madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: blearyeyes on August 08, 2014, 01:09:01 AM

Title: ZPSDK feedback control is into runaway at 12 noon, want to tame it a bit...
Post by: blearyeyes on August 08, 2014, 01:09:01 AM

Should be simple to figure out but I can't!

My ZPSDK feedback control is into runaway at 12 noon.   I would like to tame it so runaway is closer to 3 o'clock to wide open.
Do I want to lower the feedback pot's resistance to get less feedback?

Here's the docs:
http://www.madbeanpedals.com/projects/ZeroPoint/ZeroPointSDX.pdf (http://www.madbeanpedals.com/projects/ZeroPoint/ZeroPointSDX.pdf)

I looked at the schematic and found myself staring into the depths of the Mind of Bean... and my head started to spin...
Title: Re: ZPSDK feedback control is into runaway at 12 noon, want to tame it a bit...
Post by: timbo_93631 on August 08, 2014, 01:30:01 AM
Substitute a 50kA pot, should give it a little more fine control on the working range before oscillation and bunch the oscillation up nearer the end of the rotation.  I used 50kA's on a bunch of ZPDD's and it worked great!
Title: Re: ZPSDK feedback control is into runaway at 12 noon, want to tame it a bit...
Post by: jimilee on August 08, 2014, 01:47:32 AM
Did you search the forum? It's been the topic of numerous threads. I can't tell you how to make it stop though, I'm sorry.
Title: Re: ZPSDK feedback control is into runaway at 12 noon, want to tame it a bit...
Post by: lincolnic on August 08, 2014, 03:51:36 AM
It was recommended to me that I solder a 10k resistor across lugs 1 and 2 of the feedback pot, but I haven't gotten around to trying it yet.
Title: Re: ZPSDK feedback control is into runaway at 12 noon, want to tame it a bit...
Post by: blearyeyes on August 08, 2014, 08:08:59 PM
Quote from: jimilee on August 08, 2014, 01:47:32 AM
Did you search the forum? It's been the topic of numerous threads. I can't tell you how to make it stop though, I'm sorry.

Well I have to admit I didn't search the forum and that is kinda a basic thing to do before you waste bandwidth.....duh.
Sorry about that...

Thanks you guys!