madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: Guybrush on September 11, 2013, 08:01:13 AM

Title: Weird Zombii Issue
Post by: Guybrush on September 11, 2013, 08:01:13 AM
Hey all

I recently built a Madbean Zombii and it all worked perfectly. However over the last week it has developed a high pitched whistle whenever the pedal is engaged.

I know it is inherently a noisy circuit but it didn't start making this noise until very recently which is obviously annoying.

I can dial it out by turning the Comp knob up to full but anything less than that and the whistle comes back.

Anyone have any ideas?

Thanks.
Title: Re: Weird Zombii Issue
Post by: lincolnic on September 11, 2013, 03:15:23 PM
I'm pretty sure it's supposed to do that. Did you turn your Stability knob down?
Title: Re: Weird Zombii Issue
Post by: Guybrush on September 12, 2013, 08:47:46 PM
Yeah, I've turned all the knobs and tried different settings but to no avail. The only thing that works is having the gate or compression knob fully dialled but that obviously has an effect on the sound.

It's strange though because when I first built it it definitely didn't do it. I'm starting to wonder if it's an issue with my power supply. I might build the Beavis Audio power filter to see if that helps.

Cheers.

Title: Re: Weird Zombii Issue
Post by: jimilee on September 12, 2013, 09:12:08 PM
I was gonna say, have alook at the power supply. Have you built a 9volt battery adapter yet? It's just a battery snap with a barrel adapter on it. Great for quick and dirty tests. I saw jacob do that in one of his build pictures.
Title: Re: Weird Zombii Issue
Post by: icecycle66 on September 12, 2013, 10:31:58 PM
Quote from: lincolnic on September 11, 2013, 03:15:23 PM
I'm pretty sure it's supposed to do that. Did you turn your Stability knob down?

I love this:

"It sounds broken"

"That means it's working."
Title: Re: Weird Zombii Issue
Post by: lincolnic on September 13, 2013, 02:30:24 AM
Quote from: Guybrush on September 12, 2013, 08:47:46 PM
It's strange though because when I first built it it definitely didn't do it. I'm starting to wonder if it's an issue with my power supply. I might build the Beavis Audio power filter to see if that helps.

This might be it, actually. The Stability control is just a voltage starve, as far as I can tell, so if the pedal isn't getting a proper voltage, maybe it's acting like the Stab pot is already turned down. Are you getting a full 9v (or near enough) from your power supply?