Pt2399 hum/buzz

[VolksWilliam]

Hi guys. First post here. Been lurking for some time now.

Question:

I recently built a 2399 lofi delay. It worked first try! Never happens for me. Only problem is when I use it in my pedal board which is powered by daisy chain I turn it on and all it does is make a very loud buzzy hummish sound. Curious if anyone has had this happen to them? Is it just not getting the correct power ? It works great when I plug it in by itself.

Thanks guys!

[Kesh]

Your pedal board power supply could be inadequate. What current is it rated at?

2399 can require a lot of current, up to 100mA, but usually less. It's usually powered by a voltage regulator that needs about 7V, often the barely adequate 78L05.

If the current draw is pulling the power supply voltage down near to 7V the unit will misbehave. Though many other pedals will sound fine at 7V, sometimes better.

That would by my first line of investigation.

[VolksWilliam]

Your pedal board power supply could be inadequate. What current is it rated at?

2399 can require a lot of current, up to 100mA, but usually less. It's usually powered by a voltage regulator that needs about 7V, often the barely adequate 78L05.

If the current draw is pulling the power supply voltage down near to 7V the unit will misbehave. Though many other pedals will sound fine at 7V, sometimes better.

That would by my first line of investigation.

That's what I was thinking. Didn't realize that most pedals can be ran that low. It says it takes 9v 200mA. I'm running a VooDoo pedal power. It even does it when I take it out of the chain and plug it into its own spot on the voodoo. Weird?

[Kesh]

Voodoo pedal power should give enough power.

Are you saying it only works on battery? If so it's probably your wiring that went wrong when you made it.

[pinkjimiphoton]

sounds suspiciously like the problem i had been having with my rebote delay..

bet your regulator is fried, check to see if it's actually putting out 5v. if it isn't, check this thread:

http://www.diystompboxes.com/smfforum/index.php?topic=99676.0

i haven't had a chance to implement the "fix" yet, but this may help you out some i hope.

[VolksWilliam]

Works on battery. Yes. Works when plugged into boss 9v 200mA power supply. Yes. Does not work when plugged directly into or daisy chained into voodoo power.

Unusual. I know. That's why I'm confused.

[Kesh]

have you tested the voltage coming out of your voodoo? Maybe your voodoo is not functioning properly, and you are only noticing it on this more voltage sensitive pedal.

[syntaxera]

from what I understand it's not possible to get the hum/buzz out of a PT2399...  it's in it's nature.  I have built a few PT2399 delays, they are all pretty noisy and unstable to the point of almost not wanting to use it.  For a weird synth machine.... yes,  as part of my guitar effects chain..  no. 

[Ark Angel HFB]

http://www.beavisaudio.com/projects/Huminator/index.htm

Drop the LED and the 3.3k pull down resistor from the circuit and add it to the front of your build... If you problem is a poorly filtered power supply this will solve it.