shouldn't be there, IMO.

for that price, you could get a Dano Daddy-O, which is a V1 clone. I think that subsequent Dano distortions are also Guv clones, but I don't recall which ones.

The GGG Guv kit is only like 60 bucks or so - THAT would be the way to go if you are the DIY type. And I think it's on sale right now.

JohnnyCrash
November 5th, 2009, 07:22 PM
I built a Guvnor from scratch (perfboard in a giant aluminum box)... I agree, if its a version 1 Guvnor - BUY IT. Very versatile. I am going to refine my diode clipping switch since I put in LEDs (as per stock) and can switch select them OR another set clippers. I want to make it a touch more versatile in the non-LEDs I switch in.

To address your comments on R13 Faraldi:
It seems counter-intuitive to lower the resistor value for more gain, but that is what it does. The stock 4.7k is less gain than lower values, like Keeley's 2.7k and others' insanely gained 1k.

The problem is the corner frequency will go up when you lower the resistor value. This means a little less bass.

Stock its either 4.7k with a 1uF which makes for around 30Hz -OR- 4.7k with a 0.47uF which makes for around 72Hz. I want the added gain, but would like to keep the character around 70Hz (seeing how most guitar speakers don't even go much lower than that anyway and in a Dist pedal woof is as much of a concern as fizz).

To address your comments Ben:
I haven't played a DS-1 since the early '90s and I didn't like it. It was too thin fizzy, but had plenty of crunch and rawness. What I hope to do is what I do with JCM800's... redistribute the gain/clipping to reduce fizz... and add some midrange beef. I know to some that top end fizz might be it's charm, but for me it's not :smile:

I found this practically new DS-1 for $15, so I figured "why not?" HAHA!

I think I will not lose much of the main DS-1 character in my few mods, I just want less fizz and more mids... seeing Keeley and 5thumbs options makes mine look like its barely being modded HAHA!

11 Gauge
November 5th, 2009, 07:52 PM
I just want less fizz and more mids...

That would be a PERFECT quote for a modder who wants to charge a small fortune to replace a half dozen components (or less)!

Hah!

Faraldi
November 5th, 2009, 08:09 PM
It's a Guv V2.

He wants $45 for it.

I'd do the DIY that JC mentioned for the $60 or the Daddy-O

I'm just looking for more gain but not Metal Zone gain. I hate scooping. Heck, maybe I just get a DS-1 and start modding from scratch.

11 Gauge
November 6th, 2009, 03:39 PM
OK, then I think I'm probably on this track:

1. Reducing Q2 bias (R6 to 150k and R9 to 1k).

I had two BIG discoveries today while horsing around with a DS-1:

- You can typically get away with just swapping R9 to 100 ohms, leave R6 stock, and it will get Q2 into a pretty good compromise of a bias - lots of sting, gain and bite w/o being overly bright, but having a baseline that's much closer to linear. 220 ohms will drop it down to an almost flat frequency response, but the gain drops significantly. While either one will allow you to keep R6 stock, I REALLY like the swap to 100 ohms for R9.

- I have to recant on the whole op amp thing. I dropped a NJM4559L, and then a NJM072BL into the circuit, and they both sounded like utter garbage - gating, sputtering, terrible stuff at higher gain settings.

...It turns out that BOTH the M5223AL and the NJM3404AL both have an operating supply voltage range of +/-36V - a CRITICAL parameter, it seems. And the 3404 is a dual supply design. The op amp gets punched in the maw so hard by Q2 that it really requires the entire range that these two chips allow, to keep from banging the rails in a really terrible way, especially if you're only supplying the chip with 9VDC.

Sadly, the 3404 is only offered now as a DIP8, but it's CHEAP - 68 cents. Much better than the OPA2134PA, which starts at 2.50! I know that the newest DS-1 has yet another chip in it now, but I thought I'd bring up my findings, since a lot of guys (especially the metal crowd) really dig the long defunct M5223AL, and I think I've figured out why!

JohnnyCrash
November 6th, 2009, 10:53 PM
Finished the mods - video clips coming soon.

So far I noticed one thing. Biasing Q2 colder makes for a lot less crunch at similar settings. This is even with the hotter 2.7k at R13.

TONE CONTROL:
I simply swapped C3 (0.047uF) for C11 (0.022uF). This made C3 tighter (bass) and brighter (mids and highs), while making the Tone control not thin out at higher settings clockwise.

FIZZ:
Reducing the Q2 bias cured some fizz (R6 and R9 to 150k and 1k), but it also drove the pedal less. I accidentally forgot about R13 (4.7k) so I went back and swapped it for a 2.7k. After puting in the 2.7k it helped slightly, but still has noticeably less crunch.

CLIPPERS:
To impress my girlfriend (HAHA), I put in a 3mm red LED on a switch like Keeley's "Seeing Eye mod." Its actually kinda cool. Fades out when clipping less. The switch goes from stock clippers to one clipper being stock and the other being the red LED (assymetrical). The clipping is subtlely different and I'm not sure which I prefer just yet.

So that's all I did:
R6, R9, R13, C3, C11, clipping select switch.

Its a little darker (less fizzy and thin), it has less full-on crunch (but a much nicer crunch!), and the Tone control is more useful. In fact, if the pedal is a shade too dark now, I can turn up the Tone knob without things getting thinned out like it did before!

It's like a "poor man's DS-1 mod." Only 3 or 4 resistors, a switch, and an LED. The caps I simply swapped C3's for C11's and vice versa.

11 Gauge
November 6th, 2009, 11:44 PM
Reducing the Q2 bias cured some fizz (R6 and R9 to 150k and 1k), but it also drove the pedal less. I accidentally forgot about R13 (4.7k) so I went back and swapped it for a 2.7k. After puting in the 2.7k it helped slightly, but still has noticeably less crunch.

If you don't mind fiddling with it a bit more, try reverting R6 to the stock 100K, but change R9 to 220 ohms. If it still needs just a touch more push, drop R9 to 100 ohms.

I now forsee a monogamous relationship with me and the R9 swap to 100 ohms. All these years of building Big Muffs, and it's boost stage is exactly that (10K/470K/100K/100 ohms).

And with the R9 mod only, I'm able to drive my DS-1 reasonably hard, and I'm using a 3.3K for R13. My diode arrangement is around 1100mV for each "side." I think that I'm going to drop one side to about 800mV, and it should be a done deal.

...Then I'll have to finish up my other DS-1 guinea pig, and resist the temptation to get any more.:twisted:

JohnnyCrash
November 7th, 2009, 04:38 AM
If you don't mind fiddling with it a bit more, try reverting R6 to the stock 100K, but change R9 to 220 ohms. If it still needs just a touch more push, drop R9 to 100 ohms.



I don't mind at all. In fact, all night I was thinking my DS-1 needs just a little more push.

As it is now, it is not very DS-1. It's sorta neutered and not as hardcore. The fizz is less and the mids are better, but the crunch and drive are severely lower. A slight tweek towards more crunch and I think I'll find a happy medium between drive and fizz.



I now forsee a monogamous relationship with me and the R9 swap to 100 ohms. All these years of building Big Muffs, and it's boost stage is exactly that (10K/470K/100K/100 ohms).

And with the R9 mod only, I'm able to drive my DS-1 reasonably hard, and I'm using a 3.3K for R13. My diode arrangement is around 1100mV for each "side." I think that I'm going to drop one side to about 800mV, and it should be a done deal.

...Then I'll have to finish up my other DS-1 guinea pig, and resist the temptation to get any more.:twisted:



I don't have the caps to go lower than 2.7k on R13 and keep bottom end, so I'll simply play with Q2 again. I was thinking of leaving the 150k as-is and going with a 500 ohm (I figured it was sort of between the stock 22 ohm and the new 1k), but if you think 100k/220 ohm is good, maybe I'll start there and work my way up or down.

It seems curing the fizz at Q2 also changes how much crunch, drive, and harmonics you get. Its more like an organic overdrive and less like an extreme distortion.

The clippers seem OK enough to keep for now. Stock it seems hard, tight, and crunchy. With the switch in the other mode - an LED on one side and the stock diode on the other, it seems a little more 2 dimensional and breathy. For me to get their flavor I have to play it at low, medium, and high Dist settings... its subtle, but different enough to notice with time. Note decay seems another area where the differences can be heard a little more.

11 Gauge
November 7th, 2009, 08:48 AM
I don't have the caps to go lower than 2.7k on R13 and keep bottom end, so I'll simply play with Q2 again. I was thinking of leaving the 150k as-is and going with a 500 ohm (I figured it was sort of between the stock 22 ohm and the new 1k), but if you think 100k/220 ohm is good, maybe I'll start there and work my way up or down.

If you keep R6 at 150K, then 470 to 680 ohms is probably the most optimal range of choices for R9. I just don't think that you'll get back sufficient drive to un-neuter the pedal to your tastes.

100K/220 ohms are the values for the Huevos Grande mod. It makes Q2 have a basically flat freq response. Gain is pretty good, but I find myself pushing the Dist knob just a bit higher than I would like.

100K/100 ohms really seems to bring the balls back, but drop just enough treble to balance things sufficiently (IMO). And your diodes are not that far off from mine - yours s/b approx 600mV/1600mV (w/the LED), while mine are 1100/1100.

If you need just a bit more punch than 100 ohms provides, 47 ohms may be your perfect value. Luckily it's only R9 that you have to play with.

pchilson
November 7th, 2009, 11:47 AM
11 Guage,

Can you build a list of mods to your liking?

This thread is great but the mods are getting rather "distributed".

JCSIFU
November 7th, 2009, 12:31 PM
...The MOST CLEVER thing that I've witnessed done with Q2 is to replace it with a MOSFET, which basically converts it into a SHO boost. There's a guy who goes by cctsim on a few other boards who seems to have mastered this. Do some googling, and his techniques should pop up.


I want to do cctsim's DS-1 SHO173 MOSFET MOD and I'm not sure which pins go when using the BS170 MOSFET substitution at Q2. Is it that D = C, G = B, and S = E? I have been trying to search for the answer, but I am not familiar with MOSFETS and all the datasheets just list pin outs and not functions. Any help is greatly appreciated.

JohnnyCrash
November 7th, 2009, 12:54 PM
100K/100 ohms really seems to bring the balls back, but drop just enough treble to balance things sufficiently (IMO). And your diodes are not that far off from mine - yours s/b approx 600mV/1600mV (w/the LED), while mine are 1100/1100.



This is what I'll be doing in 10 minutes.

As far as my clippers, they're actually closer to 600mV and 1000mV (D4 is a 1N4148 and D5 is an LED --or-- I flip the switch to go back stock stock two 1N4148's).

I did NOT do the real "Seeing Eye Mod" (which adds the LED in-series) since I wanted assymetrical, but still a bit more clipping.

11 Gauge
November 7th, 2009, 04:14 PM
I want to do cctsim's DS-1 SHO173 MOSFET MOD and I'm not sure which pins go when using the BS170 MOSFET substitution at Q2. Is it that D = C, G = B, and S = E? I have been trying to search for the answer, but I am not familiar with MOSFETS and all the datasheets just list pin outs and not functions. Any help is greatly appreciated.

It appears that cctsim has already at least fundamentally answered your question:

http://www.bossarea.com/forum/forum.asp?FORUM_ID=10

...with his last response.

I'll paste it here:

"This is a mod I did for me and a few friends. It replaces the the CE stage of the DS-1 with a ZVEX SHO MOSFET booster. I posted the mod originally on freestompboxes.org.

The mapping of the electrodes is as follows:

C -> D
B -> G
E -> S

(so you've guessed correctly)

However, check the datasheet from the manufacturer of your BS170 device for the order of the electrodes. Some bending might be required."


Every BS170 that I've used has the same DGS pinout. Download a datasheet and it will give you a little illustration of which pin is which.

I've actually been using 2N7000's myself - they are a little crisper and more raw, and seem to work better in pedals like the DS-1. Their pinout is the same as the 170, but it's inverted to SGD, so you just flip it around 180°.

The big issue with the stock BJT transistor in the DS-1 is that it does NOT have the standard CBE order. I believe that it is CEB (the C and B locations are clearly labeled on the underside of the pcb).

...This basically means that the center pin of the MOSFET must go into the appropriate outer hole in the pcb. In essence, two pins will be "crossing over," so you must be sure that they don't touch each other.

The easiest thing to do would be to replace the stock transistor with part of a chip socket, and then fiddle around with getting the MOSFET leads in the right holes, until you've got it right. Once you've got it working, dab a little hot glue on it to hold it fast.

11 Gauge
November 7th, 2009, 04:17 PM
Can you build a list of mods to your liking?

Do you mean complete mods that I like?

Or specific parts of the circuit and how I like them modified?

I can comment on one or both, and elaborate with my subjective thoughts on what I like about them.

franchelB
November 7th, 2009, 04:39 PM
I have a friend that modded my DS-1. I believed he used Wampler's version. And it sounds great!

pchilson
November 7th, 2009, 05:53 PM
Do you mean complete mods that I like?

Or specific parts of the circuit and how I like them modified?

I can comment on one or both, and elaborate with my subjective thoughts on what I like about them.

Well, kind of on the order of what Wampler did here (http://www.premierguitar.com/Magazine/Issue/2008/Feb/Boss_DS_1_Mods.aspx). But substituting values of how you would mod it.

Just something a bit eaiser to see what and why.

11 Gauge
November 7th, 2009, 07:48 PM
But substituting values of how you would mod it.

Just something a bit eaiser to see what and why.

Gotcha. Since I don't mod the DS-1 to sound like any particular amp, I'll just give a blow-by-blow on component tweaks that I like, and how they affect the sound.

C3 - Reduce to .027uF or .033uF, possibly .039uF. This cap is your "true" input cap, since C1 and C2 are actually couplers for the buffered bypass circuit, which only passes unity gain. By pinching down C3, things typically get much tighter and punchier, and the midrange tends to get accentuated in a nice way.

R9 - Enlarge to 100 ohms or 220 ohms. This will bias Q2 into more of a linear range with a flatter frequency response, smoothing out the highs. A very dramatic difference. Q2 is the first gain stage in the DS-1. Many folks are not aware of that!

C7 - Enlarge to 220pF. Shaves off a little more brightness, allows the op amp to behave just a bit more.

R13 - Reduce to compensate for gain lost at Q2, if tweaking R9. If R9 is 100 ohms, I prefer 2.7K to 3.3K in this slot. If R9 is 220 ohms, I prefer 1.2K to 1.5K in this spot.

C8 - Must be changed to keep the high pass filter the same IF R13 is altered. For 1.2K, it should become 2.2uF. For 2.7K, it should become 1uF. The EXACT high pass frequency is not critical. For instance, you could use a pair of 1uF caps in parallel w/the 1.2K value for R13, and you won't notice a difference. C8 MUST be a good quality cap if more gain is added to the op amp. While I don't like poo pooing mojo components, I speak from experience regarding C8 swaps. Anything polarized is a huge no-no, and I don't even like nonpolarized electrolytics in this slot, either. The best film cap that you can fit in that spot should be used. I prefer metal films, but mainly because they fit easily.

R14 - Often overlooked, this resistor actually alters the clipping behavior of D4 and D5. Increasing it will exaggerate the effect, while decreasing it will lessen it. I actually tend to leave it stock, but it is a valid component for tweaking what happens with the diodes.

D4, D5 - This is very subjective. Personally, I don't like how much the stock diodes compress and limit, but not by much. And I don't care for anything as severe as LED's either - too much compression is lost. I basically chain different diodes in series to get roughly 700mV for one "side," and 900mV for the other (these are values that the diodes conduct at). It isn't so much a matter of asymmetrical clipping as it just seems to create the best "balance."

C11 - Cut down this cap to .015uF to get a similar upper midrange response like a Rat. I don't do it much any more, but it's got a lot of appeal.

C12 - Cut down this cap to make the tonal balance a little less boomy. My favorite is .068uF, but .047uF to .082uF will all reduce the stock bass at the tone control by different amounts. IIRC, reducing it to .056uF will give the pedal the same bass response as a Big Muff (low pass filter frequency of ~400 Hz).

R17 - Increase this resistor to anwhere from 12K up to 18K, but LEAVE C11 STOCK if you do. This will make the treble response much less overt at the tone control. Translation: you can really crank it clockwise and it won't sound too bright. It really works great with single coils.

C14 - Replace with either a nonpolarized cap (electrolytics are okay here), or increase to 10uF if sticking with a polarized E. While the effect is subtle, it is noticeable. For some reason, the crummy ESR of a polarized cap on the output can make it sound a little hinky - the frequency response can be nonlinear, and you want a fairly flat response here. Not a deal breaker, but just a little icing on the cake.

Components that I think can be left as is:

- C1
- C2
- C4
- C5 (in most instances)
- R39 (NEVER alter this)
- C9
- C10 (I actually remove it sometimes)
- C13

If you're convinced that metal film caps sound better, any value from .22uF up to 1uF for C2 and C9 are fine. I typically go with whatever cap fits best, which usually means the smaller value.

C1 and C13 have more to do with the bypassed signal. If you don't like your bypassed tone, try replacing them. I rarely bother.

C5 can be bumped up if you're dropping down C3 significantly (I sometimes go as low as .01uF for C3).

Anyone who decreases R39 doesn't know what they are doing (IMO), and should give their pedal to me, or get rid of it. Boss carefully chose this value as the optimal "stopper" for the op amp. And they also were kind enough to add D8 as protection against voltage spikes on the op amp's input.

Folks get all goofy about tweaking C10, and I just don't see the fuss. If you tweak the gainstaging and diodes properly, you can actually lose C10 altogether. Why? The tone circuit immediately follows. By tweaking that, you don't cut down the highs until you have to. And they can be much more dynamic. Actually, the stock value is typically fine in most circumstances.

That's my basic thoughts on the circuit as a whole, and how each component that I tweak will alter it in a given direction. I don't like referring to my tweaks as something like "the vintage stack mod," or the "cranked tweed bassman mod," because the DS-1's circuit is too crude to truly allow for such. If you think that you're hearing an actual amp sound coming from the pedal, it's because you have a good amp that is filling in the blanks, IMO. Or your hearing is very forgiving.:lol:

pchilson
November 7th, 2009, 08:05 PM
Wow!
Fantastic 11 Guage.
Saved and printed.
Thanks

pchilson
November 12th, 2009, 11:07 AM
I bought a new DS-1 last weekend. This one actually sounds pretty good compared to the first one I had which was new a year ago. Most likely just me that thinks this new one sounds better but who knows there could be differences. Same amp different guitars...

I'm gonna stop by the electronics shop today and grab up a bunch of caps/resistors/diodes/leds so I'll have stuff on hand to use. Taking 11 Gauges list with me...

11 Gauge
November 12th, 2009, 02:06 PM
Taking 11 Gauges list with me...

Some of the values of components on "the list" may not be stocked at your local store. It's more the given range that's important, as opposed to the stock value.

And you can always add caps in parallel to get a sum equivalent of what you want, i.e. .01uF + .0047uF = .015uF. Or .022uF + .0047uF = .027uF.

And resistors in series give you the sum equivalent. So if you want 1.2K, 1K + 220 ohm = 1.2K.

And resistors in parallel provide a fraction of the resistance. For instance, 33K and 22K in parallel will give you ~13.2K.

The only critical material composition is for C8, which might pose a problem. Either they may not have a film type cap in a large enough value, or it might be too big. They will probably have electrolytics, tantalums, and possibly even monolithic ceramics in large sizes, but I'd advise against using them. But if you want to experiment, knock yourself out. It's certainly not that expensive to try. This is really only an issue if you reduce R13, IMO.

Tell us how it works out!

CA_Dan
November 12th, 2009, 02:21 PM
I'm in the process of performing the Mondo-MIJ modification to my DS-1 (also picked up for $15!). I'll post before and after sounds, but based on the link 11-gauge posted it should sound great.

pchilson
November 12th, 2009, 10:17 PM
Well I picked up a bunch of parts today. I seem to have picked a 22pf for C7 instead of a 220pf. I can get that next week when I'll be down there again.

As you run down these changes are they more or less to be done as a whole or are each of them mutually exclusive?

Can I pick and choose (not that I'd know why, just going by description) or is there a rhyme and reason to hitting them all?

11 Gauge
November 12th, 2009, 11:31 PM
As you run down these changes are they more or less to be done as a whole or are each of them mutually exclusive?

Can I pick and choose (not that I'd know why, just going by description) or is there a rhyme and reason to hitting them all?

There is no need to hit them all - I actually advise against it. It's a real PITA to have to backtrack and undo a bunch of tweaks if/when you realize that you probably have gone overboard.

I basically start with these changes with almost any DS-1 mod, and work my way from there:

C3 - reduce (to approx. .027uF - .033uF) to tighten things up, regardless of other mods.

C7 - enlarge to 220pF to smooth out the op amp a bit.

D4, D5 - change, to increase clipping threshold slightly - the stock silicons conduct at around 550mV - I like to push them up to 700mV to about 900mV, with around 1100mV being the upper limit. You could actually leave one stock and just push up the other "side."

...and either increase C12 (to approximately .068uF) OR increase R17 (to 12K-18K), especially if you have bright pickups, single coils, etc.

Everything else are just personal touches, or things that you might want to do to push either the EQ or gain in a certain direction, maybe with the exception of rebiasing Q2, to reduce the excessive treble, but this requires pushing the op amp harder via the R13/C8 tweaks in most cases.

So I'd start with those (in the order listed), and test with each one that you change. Don't be afraid to stop part way through. You can always continue with more mods if you change your mind later on.

pchilson
November 12th, 2009, 11:35 PM
Thanks,
I'll grab a 220pf tomorrow and see about it this weekend.

JohnnyCrash
November 13th, 2009, 07:34 PM
Its best to try the pedal with all of your guitars and amps to see what you don't like - and then go from there.

The major issue with DS-1's is the fuzz factor - I hadn't heard one in years, but remembered I didn't like it for reasons I'd forgotten. I found one for cheap and after hearing what you guys said of DS-1's as well as other's reviews I had a sketch of its problems, limitations and good characteristics.

From there I only decided what to do after finally getting the pedal and playing it through a lot of my gear (about a dozen amps and nearly as many guitars).

While it sounded great through my modified plexi 50 (I built it with ridiculously more mids and bottom), it didn't sound as good with some guitars and amps. I tracked it down to fizz. I also wanted more thickness from the midrange.

Reducing fizz and increasing mids was what I wanted in my opinion, with my gear, BUT for others (especially metal heads) the pedal is great as-is. From there I experimented with at least four incarnations of mods before deciding on the final tweaks.

In my opinion and with my 2 or 3 days of modding, it seems the Q2 tranny is the main heart of the DS-1 sound. It needs to be biased close to what it is stock for it to get really crunchy and have all of those harmonics - but it also can get thin and fizzy due to this. Slightly balancing the fizz factor from there was easy with 11 Gauge and 5thumbs easy to understand technical break down.

Figure out what's "broke" before you decide on how to fix it. It'll save you a lot of time... I lost two full days experimenting on something that shoulda took me 30 minutes.

czech-one-2
November 14th, 2009, 06:15 PM
So, did anybody try that bs170 mosfet/SHO mod? I'd like to here some feedback on the mod before I heat up the iron yet again and subject my DS-1to another round of torment.:lol:

11 Gauge
November 14th, 2009, 09:55 PM
Unfortunately, they're a little more (on sale for $39.99).

For some reason, MF is STILL listing them at that price. I just got a catalog for Music123, and lo and behold:

---The DS-1 brand new, for 29.95--- (http://www.music123.com/Boss-DS-1-Distortion-Pedal-151258-i1124466.Music123)

I've been told that MF, M123, SMD, ZZounds, etc. are all basically the same thing with different names, but only M123 is listing that 29.95 sale price.

Just wanted to pass this on again for anyone who prefers to chop up a new unit instead of a road rashy one from eBay or CL...

JCSIFU
November 15th, 2009, 03:12 PM
So, did anybody try that bs170 mosfet/SHO mod? I'd like to here some feedback on the mod before I heat up the iron yet again and subject my DS-1to another round of torment.:lol:

I did. It is a nice mod, although the bass to me is very loose and farty but that could be because I'm playing through a vibroverb (15" speaker). I dropped the value of C5 to .15 and it helped a little. I am going to put a 2N7000 in next and try it. I can hear every note even at full gain and it has a nice bite to it as well. It's a keeper, but for me I will try to fix the mud I hear when palm muting a low note...like when playing a boogie on the low e and a strings.

czech-one-2
November 15th, 2009, 07:16 PM
I just want to say one thing to .011. Ive been going through your suggestions one at a time over the last few days,and have finally got my DS-1 sounding pretty much exactly where I want it. I've modded dozens and dozens of pedals,always just blindly following some forum suggestion or mod book,but not really having a grasp on what each component is altering and why.Your descriptions are right on and easily understandable,with no air of arrogance or Technical elitism.
I'd love to see you write a book on the topic of modding or building pedals.
Thanks for your time on this forum,its much appreciated by us
guitar players who dont have a Masters Degree in electronics.
BK

pchilson
November 15th, 2009, 07:18 PM
I just want to say one thing to .011. Ive been going through your suggestions one at a time,and have finally got my DS-1 sounding just where I want it. I've modded dozens and dozens of pedals,always just blindly following some forum suggestion or mod book,but not really having a grasp on what each component is altering and why.Your descriptions are right on and easily understandable,with no air of arrogance or Technical elitism.
I'd love to see you write a book on the topic of modding or building pedals.
Thanks for your time on this forum,its much appreciated by us
guitar players who dont have a degree in electronics.
BK

+1000

Much appreciated by us laymen. JC as well. Thanks for these threads.

czech-one-2
November 15th, 2009, 07:22 PM
Ditto JC !

11 Gauge
November 16th, 2009, 08:57 AM
Your descriptions are right on and easily understandable,with no air of arrogance or Technical elitism.
I'd love to see you write a book on the topic of modding or building pedals.

Aww shucks...thanks!

No arrogance? I sure try to avoid that whenever possible. I hope to never fall off the pedestal you've so kindly put me on! I do try hard to keep out the alchemy and B.S. as much as humanly possible.

I've got stuff in the works, but can't discuss it here, for obvious reasons. I'm hoping that what I do share here will suffice for our communal purposes.

I just try my best to keep it fun and simple, with the emphasis on experimenting and learning.

And YES - huge kudos are in order for Mr. Crash. What he's willing to try (and repeat, again and again) and what he gets done in a super short period of time are an immense contribution!

czech-one-2
November 16th, 2009, 12:42 PM
By the way, Heres what I settled on in my MIT pedal-

Diodes- one 914/one 1N4148 ........why? it sounds great!
C1/C13 .047 metal film
C2 - 1uf metal film
C3 -.01 metal film
C7- 220pf
C8 - metal film 1uf
C10 .047 film
C12 .047 metal film
C14- 10uf electro
R14- 10k carbon comp [mojo factor :lol:]
[actually,I've got a ton of them from 808 mods!]
R35- 1k + a brighter blue led

Thats it,thats all it needed,and some of these were just quality upgrades with the same values.I've done almost all of the wampler mods and both keeley mods,this one just sounds ........right:!:
I tried the R9/R13 mod again and still didnt care for it,to me it takes away some of the attitude and rawness of the DS-1.But I really liked the sound of mine stock,which may be the determining factor with how far to go on these mods.
My DS-1 has the Rohm BA728N chip which some have said to be second only to the MIJ TA7136AP chip,which may be why it didnt need/like the R9/R13 mod.But again,I'm just going off something somebody said in a forum.:roll:


.011- Brians book has been indespensible to me,and really taught me how to go about tweaking these things. But what the book lacks is a thorough description of WHY your changing a component,such as your
DS-1 tutorial. I feel like He just didnt have time to go into it,so he felt just giving the specs is enough.I must have gone through my SD-2 three times with his suggestions,never really knowing what the hell I'm actually accomplishing with each component change,just trying to use my ears.Thats no way to go about messing with your favorite pedal!

Thanks again you guys!:grin:

ChipOnly
November 16th, 2009, 03:30 PM
Just a heads-up for anyone interested, music123.com is currently offering free shipping, I think it only last another couple days. Anyhow, you can pick up a ds-1 for $29.99 shipped....

JohnnyCrash
November 17th, 2009, 01:56 PM
I just want to say one thing to .011. Ive been going through your suggestions one at a time over the last few days,and have finally got my DS-1 sounding pretty much exactly where I want it. I've modded dozens and dozens of pedals,always just blindly following some forum suggestion or mod book,but not really having a grasp on what each component is altering and why.Your descriptions are right on and easily understandable,with no air of arrogance or Technical elitism.
I'd love to see you write a book on the topic of modding or building pedals.
Thanks for your time on this forum,its much appreciated by us
guitar players who dont have a Masters Degree in electronics.
BK



+1

11 Gauge has helped me so many times, and without any snobbery. In my excitement to mod this cheap pedal I completely forgot to thank him.

Thanks 11 Gauge!

czech-one-2
November 17th, 2009, 04:03 PM
Wow, I'm really digging the modded DS-1.Perfect all around heavy overdrive/distortion with a great solo tone and just the right amount of compression without going overboard.[some compression is essential IMHO when using solid state amplification.]
The mods seemed to improve clarity,note seperation and increase midrange a bit.The low end is noticeably tighter too.The tone control is useable in a much greater range,and the ice pick is gone,as is the fizzy high end.
My vintage MXR dist + is off the pedalboard and on to a new owner.

Funny .011,you mentioned NEVER change r39 cause two of my previous attempts had different values here.One was even called the 'ultimate DS-1 mod'.:roll: