News:

Forum may be experiencing issues.

Main Menu

Pork Barrel Chorus without vibe

Started by desmoben, June 06, 2011, 06:30:41 AM

Previous topic - Next topic

desmoben

Hello all,
bad news, the new IC does not work (sound on IC pin 3 of regular guitar, no sound on IC pin 6).
I have checked all connection to check the pcb.
Everything that is connected to each pin of the IC4 is OK
(pin 1 to IC3 pin1
pin2 to IC3 pin 4
pin3 to R19
pin4 to both C132+ and IC3 pin 8
pin 5 to ground
pin 6 to IC3 pin2
pin7 to pin8 to R20

VD 9.35V
9V 9.43V

What other tests can I do?
Whats going wrong with that pork barrel?
Thanks in advance for any help...

gtr2

Does it have a high pitched squeal on pin 6 when listening with an audio probe?
1776 EFFECTS STORE     
Contract PCB designer

desmoben

No, I have just a crack when I touch the pin and then nothing...
:-(

I don't really know what to test now...

voltages at IC4:

from 1 to 8
9,32
4,53
5,22
8,69
0
4,51
7,54
7,54

Any help please ....

gtr2

woops totally disregard my previous statement...

Your output is pin 7 and 8 of the mn3007.  This is where you should have a signal.  Maybe a problem with the clock?

I may not be much help.  I have not built the pork barrel, hopefully someone who is more familiar with the circuit can chime in...
1776 EFFECTS STORE     
Contract PCB designer

desmoben

When you say problem with the clock, you mean that maybe IC3 is wrong?
(at the origin, both IC3 and 4 were received nearly broken... I supposed that IC4 was KO but with a new IC4 same result.
Maybe problem is linked to IC3 and I should buy one to test it?

What can I do ???

jkokura

Have you verified that you don't have a power to Ground issue still?

Anytime you have a hot battery, that means you have power leaking straight to ground and you have to solve that problem first. Using a powersupply might make it seem like the problem has left, but unless you have verified the problem to be fixed, all the other suggestions I make will be meaningless.

Jacob
JMK Pedals - Custom Pedal Creations
JMK PCBs *New Website*
pedal company - youtube - facebook - Used Pedals

desmoben

Hi,
in fact the batterie was high due to wrong D3 (I inverted it)
So I fixed this problem, and I have no more batterie getting hot.
Now I have plug either the batterie or the boss adapter, btu as batterie just deliver 8V, someone ask to put a "real" 9V in so I plus the boss adapter.

Could you please suggest other tests to perform?

May IC3 be broken?

jkokura

Sounds like it may be the issue, so check things out when you have your replacements in stock.

Jacob
JMK Pedals - Custom Pedal Creations
JMK PCBs *New Website*
pedal company - youtube - facebook - Used Pedals

desmoben

Yes, that was the issue.
At least with that problem I have built my audio probe and will be helpfull with other debugging.
Thanks for your help.