I've designed a Filter Pedal for Bass

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I've designed a Filter Pedal for Bass

Postby FUZZZZzzzz » 10 Jan 2019, 11:41

Hi guys!

It's been a while since I've posted. I just finished a new pedal that I've been working on and decided to share it with you guys. It's a very simple design with only a few parts. If you want to change the sound of the filter you can change the diode and value of the 4,7 nf cap. I prefer both the 2,2 nf and 4,7 nf on a switch. The 1n4148 give the most clean result. The 10k pot tames the filter intensity. You can abandon it completely if you like mayhem. It can create synth like tones (play with the 4,7 nf cap) and even some funky stuff.

The enclosure is tiny. Was a real adventure to make it fit. Enjoy!


Link


Image

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Re: I've designed a Filter Pedal for Bass

Postby Dirk_Hendrik » 10 Jan 2019, 14:35

Thanks.

Do you have this as a schematic as well? I have trouble understanding how the pots are connected. For example, the filter pot goes to the filter connection.. but where does the other side go?
Sorry. Plain out of planes.

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Re: I've designed a Filter Pedal for Bass

Postby FUZZZZzzzz » 10 Jan 2019, 15:03

not yet. will give it a try though.

lug 1 of the 10k pot goes to pin 2 of the 567 and lug 2 goes to pin 5 of the 567. the volumeknop is just a 100k wired like usual, lug 1 to grnd, lug 2 to output and lug 3 to the output signal of the circuit.
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Re: I've designed a Filter Pedal for Bass

Postby FUZZZZzzzz » 16 Jan 2019, 14:24

Someone draw a schematic. Its over at the other place ;)
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Re: I've designed a Filter Pedal for Bass

Postby Optical » 16 Jan 2019, 22:15

Chip datasheet http://www.ti.com/lit/ds/symlink/lm567c.pdf
Cool chip.

What about adding a blend with the input signal?
is the 6v reg necessary or just over voltage protection? what about a zener?
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Re: I've designed a Filter Pedal for Bass

Postby marshmellow » 16 Jan 2019, 22:54

The IC has a maximum voltage of 9V, so with the typical battery or power supply, some sort of protection or regulation is necessary. A zener would work too, sure. If you go with the regulator, add input and output capacitors, otherwise the regulator is in danger of oscillation.

It's interesting how your output is working. From the schematic of the internal circuit of the IC, it is clear that the open collector output would need a pullup resistor for normal operation. Might be something to try. Or maybe this is the source of the distortion in your circuit and it should be left like that.
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Re: I've designed a Filter Pedal for Bass

Postby marcao_cfh » 16 Jan 2019, 23:31

Actually, the LM567 works better with voltages around 5-6V than 9V, at least in guitar effects. It's a kind of "bias" setting.

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Re: I've designed a Filter Pedal for Bass

Postby FUZZZZzzzz » 17 Jan 2019, 10:43

my previous version had in and output caps on the voltage regulator as seen in many of the 780X series datasheets (330nf and 100 nf), but imo theres no difference whatsoever. make sure you use the bigger version and not the 78l06 (those can only go up to 100ma). Im pretty sure you can also use a more common (pedals) 7805. The design is really quiet when not playing. No oscillation whatsoever.
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Re: I've designed a Filter Pedal for Bass

Postby Manfred » 17 Jan 2019, 15:53

FUZZZZzzzz wrote:Someone draw a schematic. Its over at the other place ;)

I drew the schematic according the vero layout.
FilterForBass.JPG
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Re: I've designed a Filter Pedal for Bass

Postby marshmellow » 17 Jan 2019, 17:13

FUZZZZzzzz wrote:my previous version had in and output caps on the voltage regulator as seen in many of the 780X series datasheets (330nf and 100 nf), but imo theres no difference whatsoever. make sure you use the bigger version and not the 78l06 (those can only go up to 100ma). Im pretty sure you can also use a more common (pedals) 7805. The design is really quiet when not playing. No oscillation whatsoever.


The fact that you don't hear it doesn't rule out it's existence. Also, per datasheet of the 567, maximum current draw is 13mA, so the small regulator will do fine.

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Re: I've designed a Filter Pedal for Bass

Postby FUZZZZzzzz » 18 Jan 2019, 10:25

marshmellow wrote:
FUZZZZzzzz wrote:my previous version had in and output caps on the voltage regulator as seen in many of the 780X series datasheets (330nf and 100 nf), but imo theres no difference whatsoever. make sure you use the bigger version and not the 78l06 (those can only go up to 100ma). Im pretty sure you can also use a more common (pedals) 7805. The design is really quiet when not playing. No oscillation whatsoever.


The fact that you don't hear it doesn't rule out it's existence. Also, per datasheet of the 567, maximum current draw is 13mA, so the small regulator will do fine.


Fair enough ;) Thanks for your support! I see the guys at perf and pcb effects layouts also put a 100 uf in the power section. Better safe than sorry I guess

http://effectslayouts.blogspot.com/

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Re: I've designed a Filter Pedal for Bass

Postby snk » 16 Mar 2019, 00:05

Interesting, I'm curious and i may build it :)
Thank you for sharing !


Is there any updated veroboard with diode or regulator and the 100 uf in the power section ?

How would you make the filter effect more "ovbious" (with more resonance, or more cutoff, more "synthy") ? By changing the 4,7 nf cap ?
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