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DIY Stompboxes => Building your own stompbox => Topic started by: iainpunk on November 09, 2019, 05:46:08 PM

Title: Behringer SF300 (BOSS FZ2 clone) chainsaw mod?!
Post by: iainpunk on November 09, 2019, 05:46:08 PM
i have gotten the SF300 almost a year ago from my brothers girlfriend.
i really like the sound but there is the problem of the unusable trebble control (at least in my opinion).
when  full boost, it boosts everything above 800Hz with 2.2dB/Oct, and when it full cut, it cuts everything above 175Hz with -3dB/oct.
honestly i prefer it when its in the middle, or just below it, so the trebble response is flat
i was looking at the board and realised that i have  easy access to every point i need to if i want to replace the passive part with a gyrator, or two...

enter the HM2 by boss, its a classic, and i love it, especially with every control cranked, so i thought it was a great idea to put the gyrator circuit on a mod board and replace the cap and resistor with the chainsaw guts (there is a lot of space in the enclosure), and thus combine two worlds, the DOOM/sludge and the DEATH/GRIND worlds...

(https://i.postimg.cc/JGWFZPMq/BOSS-FZ-2-CHAINSAW-MOD.jpg) (https://postimg.cc/JGWFZPMq)

does anyone have objections before i DESTROY PLANET EARTH with this SONIC NUKE??!??, or ehm.... does anyone have suggestions what i can improve upon on my idea before i do something stupidly evil like this??!??

, grts, iain
Title: Re: Behringer SF300 (BOSS FZ2 clone) chainsaw mod?!
Post by: Fancy Lime on November 10, 2019, 05:55:32 AM
Sounds Like a great Idea! Please report back on the result. I've had the same feelings about the FZ-2 treble knob, when I tried it many years ago and stupidly didn't Bus it.

Andy
Title: Re: Behringer SF300 (BOSS FZ2 clone) chainsaw mod?!
Post by: iainpunk on November 10, 2019, 08:48:44 AM
yeah, ill report back when im done and maybe ill ask my brother if i can borrow his recording setup (he is a rapper, he has a vocal booth is his bedroom)

im so exited, cant wait to be soldering again
Title: Re: Behringer SF300 (BOSS FZ2 clone) chainsaw mod?!
Post by: iainpunk on March 12, 2021, 12:25:12 PM
its more brutal because its a Zombie thread now

yeah, ill report back when im done and maybe ill ask my brother if i can borrow his recording setup (he is a rapper, he has a vocal booth is his bedroom)

im so exited, cant wait to be soldering again
well... that took longer than planned, i first modded some diy pedals with the same ''mod board''/''daughter board'' to see if it would work, and it does, so i finally took on this SMD board, of which i was afraid of fuccing it up...

here's a rough step by step process i took:
1) the first thing was soldering the daugher board, just a simple perf-board, 4 resistors, 2 caps and a BC547, all according to the schematic below.
2) i located the treble pot on the solder side of the board
3) followed the trace off of the middle lug, and found the cap and resistor to ground
4) de-solder those
5) solder wires from the mod board output to the middle lug of the treble pot, the ground to a random ground pad, and the VCC to the red battery lead pad.
6) close the pedal and grind away for days

cheers

(https://i.postimg.cc/vgvZzx0k/chainsaw-mod-board.jpg) (https://postimg.cc/vgvZzx0k)