Dr.Boogie debugging

[imzuker]

Hi i have built a Dr. boogie and I connected it for the first time and it doesnt work:
1. It makes a static noise when i turn up the volume.
2. DR.Boogie
3.http://gaussmarkov.net/layouts/drboo/drboo-project.pdf
4.No modifications
5. nope, no substitutions
6.NO ground convertion
7.battery voltage = 8.53 V
8.Voltage at the circuit board end of the red battery lead = 8.53
  Voltage at the circuit board end of the black battery lead = 0

If it matters i didn't connect the 3PDT because it didn't arrive yet, so i just did it like in the schematic. if its not that i will add the voltages of all the parts.
Also i have a 4PDT from the ON/OFF/ON type (i'll add a photo) can i use it as a 3PDT? and how can you show it in a scheme?
http://rocky.digikey.com/weblib/ITT%20Cannon/Web%20photos/TOGGLE%20SWITCH%204PDT%20TO61-1385.jpg (its the 4PDT)

[imzuker]

The Voltages:
Q1
G=0.00
S=0.48
D=0.76

Q2
G=0.89
S=0.31
D=0.31

Q3
G=0.00
S=0.61
D=0.78

Q4
G=0.00
S=0.30
D=0.39

Q5
G=0.39
S=0.0
D=8.37

[The_Armadillo]

Have you adjusted any of the trimpots yet? I've heard or using 4.5v and 5.5v on the drains, someone else will have to verify which one.

I would get the voltages up to around 4.5v then adjust the trimpots to taste.

[imzuker]

i adjusted the voltage in the trimpots to 4.5 (about the half).

[The_Armadillo]

But, its not showing on the voltages you posted. Did you just do this now, or before?

Also, the 4PDT would work just fine for now, its just that one pole wont be used.

[imzuker]

no it was before, and i already got my 3PDT i will connect it as soon as possible.
By the way how can a trimpot be adjusted to 4.5 V? isn't it in Ohms?

[deadastronaut]

its in voltage not ohms.....measure the drains of the fets till you get 4.5-5v...then go from there,...thats the standard method.

however i usually trim by ear though..heres what i do,

turn your guitar down low, now adjust the fets till you don't get any gating, and proper sustain/release...you'll soon see which does what..

once happy, turn up your guitar...should be ok. 

[The_Armadillo]

I agree with deadastronaut. That should get you working.

[imzuker]

umm i had one little problem with the schematic because i didn't know where the drain and the source is so it could be that i put the wrong.

and how am i supposed to adjust the transistor? by adjusting the trimmer?

[J0K3RX]

no it was before, and i already got my 3PDT i will connect it as soon as possible.
By the way how can a trimpot be adjusted to 4.5 V? isn't it in Ohms?

It is in ohms technically it's just an adjustable/variable resistor but what you are needing to measuring using a multi-meter is the voltage coming from the drain of the JFET (transistor) to ground by adjusting the Trimmer.
Watch this: http://www.youtube.com/watch?v=X4-UUDoSCPg

Make sure all your transistors are in correctly according to the gaussmarkov instructions... very important!

Once you figure out how it works like deadastronaut (Rob) said you can do it by ear... You'll get it...!

[imzuker]

I wont be able to do it by ear because it still doesn't work but, i am going to make a PCB and try doing everything from the start

one Last question: How can i know if my transistors aren't working?

[deadastronaut]

checkout this dr boogie layout from rick aka frequency central....on  board pots too..

if you ask him nicely he might have one spare!..

http://www.diystompboxes.com/smfforum/index.php?topic=83671.0


how far did you get with your then?..

if you use a dmm on your fets and turn the trims you'll see if they change...

[J0K3RX]

A picture says a thousand words...

+1 on the frequency central layout! That's the best layout I have seen...

[imzuker]

Do you know the size of the PCB? because i wanna try and make one myself.

and what is a DMM?

[J0K3RX]

Do you know the size of the PCB? because i wanna try and make one myself.

and what is a DMM?

Look here:
http://www.diystompboxes.com/smfforum/index.php?topic=83671.0

DMM is short for a Digital Multi Meter...