No signal through circuit

Started by MickMod, May 25, 2020, 06:52:30 AM

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MickMod

Hello, I've been trying to build an "Assassin of Silence" (https://www.diystompboxes.com/smfforum/index.php?topic=81179.40), but every time i try to build one (Im using this layout: http://i210.photobucket.com/albums/bb292/frequencycentral/Veropots.gif), I just get a very quiet buzzing, guessing it's interference from my power supply.

I swapped the 2N5088's for 2N3904's as that's what I have available to me nowadays.

Is it right that all grounds (jacks, power supply, switch and pots) go to the same ground track? If not, how are they supposed to be wired?

Here's what I've checked:
- I have checked my jacks and they're wired right, because in bypass i still get my clean sound.
- I checked for shorts between tracks, and even ran a sharp knife between them where there could be a microscopic short.
- I checked my trace cuts and they're OK.

I don't know what the issue could be. I'll attach some pics (it ain't pretty) to help show it.

Heres my voltages between the 9v input ground and the legs of my transistors:
Q1:
C: 6.23v
B: 5.39v
E: 0.34v
Q2:
C: 6.10v
B: 5.25v
E: 0.14v
Between + and - on the electrolytic capacitor: 0.14v







MickMod

Here's some more pictures of the bottom of the vero, cleaned off some dust.





antonis

BOTH B-E Voltages are way off..  :icon_wink:

P.S.
Welcome... :icon_biggrin:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

MickMod

#3
Quote from: antonis on May 25, 2020, 07:59:20 AM
BOTH B-E Voltages are way off..  :icon_wink:

P.S.
Welcome... :icon_biggrin:

How would you go about fixing that? And is my grounding correct? This is my first pedal circuit, so I'll need all the help i can get.

antonis

#4
I'd first check for voltage dividers (1M/100k) proper values... Especially for 100k..
Then I'd check for proper grounding of both 100k resistors..

I'm pretty sure that GND point used for measurements take isn't the same with 100k resistors go to..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

MickMod

Quote from: antonis on May 25, 2020, 08:33:13 AM
I'd first check for voltage dividers (1M/100k) proper values... Especially for 100k..
Then I'd check for proper grounding of both 100k resistors..
My current ground is: Grounds of both mono jacks connected to the ground track with every other ground. From what I can see the grounds for the on board components is correct.

antonis

Let's take it the other way....

In case your GND is continously correct, you should take about 800mV measurement on both BJT Bases..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

MickMod

Quote from: antonis on May 25, 2020, 08:39:37 AM
Let's take it the other way....

In case your GND is continously correct, you should take about 800mV measurement on both BJT Bases..
What are BJT bases?
And would having all grounds (components, jacks, pots, and power input) connected together make problems? Because that's how i have it set ut right now.

antonis

The middle legs of transistors..
(those you've measured 5.39V & 5.25V respectively..)

No problem with all GNDs connected on one point..
(that's the way they should be..) :icon_wink:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

MickMod

Quote from: antonis on May 25, 2020, 08:57:59 AM
The middle legs of transistors..
(those you've measured 5.39V & 5.25V respectively..)

No problem with all GNDs connected on one point..
(that's the way they should be..) :icon_wink:
OK good, because when i looked online a lot of people used a stereo jack on input, then ground to the vero, and signal 2 as ground with the 9v input. I'll take a look at the vero then. Thank you for all the help!
-Mick

antonis

Stereo Input jack is used as a "switch" for overall grounding..
(PCB can't be powered unless Input plug inserted to Input jack..)
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..