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DIY Stompboxes => Building your own stompbox => Topic started by: DUCKFACE on July 28, 2022, 12:35:06 PM

Title: small clone not working
Post by: DUCKFACE on July 28, 2022, 12:35:06 PM
help ... again :(
i have a problem with EX smallclone chorus pedal that im building.
im usin gthe schematic as follow:
(https://i.postimg.cc/Mv0qq9NT/shcematic.png) (https://postimg.cc/Mv0qq9NT)


The result - i can control the rate and the wight of the LED but the sound is not changeing at all. im using 3207 instead of 3007. On the output i can hear clear guitar and pulsing tichks with the same speed as the leds flashing. 
When i make short with my finger (the middle one) between the points of the shcematic and the ground eveyrthing is just right.

The problem is that i can't play on the guitar with the finger (middle one) puted on that poit of the effect instead on the fingerboard.

any advices ?


Title: Re: small clone not working
Post by: Fender3D on July 28, 2022, 01:12:43 PM
This schematic is wrong!
You need to pull outputs pins down to gnd, connect R5 to pins 7,8 and gnd instead of vcc
Title: Re: small clone not working
Post by: idy on July 28, 2022, 01:34:39 PM
Did you make the changes that are required when changing 3007 to 3207? ...the power supply is reversed for 3207...
Title: Re: small clone not working
Post by: ElectricDruid on July 28, 2022, 01:45:10 PM
In my view, that schematic is horrible generally, whether it is wrong or right.

There are different voltage points all over it with no logic, the signal path is chaos, there are pots back-to-front, etcetc. I've been reading schematics for probably 35 years and I can't make head nor tail or it at first glance. That's a massive clue to me that this isn't an easy read! There's some stuff that it does seem to do ok (there's a general signal flow left to right, for example) but it doesn't make most things clear, and it doesn't break stuff up into logical blocks.

The reason that this *matters* is because the easier the schematic is to understand, the easier you'll spot errors in it. And if you're sure there are no errors in your schematic, you can get the computer to make sure there are no errors in your PCB. But the first step is having a nice, clear schematic.
Title: Re: small clone not working
Post by: DUCKFACE on July 31, 2022, 06:48:42 AM
Quote from: Fender3D on July 28, 2022, 01:12:43 PM
This schematic is wrong!
You need to pull outputs pins down to gnd, connect R5 to pins 7,8 and gnd instead of vcc
thanks. i forgot to change the pull out resistor from vcc to gnd.
but when i change it the sound dissapear at all.

edit: weak joints on the output. everything is working now exept that i can hear the LFO in the output when the blend pot is on full right position.