Boss - BD-2 Blues Driver  [schematic]

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modman
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Post by modman »

I couldn't resist getting one off ebay after hearing it in a demo clipof some other pedal. What I heard in the clips sounded so familiar to the ROG Umble.

I'll gladly make a fool of myself saying that for me all tubescreamers and or other basic distortions sound sound lame in comparision to an Umble. Blistering highs, perfect control over the mids, bassy and sweet if you like that. Incredible. I couldn't care less about the question "does it sound like a Dumble amp?" -- this is knock out distortion for me. I've stopped lending it to guitarist friends (wanting just their judgement), they all come back begging me to build them one.

Well, they should buy a Boss Blues Driver -- it's in the same league though noticeably duller and less fliexible tone wise, cf single tone control.

Steve's music center doesn't hesitate to pull Keeley's pants...so it seems. But what I am more suprised about is that there are about 100 caps on board. :shock:
Boss BD-2 Blues Driver Mods

This is not all-inclusive in what can be done to the Blues Driver. It is meant to give an idea of where the tone can be improved or changed. All of the changes are subtle but when packaged together offer a nice improvement.

D3 Change this 1SS133 to a different (1N4002) diode for asymmetrical clipping. This adds second order harmonics. This adds to the tube type sound.

D7 D8 D9 and D10 Change 2 of of these diodes from 1SS133 to a single 1N4002. More second order harmonic distortion. Although the change is slight, it can be perceived. Keeley actually takes out one of the two pairs and replaces it with a single 1N4001.

C1, C7, C6, C12, C13, and C15 Change this electrolytic capacitor to a 10uF tantalum. Tantalum capacitors sound better than electrolytic capacitors. Keeley likes these anywhere there is signal coupling at this high a value. Tantalum capacitors are easy to find in this range.

C14 Increase input coupling capacitor value to 0.1uF for increased bass response from your guitar.

C100 Here is where Keeley can affect the tone control. He prefers a little more lower-midrange and bass frequencies through the tone section. You can increase the lower frequencies by increasing the capacitor value to 0.033uF. Install a switch to add a 0.068uF cap in parallel with this value for the Phat Mode!

Most of the ceramic caps are changed to Expensive Silver Mica (Available through Small Bear Electronics http://www.smallbearelec.com or http://www.mouser.com or http://www.digiley.com). This is what makes the Keeley mod sound so good. A noticeable reduction in noise. An increase in the smoothness and no harshness left. This type of upgrade is not found in anyone's mods. The best sound is right here.

from: http://www.stevesmusiccenter.com/KeeleyBD2.html
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Post by Dirk_Hendrik »

A while ago I was asked wether I was able to do a Monteallums mod on one of these which can pretty much me done from the components list and some common sense alone.

I was. Sounded pretty OK.

Now I do have to compare that tweak against the Indyguitarist mods as Brian spent quite some time on tweaking BD-2's with satisfying results.
Sorry. Plain out of planes.

http://www.dirk-hendrik.com

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Post by modman »

Monteallums... you said it. Just about two years ago he was just selling guitar pots and nut slotting tools that turned out to be drill cleaners when you got them. On his old site you could read he's a guitarist in some religious million dollar circus.

That this seems to have become a household name on TGP shows ... don't know what it shows. It's sickening, you even get a Monteallums sticker with your mod set so that all your friends can see you couldn't afford the keeley mods?
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Post by Dirk_Hendrik »

modman wrote:Monteallums... you said it. Just about two years ago he was just selling guitar pots and nut slotting tools that turned out to be drill cleaners when you got them. On his old site you could read he's a guitarist in some religious million dollar circus.

That this seems to have become a household name on TGP shows ... don't know what it shows. It's sickening, you even get a Monteallums sticker with your mod set so that all your friends can see you couldn't afford the keeley mods?
I know. I know.
But,

If someone asks me to do this and that and I'm able to do so (and do not object for whatever reason) it's just a matter of "you ask, I'll play"
Sorry. Plain out of planes.

http://www.dirk-hendrik.com

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Post by modman »

I found this:
Boss - BD-2 Blues Driver schematic
Boss - BD-2 Blues Driver schematic
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Post by gtrwrks »


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Post by WhiteKeyHole »

Here's a list of mods I did to my Blues Driver to make it the best OD I've heard, no claim to originality, these are just my values:

C100: .033uf
C101: .022uf
C36: .01uF
C35: .047uF
C34: .44uF
C14: .1uF
C17: .01uF
C19: .0047uF
C8: .33uF
C9: Removed

D1: 1N34A
D3: 1N4002

D7: 1N34A
D8: 1N4148
D9: 1N4148
D10: 1N4148
100pF Silver Mica across diodes

Q9: 2N1303 Germanium
Q12: 2N1303 Germanium

R51: 50K pot (under footswitch to adjust mids for different amps)
R34: 4.7K
R26: 3.1K

:x

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Post by Beedoola »

Anyone have mod info from indyguitarist or others? I know Keeley has his listed on his site but I'd like to see some other methods if possible.

Thanks

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Post by puppiesonacid »

what kind of mods are you looking for?

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Post by floris »

I can only post what I have from others (notes and mods), so thank them...

=====================

Where is the clipping stage in the BD-2?
https://www.diystompboxes.com/smfforum/ ... ic=66485.0

http://www.indyguitarist.com/schematics ... 20BD-2.gif

There is a modified fender tone stack consisting of C26, R37, r38, C34, r50, r51, and C35. Download the Duncan's tone stack calculator and play w/ the values to change the frequency response to something you might like a little more.

D7 & D8, D9 & D10, and you can also horse around with D1 & D3.

Stick to D7,D8,D9 and D10 for diode changes. D1 and D3 are NOT clippers. Look for posts from Jay Doyle in the archives for more in the BD2. He wrote a great and lengthy article describing the BD2 in great detail.

I changed mine to 3mm LEDs (D3, D9, D10) and put two 1N4002 at D7, D8... really changed the sound for the best. I was thinking about also putting two LEDs at D7, D8 to remove what's left of the fuzziness. The BD-2 doesn't only use the clipping diodes to create distortion, the IC also does and i suspect some trannies in there does the same. It's really a multi layered distortion.
The stock BD-2 actually sounds pretty bad when you turn up the drive, fizzy, gritty, high pitched fuzziness. Changing the diodes for LEDs got rid of that completely (and changing D3 which isn't in the clipping diodes pattern also made a big difference...) the pedal sounds more like an overdrive but can still go in DS-1 territory when you turn up the drive.
------------------------

... The stock BD-2 actually sounds pretty bad when you turn up the drive, fizzy, gritty, high pitched fuzziness...
Changing the diodes for LEDs got rid of that completely (and changing D3 which isn't in the clipping diodes pattern also made a big difference...) the pedal sounds more like an overdrive but can still go in DS-1 territory when you turn up the drive...
------------------------

https://i279.photobucket.com/albums/kk14 ... layout.gif

=================================

(I know you saw this already but anyway: )

http://www.robertkeeley.com/product.php?id=14
Boss BD-2 Blues Driver Mods - Robert Keeley

This is not all-inclusive in what can be done to the Blues Driver. It is meant to give an idea of where the tone can be improved or changed. All of the changes are subtle but when packaged together offer a nice improvement.

D3 Change this 1SS133 to a different (1N4002) diode for asymmetrical clipping. This adds second order harmonics. This adds to the tube type sound. I like the sound of this change.

D7 D8 D9 and D10 Change 2 of of these diodes from 1SS133 to a single 1N4002. More second order harmonic distortion. Although the change is slight, I like it. We actually take out one of the two pairs and replace it with a single 1N4001.

C1, C7, C6, C12, C13, and C15 Change this electrolytic capacitor to a 10uF Non-polarized caps. Non-polarized caps sound better . I like these anywhere there is signal coupling at this high a value.

C14 Increase input coupling capacitor value to 0.1uF for increased bass response from your guitar.

C100 Here is where we can affect the tone control. I prefer a little more lower-midrange and bass frequencies through the tone section. You can increase the lower frequencies by increasing the capacitor value to 0.033uF. Install a switch to add a 0.068uF cap in parallel with this value for the Phat Mode!

Most of the ceramic caps are changed to Expensive Silver Mica (available through Small Bear Electronics http://www.smallbearelec.com or http://www.mouser.com or http://www.digiley.com). This is what makes our mod sound so good. A noticeable reduction in noise. An increase in the smoothness and no harshness left. This type of upgrade is not found in anyone's mods. The best sound is right here.

Copyright by Robert Keeley 2007
Feel free to distribute or copy to your web page and email me any contributions.

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Post by KHELSTROM »

Anyone have any gut shots or info on the Brent Mason mod from IndyGuitarist for the Boss BD-2 Blues Driver?

Thanks,
-Karl

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Post by modman »

:hmmm: I cannot believe that the Indyguitarist mods are anything more than what is already described above, and was gathered from the internet long time ago. I think... but maybe Brian can comment himself?
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Post by indyguitarist »

modman wrote::hmmm: I cannot believe that the Indyguitarist mods are anything more than what is already described above, and was gathered from the internet long time ago. I think... but maybe Brian can comment himself?
they are actually really easy... I just tweaked a few things for Brent to get it more like he wanted it and came up with a couple of part changes:
c14: .1uf
c17: .01uf
c19: .01uf
tone control cap (c101 I think?): .047uf
d9: led
d10: led
d3: led

on d9 and d10, I connect a .001uf cap across them, so it forms a bit of a low pass filter in that area.

Hope that helps! :)

bw

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Post by KHELSTROM »

Thanks Brian! I did the mod and it sounds awesome! When doing the BM mod do you upgrade to higher quality caps in addition to changing the values you mentioned?

-Karl

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Post by indyguitarist »

KHELSTROM wrote:Thanks Brian! I did the mod and it sounds awesome! When doing the BM mod do you upgrade to higher quality caps in addition to changing the values you mentioned?

-Karl
yes, alot of guys prefer that.... with that said, I don't change anything else on Brent's except for the parts mentioned and I also change c22 to a film cap of the same value. I know, I know... some say it's all mojo but all the a/b tests I've done prove otherwise that EVERYTHING makes a difference... even pcb layout.
bw

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Post by modman »

These mods look very intersting, WKH!
WhiteKeyHole wrote: C36: .01uF
C35: .047uF
But this is the stock value, no?
WhiteKeyHole wrote:C34: .44uF :x
:scratch: Why this value specifically?
WhiteKeyHole wrote:C8: .33uF
C9: Removed :x
You replaced 56nF + 2n2 in series by one 330nF cap?
WhiteKeyHole wrote:Q9: 2N1303 Germanium
Q12: 2N1303 Germanium
R51: 50K pot (under footswitch to adjust mids for different amps)
This is the craziest part of the mod, I can hardly believe it. What gain ranges did these Ge's have? I suppose high gain low leakage would be a first choice? The Mid pot is impressive as well.

Will be trying these!
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Post by modman »

from robertkeeley.com wrote:C100 Here is where we can affect the tone control. I prefer a little more lower-midrange and bass frequencies through the tone section. You can increase the lower frequencies by increasing the capacitor value to 0.033uF. Install a switch to add a 0.068uF cap in parallel with this value for the Phat Mode!

(...)

Feel free to distribute or copy to your web page and email me any contributions. I reserve the right to keep out details of the mod to protect our unique tone change to the pedal. We don't sell parts kits.
Hey, what is he saying here? PLEASE distribute this all around as the Keeley mods because if they are out there nobody will bother to check a Keeley modded Boss for details, and everybody will be doing wrong mods because they are too blinded int he light of the Keeley name that they won't even hear that even adding a 68nF in parallel won't make their pedal sound phat.

680nF is more like it in parallel with the standard cap or not. But 220nF works too and could be enough for me - I mean you do want to hear your sound change when flipping that switch, no?
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Post by floris »

Adding 68nF will lower the cutoff frequency by a factor 3 (33nF compared to 33nF+68nF=101nF). So for instance from 300Hz to 100Hz. That would make a clearly audible change.

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Post by sepulchre »

Man, I can't read all the numbers on the BD-2 schematic. I don't suppose there is a clearer one, is there?
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Post by floris »

Try this one (as was posted above): http://gaussmarkov.net/layouts/bd2/bd2-project.pdf
The component values are clear. The reference numbers are different from the factory schematic.

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