Hi guys.....having trouble with my snarkdoodle.....I have just a white noise for output. Volume pot works but gain has no effect....where do I even start? Thanks for any help
Start here...this will help you locate the information you need to obtain help from the many great members of the forum. Without detailed information, it's near impossible to troubleshoot. Welcome to the forum! :)
http://www.madbeanpedals.com/forum/index.php?topic=902.0 (http://www.madbeanpedals.com/forum/index.php?topic=902.0)
What's the sound path for this circuit? I'm not good at schematics
IN1, R2, C1, IC1A, (feedback loop: C2, R3, R4, GAIN), C3, IC1B, (feedback loop: C4, R5), C5, VOL, OUT1.
Essentially everything in the upper half of the schematic...
Quote from: kothoma on December 10, 2013, 11:10:32 PM
IN1, R2, C1, IC1A, (feedback loop: C2, R3, R4, GAIN), C3, IC1B, (feedback loop: C4, R5), C5, VOL, OUT1.
Essentially everything in the upper half of the schematic...
Thank you :)
Here's my voltage readings for the ic
Volts in-9.4
Pin 1-6.4
Pin2-6.4
Pin3-0
Pin4-2.38
Pin5-2.42
Pin6-6.4
Pin7-0
Pin8-0
Pin9-0
Pin10-6.4
Pin11-0
Pin12-6.4
Pin13-0
Pin14-0
Pin15-0
Pin16-0
All these zeros don't seem right to me.
Here's a few pics if someone could please help me with this.
I know I should have socketed but I didn't have one....I forgot when I made my parts order
Pin 1 is very low. :( What did you use for R7? (All these 6.4V seem strange.)
Not sure what 2/3/4/5 are supposed to have. But let's look at the remaining pins.
Pin 15 should have the same voltage as 6/10/12. :(
Pins 7/8/9/11/14 having 0V is OK, they're grounded.
Pins 13/16 are irrelevant.
What's with all the black areas on your second picture? is it just some weird lighting on flux residue or are you actually burning the board? It really shouldn't look like that... ???
Also, do you have an audioprobe?
Yeah. How far did you get with your audio probe?
Also, that CD4049UBE is a CMOS device. You know these are sensitive to electrostatic discharge and have handled it with care?
Quote from: muddyfox on December 11, 2013, 09:43:30 AM
What's with all the black areas on your second picture? is it just some weird lighting on flux residue or are you actually burning the board? It really shouldn't look like that... ???
Also, do you have an audioprobe?
The black is just weird lighting....it rubs off. And yes I have an audio probe. I'll see how far I get with it after work today....got flustered last night and stopped
Quote from: kothoma on December 11, 2013, 09:31:32 AM
Pin 1 is very low. :( What did you use for R7? (All these 6.4V seem strange.)
Not sure what 2/3/4/5 are supposed to have. But let's look at the remaining pins.
Pin 15 should have the same voltage as 6/10/12. :(
Pins 7/8/9/11/14 having 0V is OK, they're grounded.
Pins 13/16 are irrelevant.
I quadruple checked all values....but I'll check again this evening.
Quote from: kothoma on December 11, 2013, 10:12:39 AM
Yeah. How far did you get with your audio probe?
Also, that CD4049UBE is a CMOS device. You know these are sensitive to electrostatic discharge and have handled it with care?
Yes....I handle all ic's with care. I'll see how far I get with my probe after work.