# Everyone Post their pedal mods



## cdayo (Jan 28, 2014)

Everyone post the pedal mods! A video will follow soon!

BOSS DS-1 Bass driver

This is my first attempt at a pedal mod, hence the oddly fitting components and the heat shrink:confusion:. Picked up the DS-1 for 25 bucks. All other parts cost a few dollars. It's been a while since I researched, decided which components to substitute and their affect so i will do my best to recollect.

I made decisions about my mods according to this thread and a few others
http://www.talkbass.com/forum/f36/boss-ds-1-modded-bass-clip-included-461804/

The thread is long and took me a while to decide what worked and what didn't so I will list my mods below. Basically, I took out most of the stock caps in the circuit and replaced them with alternate values or with better quality caps. Most of the electrolytics in the signal chain were removed. I also replaced 1 resistor and removed two diodes (D4, D5)

Before




After --- They look crooked because I had to squeeze them in!


Hard to see what all the numbers are, but compare the two and you can see what got changed. It was a tight fit for some!

Caps (*=upgraded cap, same stock value)
c1-0.1uf
c2-1uf*
c3-0.1uf
c5-0.01uf
c8.22uf ----- this is an important mod to make DS-1 BASS compatible. It raises the clipping floor from 33hz to 154hz. Really keeps the integrity of the bass tone
c9-1uf*
c10-0.022uf (similar to c8, except it filters out the highs)
c11-0.022uf
c12-0.047uf
c13-0.1uf
c14-1uf*
c20-0.047uf
c21-0.047uf

RESISTORS
R17 - 15k 1/4w 
R7 - I read that swapping out this stock value (470k) with a 330k would lower the gain. I tried it out and found it actually made my signal quieter than when the pedal was bypassed so I put the stock 470k back in. I could try a value in between but it doesn't have a drastic affect on tone so for now it's staying stock.

DIODES
I think this is the most interesting aspect of the DS-1 BASS mod. The diodes suggested to tinker with to best affect clipping are D4 and D5. I replaced D5 with an LED re someones advice on a post and found there was too much clipping. In fact, I kept the distortion knob totally zeroed and there was still too much distortion. I played around with some different settings, removed the LED from D5 and tried the pedal with just the stock D4 diode, no D5. It was a marked improvement but I thought it still sounded a little DS-1ey. Following advice of another post I removed D4 and tried it without either D4 or D5 and that was it. It allowed me full range on the distortion knob with sounds as follows. At zero there was almost no dirt at all (like a boost), at noon there is a nice amount of dirt and drive and while maxed, it is about as close to fuzz as I think it can be before it starts sounding like crap. (sometimes I think fuzzes can really sound like crap)
You can see in my picture that both D4 and D5 diodes are left empty, minus two sockets I left in D5 for testing. 

IC CHIP
While I was researching I discovered that the DS-1 uses an inline IC chip, making it incompatible with most classic pedal IC chips which are 4x2. Someone on the basstalk forum suggested an adapter PCB to allow for the use of other ICs. As seen here http://www.monteallums.com/pedal_mods.html#CA If I ever get around to etching, I might do this as one testimonial says it is well worth it with an JCR4558 (or something like that). Otherwise it will stay stock unless someone else can offer up some different advice.


Resources
http://www.premierguitar.com/ext/resources/archives/legacy_files/schematic.pdf

Good DS-1 tone breakdown by Wampler
http://www.premierguitar.com/articles/boss-ds-1-mods-1


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## mhammer (Nov 30, 2007)

Two broad categories of "mods": those that shape the tone in the direction of what the user desires (e.g., EQ, noise, etc.), and those that add functionality (e.g., extending range, adding "tricks").


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## fraser (Feb 24, 2007)

cdayo, looks like you did a lot of work-
nice write up and great idea for a thread.

ive been tweaking crybaby wahs.
its pretty easy stuff, but a lot of fun.
every change you make affects the sound.

the first one i did was a conversion to clyde mccoy parts values.
just resistors and caps, no fooling with inductors or pots.
well pleased with the results of that, i did another one,
matching the values in the old colorsound inductor based wah.

for the placement and schematic, including part names, 
look here-
http://www.geofex.com/article_folders/wahpedl/wahped.htm
specifically the what affects what schematic.

heres how to do it-
first the q resistor, rq- the one parelleling the inductor- its a 33k- yank it out, dont put anything in its place.
rb2, the next resistor from the inductor and rq, its normally 82k- replace that with a 100k.
cbp- the electrolytic cap going from rb2 and ground- swap that for a 10uf
rc2, the resistor feeding the collector of the second transistor- yank it out and replace with a straight jumper wire
the input resistor, rin, normally 68k- replace with a 100k
re1, the resistor coming from the emitter to ground of the first transistor normally 470r, or 330r- replace this with a 1k trimpot
or just a temporary pot so you can dial it in.

this circuit is very bass heavy when re1 is replaced with the jumper found in the original colorsound wah,
so that trimpot can be used to tweak that value, and control the bass. i found it best at around 220r.

lastly, there is a voltage divider at the output-
2 100k resistors-









the 100k lin is the wah pot.
this creates a volume drop- so i did as shown, but replaced the 100k from the 1st lug of the pot with a 100k pot and dialed it in.
i found 68k was just right,
giving just a slight boost above unity.
so i basically have a 100k going to the 3rd lug of the pot- to ground.
then i took the 2 wires that normally go to the output of the wahs switch,
and tacked them to one end of a 68k resistor-
then ran the other lead of the resistor to the switch.

then, i re-indexed the pot, by loosening its nuts and turning it a bit-
then i tweaked the rack setup.

now, im not great at explaining myself.
and i dont have much of an understanding of the whys and whatnots-
but all this info is available on the net.
took me a couple hours one day, and this wah sounds incredible.
i havent played with inductors or pots, and in this case i havent even replaced the caps with better ones.
so far im loving this wah- before that i never used it.
extremely quacky, but much smoother than my mccoy modded one.
the mccoy has that peak in its range that makes it 'vocalize',
but this one is very vocal throughout its whole sweep.

once i upgrade the caps ill take some pics (maybe today)


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## cdayo (Jan 28, 2014)

Post pics! I watched the story behind the cry baby wah last night on youtube so I know a lot about what you are talking about, though I wouldn't have a day ago. 
Any chance you could compare the Mccoy mod to the colour sound? I am going to do a DS-1 comparison video in a few days when I have both pedals at home.


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## fraser (Feb 24, 2007)

soon as i get the chance ill get some pics for sure-
for comparison of wah values,
heres the chart i use
http://www.aronnelson.com/gallery/m...Wah_Comparisons.gif.html?g2_imageViewsIndex=1

theres a lengthy discussion on the making of this chart here-
http://www.diystompboxes.com/smfforum/index.php?topic=52412.0;wap2

the mccoy and colorsound, although pretty close parts wise, sound very different.
the mccoy is instant hendrix- while the colorsound has a much funkier voice.
its the early 70s porno wah.

i guess the best thing would be to go with a bunch of trimpots, and pots/switches to vary the capacitors-
in that way you could get all the different classic voicings in one wah.
itd be easy to do for sure, and there are some like this commercially available.
i need more crybabys to mod, i want to do one like that.
though i fear id never stop fiddling with it.

here are some of my favorite links regarding wahs, 

http://www.geofex.com/article_folders/wahpedl/wahped.htm

http://fuzzcentral.ssguitar.com/mccoy.php

http://fuzzcentral.ssguitar.com/axiswah.php

http://www.wah-wah.co.uk/

http://www.diyguitarist.com/


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## ONFLOOR AUDIO (Jul 22, 2010)

The Five essential mods for the Boss SD1 Super Overdrive !!

Step 1 

Remove C3 cap , and replace it with .1 uf metal film ( or .12uf - .15uf for more low end )
Remove D6 Diode , and install a 1N34A germanium diode ( Warmer , more tube like clipping )
Remove C6 cap , do not jumper , leave it empty ! ( This mod has been said to lift the blanket off the speaker etc etc )
Remove R6 resistor , and replace with 2.2 K ohm ( increases the gain )
Remove JRC4558DD op amp , and replace it with JRC4558D ( note single " D " ) for classic Tube screamer tone !







There is many , many more mods that can be performed to the SD1 , but these will really help this little yellow box become a pretty good Overdrive that can hang with some very expensive OD's costing twice the price , if you confident with a soldering iron , be sure to do these mods ... you will thank me later !


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## mhammer (Nov 30, 2007)

Increasing the value of C3 will add more bass, although how much bass is a function of *both* C3 and R6. Increasing the value of one OR the other will lower the point at which bass is rolled off. Increasing one and reducing the other, as suggested. will result in negligible change.

With R6=4k7 and C3=100nf, rolloff is 339hz (stock is around 720hz). With R6=2k2 and C3=100nf, the rolloff starts around 723hz.

Note that the suggested swapping of one silicon diode to a germanium type will lower the clipping threshold. If one attempts to increase the gain, via R6, then you'll get more clipping, but will have lost a bit of output level. If you rely on the pedal for your sound, fine. If you rely on the joint interaction of the pedal pushing the amp harder, then that might not be what you want.

Note as well that by introducing more bass, you will produce more clipping, even if you don't monkey with the gain, since more signal "lives in the basement". Indeed, the entire purpose of the stock values of R6 and C3 (and their equivalent in the Ibanez TS-9 and Boss OD-1, and their many derivatives) is to maintain a relatively constant degree of clipping across the entire fingerboard by attenuating the bass in the clipping stage.

In any event, the SD-1 has greater gain (max = 221x) than the TS-9 (max = 118x), so attempts to up its gain will tend to turn it from a smooth overdrive into something rather different.

One mod worth pondering is something I did to a TS9 clone I made and sold to Tony D of Monkeyjunk. Instead of D5 (or D6; one's as good as the other), I inserted a pot to vary the series resistance with one of the clippiing diodes. This yields a continuously variable asymmetry/symmetry. When the pot resistance is zero, you have the more compressed traditional TS-9 clipping. As the series resistance is increased, one half wave gets less clipped than the other, and one gets a more dynamic attack.

A second mod to any of these types of overdrives is an amalgam of something one sees in both the Rat and the Timmy. I mentioned above that the gain and rolloff of the clipping stage is a function of both the resistor and cap. It is possible to have *two* such parallel RC networks, such that the gain is different for different parts of the frequency spectrum. In the Rat, a second RC pair cranks the gain for stuff above around 1.5khz. In the Timmy, and workalikes, there can be a variable resistance (pot) in series with a fixed resistor, instead of R6. As that pot resistance is increased, the rolloff point goes downward, although the gain is simultaneously reduced.

Alternatively, one could simply run a 6k8/100nf pair in parallel with the existing 4k7/47nf pair. That would keep the basic character, of the pedal but add a kind of underlayer of a little more bass. More specifically, the 6k8/100nf pair would provide essentially flat response for content down to 234hz. The stock 4k7/47nf pair would provide a max gain of 221x for stuff above 720hz, and the 6k8/100nf pair would provide a max gain of 152x for stuff between 234 and 720hz.

As for the value of seeking out the other op-amp chip, I am on the fence. On the one hand, people do notice tonal differences between various broader categories of op-amps - NE5532 vs TL072 vs LM1458 vs OP275 vs JRC4558. On the other hand, my sense is that once you start monkeying around with the other parameters, especially the diodes, the sort of pseudo-EQing that the chip change provides tends to get lost.

For those who wish to custom tailor their TS/SD style overdrive, I recommend reading both the labnotes on tone controls at the AMZ site, and the Technology of the Tube Screamer at the GEOFEX site. There is clearly value to be gained by tweaking these pedals to your taste. As to whether there is any _definitive _set of mods, I leave that more to the realm of those who make their livelihood marketing such things. Like I say, two categories of "mods": making a pedal have a function or identity it never had before (e.g., turning a phaser into a vibrato effect, sending the wet and dry signals in a delay to separate outs), and tailoring the tone or range of the existing functions more to your needs/liking.

As for caps, I am of the belief that if one is making/tweaking a high-end preamp or other processor for pre-recorded music, or any processor that is taking wide-bandwidth multi-source signal and processing it in as clean a fashion as possible, then cap type can matter very much. If one is destroying a single narrow bandwidth signal (i.e., guitar distortion), and feeding it through speakers that acts as steep lowpass filters, then cap type matters much much less. All components matter more in some contexts than others, whether it be resistors, caps, chips, diodes, trannies, etc.


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## kat_ (Jan 11, 2007)

I don't know if there's anything stock left in my Crybaby. It's an ongoing Frankenstein. I don't even know what I've done to it anymore.
The most obvious mod I did was to compare the red and yellow Fasel inductors. I put both of them in with an On-Off-On toggle switch. When the switch is in the middle (off) position the pedal does volume swells without any wah-ing. I like that a lot.


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## fraser (Feb 24, 2007)

kat_ said:


> I don't know if there's anything stock left in my Crybaby. It's an ongoing Frankenstein. I don't even know what I've done to it anymore.
> The most obvious mod I did was to compare the red and yellow Fasel inductors. I put both of them in with an On-Off-On toggle switch. When the switch is in the middle (off) position the pedal does volume swells without any wah-ing. I like that a lot.


i have a little pocket sized notebook-
im not a big pedal modder, just the crybabys-
but i record the changes/tweaks i make in it.
i wouldnt remember if i didnt write it down.
i really like the idea of putting 2 inductors on a switch-
what is your opinion on those inductors?

i tried something i saw online,
putting a magnet on the wahs inductor.
its cheap and non-permanent fun.
it does sound nice, at low volume-
makes a cleaner, brighter wah sound.
but introduces a ton of microphic feedback.
in fact you can hear the frequency shift as the magnet nears the inductor.
i used those little pill sized neodimium magnets- maybe they are too strong.


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## kat_ (Jan 11, 2007)

fraser said:


> what is your opinion on those inductors?


They are exactly the same. That was the first thing I ever did to this pedal and it was incredibly disappointing. That was about 6 years ago and I've used the pedal with dozens of various guitar and amp combinations and in every single situation the two inductors are exactly the same. 
I keep them though, in the hopes that someday I'll find a difference.


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## fraser (Feb 24, 2007)

kat_ said:


> They are exactly the same. That was the first thing I ever did to this pedal and it was incredibly disappointing. That was about 6 years ago and I've used the pedal with dozens of various guitar and amp combinations and in every single situation the two inductors are exactly the same.
> I keep them though, in the hopes that someday I'll find a difference.


you know what, i read much about wahs recently.
folks all over the net talking about the red vs the yellow dunlop fasels.
like how one is a vintage sound, the other a modern sound.
but it was clear to me how much a couple resistor value changes etc could achieve in that regard.
sorry it was a disappointment in your case,
but i appreciate your input.


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