madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: rawkcraze on January 30, 2012, 11:23:57 PM

Title: Sea Urchin, No delay
Post by: rawkcraze on January 30, 2012, 11:23:57 PM
today i build the Sea Urchin delay pedal.
it has a dry singal coming through without any problems, but there's no delay.
ive checked, and double checked all the capacitors orientation, and they're all correct.
the voltage regulator is a big, Lm7805c.
also, the pt23999 is getting hot on the bottom half of it.
i cant find voltages for this on the website or anywhere else so i have nothing to compare to. but hopefully you guys can help me out.

heres the Voltages im getting.
input voltage- 9.5v

PT23999:
1-5v
2-2.49v
3-0
4-1.9v <-problem
5-4.97v
6-2.94v
7-352mv
8-4.62v
9-4.81v
10-.782v
11-2.49v
12-2.49v
13-2.49v
14-2.48v
15-2.49v
16-2.49v

Tl072
1-3.6
2-3.5
3-3.5
4-0
5-3.5
6-3.5
7-3.44
8-7.02v

Reg:
In-6.9v
G-0
out-5v

thanks
Title: Re: Sea Urchin, No delay
Post by: rawkcraze on January 31, 2012, 12:08:26 AM
the 33ohm resistor is the part thats getting hot, not the IC, just to clarify.
still not getting any delay..
Title: Re: Sea Urchin, No delay
Post by: jkokura on January 31, 2012, 12:24:50 AM
If the 33R resistor is getting hot, that would indicate that something's up with your power.

I would also expect pin 4 to be 0V. The fact that you get a drop of 2.5V getting to pin 8 of your TL072 is indicating there's a power problem too. I suspect either that you have an incorrect/backwards part or that you have a solder bridge.

Jacob
Title: Re: Sea Urchin, No delay
Post by: madbean on January 31, 2012, 01:35:49 AM
I think your regulator is not working properly. Look at your voltage on pin8 of the TL072 - it should be about 9v (assuming you have a 9v supply). Also, your voltage into the regulator is less than 7v.

Could be the pinout of that regulator is not the same as the 7805 the PCB is designed for.