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Projects => Tech Help - Projects Page => Topic started by: Guitar Master on August 03, 2013, 11:28:52 PM

Title: Zero Point DD question
Post by: Guitar Master on August 03, 2013, 11:28:52 PM
Hey guys,
I built a Zero Point DD to specs except for the 78l05 which I accidentally ordered the L7805CV from tayda. Anyhow, the thing works great except after 2 minutes or so of playing it starts screaming likt its  from the twilight zone. It scared me to death the first time I heard it.

Also, the ghost mod can't be heard super well if at all (is this how it is supposed to be?)

Any help would be excellent!

Thanks
Title: Re: Zero Point DD question
Post by: madbean on August 04, 2013, 01:17:24 AM
What is your voltage reading on the output pin of the 7805? Are you still getting 5v to the PT2399 when the noise starts?

You can increase the volume of the repeats in Ghost mode by lowering the two feedback resistors: R21 and R22.  I chose the values in the schem to be not too loud or too soft, but you can certainly lower them to your preference. Sockets would be a good idea.
Title: Re: Zero Point DD question
Post by: Guitar Master on August 04, 2013, 02:46:32 AM
You just made my day Madbean!

I was getting like 5.5 volts until the noise happens, and then it drops to like 3 volts. Looks like i'm gonna need to swap that guy out. I'll also test out the ghost resistor values.

Thanks again! It amazes me at how much you know about these types of things. The delay sounds great when it does work by the way.