Help With BSIAB II De-bug

[JT]

Hey guys need help with my BSIAB . Pedal has no sound . I am using a GGG board and layout
Schem: http://www.generalguitargadgets.com/diagrams/bsiab_2_sc.gif

Layout:

http://www.generalguitargadgets.com/diagrams/bsiab_2_lo.gif

As far as i can tell i have it wired correctly. I do not know how to post an image but i can search the forums to see if there is a post on how to do so.

Here are my voltages


Battery - 8.33

Q1 :
G- 0V
S- .858V
D- 4.5V

Q2:
D- 8.0V
S- 4.5V
G- 3.66V

Q3:
G- 0V
S- 0.90V
D- 3.91V

Q4:
D- 7.66V
S- 3.92V
G- 3.64V

Q5:
G 0V
S-.644v
D- 4.2V


Here is the voltage chart from GGG:



http://www.generalguitargadgets.com/diagrams/bsiab2_voltage_diagram.gif


Any help would be appreciated .
Thanks
JT

[petemoore]

Hey guys need help with my BSIAB . Pedal has no sound . I am using a GGG board and layout
Schem: http://www.generalguitargadgets.com/diagrams/bsiab_2_sc.gif

Layout:

http://www.generalguitargadgets.com/diagrams/bsiab_2_lo.gif

As far as i can tell i have it wired correctly. I do not know how to post an image but i can search the forums to see if there is a post on how to do so.

Here are my voltages


Battery - 8.33

Q1 :
G- 0V
S- .858V
D- 4.5V
 The gate is near supply, check pin orientation on this one

Q2:
D- 8.0V
S- 4.5V
G- 3.66V
 This ones close to GGG values, source above gate...

Q3:
G- 0V
S- 0.90V
D- 3.91V
 ""       """       """

Q4:
D- 7.66V
S- 3.92V
G- 3.64V
 I think it's operational, Ill have to recheck GEO jfet article

Q5:
G 0V
S-.644v
D- 4.2V
 source is higher than drain, can't work, look for problem here.
 >>Is this a perf or pcb or...?

Here is the voltage chart from GGG:



http://www.generalguitargadgets.com/diagrams/bsiab2_voltage_diagram.gif


Any help would be appreciated .
Thanks
JT

[JT]

Thanks for the response Pete!


Battery - 8.33

Q1 :
G- 0V
S- .858V
D- 4.5V
The gate is near supply, check pin orientation on this one

Orientation is as per GGG layout and the Values seem very close to GGG

Q2:
D- 8.0V
S- 4.5V
G- 3.66V
This ones close to GGG values, source above gate...

Q3:
G- 0V
S- 0.90V
D- 3.91V
"" """ """

Q4:
D- 7.66V
S- 3.92V
G- 3.64V
I think it's operational, Ill have to recheck GEO jfet article

Values seem very close to GGG

Q5:
G 0V
S- .644v
D- 4.2V
source is higher than drain, can't work, look for problem here.

Values seem very close to GGG
>>Is this a perf or pcb or...?
Its a GGG PCB

[KORGULL]

petemoore wrote:

Q5:
G 0V
S-.644v
D- 4.2V
source is higher than drain, can't work, look for problem here.

Look again pete, drain is 4.2V - source is 644mV - so source is not higher than drain.
I'd check the wiring of the pots and jacks a couple more times.
Sorry that's all I can think of to tell you.

[JT]

Thanks Korgull!

[theguy316]

hey guys im having the same problem but im not as crafty as u all are so maybe u all can help me out... im pretty sure everything is wired correctly on the bsiab II but no sound when turned on... the led doesnt turn on either... another problem is that the battery gets unusally hot but i moved some wires around on the input and the hot battery problem stopped.. and the pedal made a fluttering sound... well after screwing with the wires on the jacks im back at square one with the pedal not working when its on... i see that u all are able to take voltage readings with a mutimeter and i wanted to know how you all do that... i have a multimeter and ive been unable to get any other readings other than 8.** which i guess is just the battery... how do i get any readings from the transistors... any help would be appreciated to fix this pedal... this is my first build and its on a PCB which i made myself ... well please help!!!

[b_rogers]

maybe try the audio probe trick to see where the signal stops?


Brent

[KORGULL]

how do i get any readings from the transistors.

With the meter set to test Voltage...
Connect your meter's black probe to a ground point of the circuit - a jack sleeve solder lug for example.
Use the other probe to touch each leg of the transistors or IC to get a Voltage reading.

The battery getting hot sounds like you have the power + shorted to ground somewhere.

Make sure the wiring to the switch and jacks is really done correctly.