Author Topic: I've designed a Filter Pedal for Bass  (Read 5000 times)

snk

Re: I've designed a Filter Pedal for Bass
« Reply #60 on: April 27, 2019, 05:15:16 AM »
Hello,
First report :
Also, if you would like to check that the ground wire (middle lug of the voltage regulator) is connected to pin 7 of the 567 chip?
Yes, it is.
I tested with my DMM (middle lug of the voltage regulator to pin 7 of the 567 chip), and it beeps as expected.

After checking continuity,
ROW A : no beep produced by the DMM, as expected => GOOD.
ROW B : It beeps, as expected => GOOD
ROW C : no beep, as expected => GOOD
* ROW D : my DMM screen displays a value around 1030, but it doesn't beep => strange *
ROW E : no beep, as expected => GOOD
ROW F : no beep, as expected => GOOD
ROW G : It beeps, as expected => GOOD
ROW H : It beeps, as expected => GOOD

could you also check for solder bridges between paths.
I didn't noticed anything suspect.

rankot

Re: I've designed a Filter Pedal for Bass
« Reply #61 on: March 24, 2020, 09:33:33 AM »
I've built this at last! Works, but not as intended - Filter pot doesn't change the sound. Or exactly, it does change it when I put sine wave input into pedal and look output at the oscilloscope, but when I play through it, the change is inaudible. I tried with different diodes and capacitor values, but Filter pot behave the same.
50 pedals and counting!

rankot

Re: I've designed a Filter Pedal for Bass
« Reply #62 on: March 24, 2020, 10:17:23 AM »
Hm, I think I found what's the problem - it seems that capacitor across pins 2 and 3 needs to be bigger. I tried with an on-off-on switch with three different values: 1n2, 1n2+1n2 (2n4) and 1n2+3n3 (4n5), but all of them sounded almost the same with my bass, so I tried 1n2+10n and it suddenly started to works as I expected. I will leave this switch so I can test this with a guitar, maybe it will sound good with lower capacitances; if not, I will remove it and leave 10n only. I will certainly report my findings here.
50 pedals and counting!

FUZZZZzzzz

Re: I've designed a Filter Pedal for Bass
« Reply #63 on: March 24, 2020, 11:41:34 AM »
cool! glad you got it working. just build one for a touring friend with 2n2 and 4n7 options. and also between 1n4148 and some germanium on a switch. he likes it a lot on his bass. i dont like it that much on guitar though.
"If I could make noise with anything, I was going to"

rankot

Re: I've designed a Filter Pedal for Bass
« Reply #64 on: March 24, 2020, 03:10:55 PM »
I also have a switch for diode type: LED/1N4148/BAT43, but to me it seems that it affects only the volume a little?
50 pedals and counting!

FUZZZZzzzz

Re: I've designed a Filter Pedal for Bass
« Reply #65 on: March 24, 2020, 03:37:00 PM »
i found that 1n4148 is the most stable sound for funky stuff, but germanium diodes can be quite crazy. leds didnt do much for me.
"If I could make noise with anything, I was going to"

rankot

Re: I've designed a Filter Pedal for Bass
« Reply #66 on: March 25, 2020, 07:09:41 AM »
Interesting. I didn't try with Ge diode, but orange LED is the loudest of all three I tried.
50 pedals and counting!

Rob Strand

Re: I've designed a Filter Pedal for Bass
« Reply #67 on: March 25, 2020, 07:18:41 PM »
I've been meaning to try to understand that circuit for a while.    The way the IC is connected-up is very funky.
The answers are out there for those who want to find them.

rankot

Re: I've designed a Filter Pedal for Bass
« Reply #68 on: March 25, 2020, 07:30:30 PM »
I've been meaning to try to understand that circuit for a while.    The way the IC is connected-up is very funky.

That's far above my level, so I don't try :)

But it seems to be working.
50 pedals and counting!

Rob Strand

Re: I've designed a Filter Pedal for Bass
« Reply #69 on: March 25, 2020, 07:35:39 PM »
Quote
That's far above my level, so I don't try :)

But it seems to be working.
I don't understand it either.   Yes, it clearly works  :icon_mrgreen:
The answers are out there for those who want to find them.