Build Your Own Clone Message Board

Hi there, I completed an analog chorus build and noticed that the pedal doesn't have a good clean chorus effect. I also noticed that the trim pot is kind of scratchy/static-y. I can slowly dial through the entire range and 'find a sweet spot' to get the chorus effect, but I also hear a lot of hum when I find the effect and the pedal is just on when I'm not strumming.

When I do strum, there's a light 'distortion' effect as well. Could there be something wrong with the trim pot? Thanks!

There are a lot of things that can cause your symptoms. Please post well-focused and lighted photos of your build, including both sides of the pcb. We will have a look and see if we can help you out.

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MasterDelayer/Reverbrador/Ampaholic/TopJacker

I reflowed all the soldering before posting - here are some pics. Please let me know if I should add more. Thanks for taking a look!

If you pull the mn3207 out of its socket (the chorus will go away) is the hum still there?

Do you have a DMM and are you able to take voltage readings?

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MasterDelayer/Reverbrador/Ampaholic/TopJacker

Your soldering needs a lot of improvement. The input and output jacks are clearly cold solders. I can’t see the stomp switch very well but it appears to have cold solders as well. In the first photo just to the right of the pot on the left I can still see most of the solder pad. A quality solder joint will cover the entire pad. Two solder joints above that you have a solder that looks like a thorn. This is another cold solder joint. A quality joint will never look like the top of a DQ soft-serve icecream cone. The little pigtails of component lead sticking thru most of your solder joints all need to go. These are all short circuit risks. The lead should be cut off right at the top of the solder joint. There should be nothing poking thru the top of the solder joint.

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"It’s your soldering."

The soldering on the PCB looks very good, though, except for those "pigtails" that need to be clipped. It's the wire connections to the jacks and footswitch that need work. Here's a tip for the I/O jacks: the solder tabs on these jacks have some sort of thin coating on them that impedes the wetting action of the molten solder and causes it to "ball up" and may result in the dreaded cold joint. I suggest scuffing them up with a bit of sandpaper before soldering, which exposes fresh metal surface and allows the solder to wet the surface properly. Makes a BIG difference.

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“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

I took the socket out and noticed the hum clear up quite a bit. I can measure voltage, what should I be looking for?

The 4558 should have about 9 volts DC on pin 8, 0 volts (ground) on pin 4, and about 1/2 the voltage of pin 8 on the rest of the pins. You should be able to dial in 1/2 voltage on the others pins using the trim pot. When installed, the 3207 should have around 4.5 volts on pins 7 and 8.

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MasterDelayer/Reverbrador/Ampaholic/TopJacker

Do you still have the ‘light distortion’ when the 3207 is removed?

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MasterDelayer/Reverbrador/Ampaholic/TopJacker