# Bluesbreaker mod.. help please



## xlDino (Oct 29, 2022)

So I’m planning a build with the Bluesbreaker pcb, been emulating some values in LTSPICE, and also removed the tone knob (I know, silly, but it’s a project for a friend). Here’s what I’m planning and my plans to do it, any input would be highly appreciated.



			https://docs.pedalpcb.com/project/BlueBreaker.pdf
		


C1: 10nf cap swapped to 100nf, pedal seemed to respond better, is this redundant?

R4: 33k swapped for 47k, I miss ordered this one, but 47k sounded good in my emulations, seemed like it added some gain?

Drive pot: 100k swapped for 250k, pretty simple, more gain

R5: 10k swapped for 3.3k

R6: 220k swapped for 330k, more gain

R9: Removed, less clean signal

R8/R9: changed from 1k, 6.8k, to 10k, 10k

One diode removed for asymmetrical  clipping

RC4558 OpAmp

Tone Pot Removed, C6 Removed.

This has been working well in my emulations, I’m planning the tone pot removal on the PCB, it’s my first time and I’m getting a bit confused. What would it look like? If someone could draw it on the pcb for me or explain it, would be greatly appreciated.

(PS, the goal was to take a Bluesbreaker style circuit, hot rod it, and voice it like his OD-1 rev A)


----------



## swyse (Oct 29, 2022)

That's going to be an interesting pedal for sure. What is R9 going to be, 10k or removed? As for the tone control removal, you just need to bridge pads 2 and 3 for the tone control (usually pin1 is the square one), and if you don't populate C6 it doesn't really matter if you know what pad is what and you can bridge all 3 together. Make sure you pop a resistor leg or something to jumper the diode you plan to remove. Also, if you couldn't find an OD-1 PCB and would prefer that route instead aion fx has them.


----------



## Locrian99 (Oct 29, 2022)

swyse said:


> That's going to be an interesting pedal for sure. What is R9 going to be, 10k or removed? As for the tone control removal, you just need to bridge pads 2 and 3 for the tone control (usually pin1 is the square one), and if you don't populate C6 it doesn't really matter if you know what pad is what and you can bridge all 3 together. Make sure you pop a resistor leg or something to jumper the diode you plan to remove. Also, if you couldn't find an OD-1 PCB and would prefer that route instead aion fx has them.


I think he’s got some mislabeled there.   The r9 removal I think he means remove r6 to remove clean signal from coming through and r7 is the 220k to 330k


----------



## xlDino (Oct 29, 2022)

to eliminate the tone pot I just omit C6, Jumper R8, and Jumper the tone pot right?


----------



## xlDino (Oct 29, 2022)

I’ve tweaked the design a bit, the first opamp was feeding way too much gain into the second one, now it’s just a matter of removing the tone on the PCB


----------



## xlDino (Oct 29, 2022)

Will post updated schematic tomorrow


----------



## xlDino (Oct 30, 2022)

https://i.postimg.cc/T3VSrJ7V/3717714-D-9778-4-BA6-86-D4-D3714-AB756-A8.jpg
		


There’s my schematic, don’t mind my scrawl, but this should all work


----------



## cdwillis (Nov 10, 2022)

Did you get this built yet? I feel like it's going to be bright as hell, but I could very easily be wrong


----------



## HamishR (Nov 20, 2022)

Rather than just leaving parts out for the tone pot, I would suggest tacking in say a 12K resistor from pin 1 to pin 2 on the board where the pot would connect, and a 12K resistor from pin 2 to pin 3. That would simulate a tone pot at noon. From there you could adjust to taste.


----------

