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Projects => Tech Help - Projects Page => Topic started by: joefox on October 03, 2022, 09:12:34 AM

Title: 3 band parametric equalizer not equalizing
Post by: joefox on October 03, 2022, 09:12:34 AM
Hello.
I purchased and built the following kit:
https://www.musikding.de/3-Band-parametric-EQ-pedal-kit
I can barely hear a sound difference operating the 9 eq knobs.
The only knob  that works is the global volume, making the pedal act as a booster.
I replaced all the chips with new ones, and checked the position and the values of all the components. I would appreciate if someone could give me some suggestions.
Kind Regards
Title: Re: 3 band parametric equalizer not equalizing
Post by: mauman on October 03, 2022, 02:44:13 PM
Welcome to the forum, and congratulations on completing this build!

Some photos of your build would make it easier to help you.  While you're doing that, could you please use a meter to check the voltage from each IC pin to ground, and list them for us?  And here's the build doc for reference.
Title: Re: 3 band parametric equalizer not equalizing
Post by: joefox on October 03, 2022, 07:24:17 PM
Thank you for your kind and quick reply. I think I solved the problem.
According to the wiring  instructions I downloaded from Musikding,
the 9v + and - had to be connected to the pins on the board named A and C.
This caused the power doubler chip to generate 16v instead of 18v. I moved the + to the pin named Vcc and the - to the pin named GND. Now I have 18v and
all works fine.
Thank you again.
Title: Re: 3 band parametric equalizer not equalizing
Post by: mauman on October 03, 2022, 09:50:54 PM
Congrats!
Title: Re: 3 band parametric equalizer not equalizing
Post by: Wizardof_Oz on March 25, 2023, 08:43:32 AM
Hi @joefox, or somebody else,
Would you mind to share the wiring instructions you mentioned for this project on Musikding? I looked all over the site and can't find it...
Cheers