Brown Sound mods?

[mhartington]

So heres the deal,  I built a BSIAB II and am kinda satisfied with it. But i want to mod it a bit, adding more gain and changing the tone. I want it to sound a little bit more modern rock/metal that 80's rock. Any suggestions?

[KrazyKarl]

Contour knob found on the ggg schematic will let you scoop it a bit more. Also, you might try swapping out the 2N5457s for J201s. I haven't tried this, but I know that the 5457s are warmer sounding because I've swapped some of the J201s out for 5457s. But if you're going more for metal, try the J201s in all positions. You should socket the transistors though to make it easier to swap them without having to solder them all the time.

[paulyy]

I have the GGG kit whitch is nice but I thought it could use alittle more gain myself. I added the contour knob and thats nice to have. R15 on the GGG schematic, I put a 5K linear pot whitch acts as a boost then as you start to turn it up it will add some gain. You may have to rebias the pedal when doing this mod. I replaced C2 with a ON/OFF/ON switch going from a stock 683 cap to a 563 cap. When the switch is Off. It turns it to a Overdrive. The last mod I did was kind of odd. I replaced R10 with a ON/ON switch going from 120 ohms metal film resister (Stock) and 120 ohm carbon film resister. The carbon film seems to add a boost to the whole pedal and gain. works great when its switched to overdrive. I posted a topic on this about the 2 resisters just the other day. Kind of weierd but it works. Heres some pics. Hope they show.

[mhartington]

i swaped out the jfets for all J201s and its ok, kinda too bright and harsh.  the tone i want is similar to the guitar in Motorheads song THe Game. as far as adding the 5k pot to r15, i felt like all it was and external bias control. Any ideas for getting that tone?


heres the link

http://www.youtube.com/watch?v=F_JF8oSxXtM

maybe just a little bit more treble in it

[WGTP]

http://www.aronnelson.com/gallery/main.php/v/WGTP/Sweet16.gif.html?g2_imageViewsIndex=1   

[KrazyKarl]

i swaped out the jfets for all J201s and its ok, kinda too bright and harsh.  the tone i want is similar to the guitar in Motorheads song THe Game. as far as adding the 5k pot to r15, i felt like all it was and external bias control. Any ideas for getting that tone?


heres the link

http://www.youtube.com/watch?v=F_JF8oSxXtM

maybe just a little bit more treble in it

I had a feeling it might be harsh with those trannies. With the stock trannies, another thing you could try is changing the tone stack. Swapping C10 for a 0.047uF, (I think it's 0.047, check out some of the other brown sound mod threads to verify.) Changes the response, may allow you to adjust the tone knob a bit higher, without it becoming unusable, to get a bit more brightness. Contour knob will let you scoop it out more. There's tons of things you can do to the tonestack to change the sound. Check out some of the other threads out there. There's a great one that Mojotron has with a bunch of cool mods. Another one about the AMZ presence control contour mod on the bsiab.

[stringsthings]

I have the GGG kit whitch is nice but I thought it could use alittle more gain myself. I added the contour knob and thats nice to have. R15 on the GGG schematic, I put a 5K linear pot whitch acts as a boost then as you start to turn it up it will add some gain. You may have to rebias the pedal when doing this mod. I replaced C2 with a ON/OFF/ON switch going from a stock 683 cap to a 563 cap. When the switch is Off. It turns it to a Overdrive. The last mod I did was kind of odd. I replaced R10 with a ON/ON switch going from 120 ohms metal film resister (Stock) and 120 ohm carbon film resister. The carbon film seems to add a boost to the whole pedal and gain. works great when its switched to overdrive. I posted a topic on this about the 2 resisters just the other day. Kind of weierd but it works.....

modding is fun, init? .... that is weird that your carbon film/metal film resistor swap produces a different tone .....  nice job on the paint job ! .....

[mhartington]

that link to the Doug Hammond Sweet thing or sweet 16, what is it. I've looked it up and i cant get a straight answer if its a boost or a distortion. anyone want to clarify?

[WGTP]

It is one of the early dual mu-amp distortions that predates the BSIAB.  Notice the similarities and differences by comparing the schematics.  There was a Sweet Thing that was much like the BSIAB and the Sweet 16 that was a 16v (or 2 9v batteries) version both with a different tonestacks.  The Sweet 16 is the Heavy Metalish one, with a nice notch from the tonestack which is not similar to anything else I have seen.  I thought this would provide some ideas for moding the BSIAB I and II, or a slightly different build for those that want something with a little hair to it.   

[mhartington]

Good news, i messed around with the J201s and now everything works fine (one of them was put in socket wrong) and the .047uf if C10 has given me a great tone change.

and now that i was shown it, I'm planing to build the sweet 16 pedal. but i was curious, in the lay out i found, i should a dpdt switch that was 2x3, not a 3x3 like other pedals ive made. where can i get this?

heres the lay out
http://i835.photobucket.com/albums/zz276/mhartington/sthart.jpg

[paulyy]

I have the GGG kit whitch is nice but I thought it could use alittle more gain myself. I added the contour knob and thats nice to have. R15 on the GGG schematic, I put a 5K linear pot whitch acts as a boost then as you start to turn it up it will add some gain. You may have to rebias the pedal when doing this mod. I replaced C2 with a ON/OFF/ON switch going from a stock 683 cap to a 563 cap. When the switch is Off. It turns it to a Overdrive. The last mod I did was kind of odd. I replaced R10 with a ON/ON switch going from 120 ohms metal film resister (Stock) and 120 ohm carbon film resister. The carbon film seems to add a boost to the whole pedal and gain. works great when its switched to overdrive. I posted a topic on this about the 2 resisters just the other day. Kind of weierd but it works.....

modding is fun, init? .... that is weird that your carbon film/metal film resistor swap produces a different tone .....  nice job on the paint job ! .....

Thanks. Its not the best paint job but it works.

[paulyy]

Good news, i messed around with the J201s and now everything works fine (one of them was put in socket wrong) and the .047uf if C10 has given me a great tone change.

and now that i was shown it, I'm planing to build the sweet 16 pedal. but i was curious, in the lay out i found, i should a dpdt switch that was 2x3, not a 3x3 like other pedals ive made. where can i get this?

heres the lay out
http://i835.photobucket.com/albums/zz276/mhartington/sthart.jpg

Glad you got it to work. Good luck with the sweet16 build. Forgot to ask, Is C10 from the GGG schmatics or some where else. Might have to give it a try.

[KrazyKarl]

Glad you got it to work. Good luck with the sweet16 build. Forgot to ask, Is C10 from the GGG schmatics or some where else. Might have to give it a try.

From one of the bsiab mod threads on this site, not the from ggg.

Another mod I liked was changing R14 to 100k and R15 to 4k7. Ed guidry (the guy who designed the bsiab) said he tried this and liked it. It's hard to peg what it does, I think it adds a bit more clarity and changes the grit a tad. He said it had something to do with changing how the transistor was biased (you have to rebias it with the trimpot after making the change). But I tried it and liked it. It may be a good idea to socket it so you can swap them quickly without having to solder so you can test the difference quickly before you forget what it sounded like It's not a huge change, but you may want to try it.