madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: MADWAGNER on June 25, 2014, 09:20:56 PM

Title: Zero Point Mini Feedback Pot
Post by: MADWAGNER on June 25, 2014, 09:20:56 PM
Hi guys!
I got my Zero Point Mini working. But the Feedback pot doesn't do the infinite repeat when turned all the way up. It works put doesn't go to full range. Also my ring mode switch doesn't do anything. I think that it's tied to feedback pot somehow, but not sure. Any help with where in circuit I should start looking at would great.

Jeremy
Title: Re: Zero Point Mini Feedback Pot
Post by: m-Kresol on June 25, 2014, 10:26:30 PM
Hi Jeremy,

nice to hear your delay is working. Still, it's almost impossible to help you without any pictures or voltages. Please post a picture of your component and solder side, so we can check for component value, orientation and the like.
cheers, Felix
Title: Re: Zero Point Mini Feedback Pot
Post by: MADWAGNER on June 25, 2014, 10:38:01 PM
Thanks!
I will, but already posted a thread when I was originally debugging this. That thread died a quick death.
Pictures and voltages are here
http://www.madbeanpedals.com/forum/index.php?topic=15458.0
I'll double check the voltages.
I was pretty lucky to get it going in the first place.
thanks
Jeremy
Title: Re: Zero Point Mini Feedback Pot
Post by: madbean on June 25, 2014, 11:53:07 PM
You can increase the repeat range by lowering R18. Try 1k or 470R.
For the Ring switch, it's easiest to hear it when you have the delay set medium to long, the feedback and mix halfway up or more. Listen to the decay on the delayed notes. When the Ring switch is activated, they should get a little bit dirtier and less defined than when it is off. If not, then perhaps you have the wrong value resistor in R15. Or, you can decrease R15 to increase the intensity of the effect, say 39k.
Title: Re: Zero Point Mini Feedback Pot
Post by: MADWAGNER on June 26, 2014, 07:05:39 AM
Thanks! That was it. I had a 15k for R18. One odd thing is the feed back and tone pot seem to be connected. I get infinite repeats and the ring mode works, but only when the tone pot is turned about 40% to all the way off.
It sounds pretty sweet.
I was wondering if there is a way to limit the delay time? As it gets a little noisy at long settings.
Thanks for the help
Jeremy

Update: I soldered a 22k resistor parallel to the time pot to lower the delay time. :)
Title: Re: Zero Point Mini Feedback Pot
Post by: madbean on June 27, 2014, 02:40:33 PM
I would actually go up to something like 220k - 470k for the parallel resistor. It will limit the delay but not so much as a 22k.

The tone pot will be somewhat interactive with the feedback pot because you are rolling off high end with the tone pot. This reduces the signal mix back into the delay chip which is why the feedback pot needs to be turned up a bit more when you are cutting tone.
Title: Re: Zero Point Mini Feedback Pot
Post by: MADWAGNER on June 28, 2014, 08:11:43 PM
Thanks Brian! I'll change it out today. That makes sense about the tone pot. That's a pretty awesome feature! I'm gonna box it up today finally.  8)

Thanks again!