Boss BD-2

[Liam]

Anyone point me in the direction of any sensible DIY mods? Looking for a little bit less fizz.

[turbolx5oh]

I've done several of Monte Allums mods including the BD-2 mod and they all work and sound great.

http://www.monteallums.com/pedal_mods.html

[Liam]

What happened to all the free mods everyone used to share?

I have found some details that might help me do something a bit more "homebrew" - but I think Monte Allum might well be my fallback position.

Thanks for the reply.

Liam

[Mark Hammer]

What happened to all the free mods everyone used to share?

I have found some details that might help me do something a bit more "homebrew" - but I think Monte Allum might well be my fallback position.

Thanks for the reply.

Liam

From Robert Keeley's site at: http://www.robertkeeley.com/product.php?id=14

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. 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 www.smallbearelec.com or www.mouser.com or 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. 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.


Looks pretty free to me.

[Liam]

Thanks Mark!! I'd not noticed that on the bottom of the page - he's definitely one of the good guys, isn't he!

Liam

[Liam]

OK, nearly ready to go with trying some of these mods. Going to start by upgrading all the couplers, then doing the diode mods, then the tone controls.

I'm only going to change the ceramics in the direct signal path to silver mica I think, could get expensive otherwise.

Incredibly complex circuit for what it does. 3 gain stages? 2 clipping stages? 4 tone filter networks? And looks like it was possibly designed to have separate volume controls to give "preamp" style clipping and "power amp" style clipping. Quite tempted to do something with that, seems a shame not to have them independently adjustable.

The bit that interests me the most with this pedal is the way that the distortion or clipping dies rather unnaturally as a note fades. Without that weird quirk it could be the truly "transparent" pedal you read about. It's the best clean boost I've ever tried. Plenty of headroom too.

[Liam]

First jobs done. Changed all the 10 uF coupling caps to non polarised, and went up to 0.1 on C14. If it makes a difference, it's very subtle. Next I changed C26 (220pF) from ceramic to Silver Mica. This puts a subtle and HiFi sounding shimmer in the similar fender/marshall tone circuit. Makes very little difference in the BD-2, probably because the BD-2 is like the fender circuit with the treble control rolled most of the way off.

Next stage will be diode swapping. I'm expecting more drastic results with this...

[Liam]

Diode swapping done now. Swapped D7 and D8 to a single 1N4001 as suggested. Subtle but definite difference, only really when the gain is wound up high.

Next up swapped D3 for a 1N4001 (1N4002 was the suggested diode for the mod). Much nicer, although something is "beating" a little bit on 7th fret G string. Will try this with a loud amp tomorrow, I think it will sound a bit better with a little compression. The notes "die" much more naturally than they did with symetric clipping.

Finally tried a few different values for C100. I like 0.047 uF best, 0.068 is too flabby, and 0.033 doesn't have quite enough bass for a transparent volume boost with the gain rolled off. I certainly don't feel the need for a "Phat" switch.

Going to post about LEDs separately...I'd like blue for a blue pedal!

[Liam]

[QUOTE=Liam;50640]Will try this with a loud amp tomorrow, I think it will sound a bit better with a little compression.[QUOTE]

And it does. Gave it a try with my Marshall BB reissue today.

This pedal has gone from an interesting attempt at a transparent boost/overdrive pedal into something that I can use. Going to have to put it on the pedalboard now, it really is something special. Fizziness is much calmed down, tone control lets through enough bass to match a Telecaster neck pickup. Just need to check it's got enough headroom for a clean boost on humbuckers.

I would not have considered this pedal worthy of live or studio use before the mods. Probably going to use it a lot now...