DR BOOGIE NOT WORKING

[seagurt]

1.What does it do, not do, and sound like?
- LED lights up, bypass gives no sound (audio in not working) audio out works (when unit is engaged, and tip is touched, gives tapping noise) also when unit is on, there is audio interference, but only from the board out. The only pot working is the volume which is connected to the mono out jack.

2.Name of the circuit =
-Dr Boogie V2

3.Source of the circuit (URL of schematic or project) =
http://tagboardeffects.blogspot.ca/
Saturday March 10, 2012 (one needs to go back through the posts to this date to find the layout)

4.Any modifications to the circuit? Y or N
-Added a DC jack
-installed a stereo (TRS) input jack

5.Any parts substitutions? If yes, list them.
-1.8k (instead of 1k) resistor tied to a blue LED.
-Shielded audio input, with ground from cable attached to ground on board
-Treble pot is a 50K linear (calls for logarithmic) 
-mid pot is a 2k linear

6.Positive ground to negative ground conversion? Y or N
-Not to my knowledge

7.Turn your meter on, set it to the 10V or 20V scale. Remove the battery from the battery clip. Probe the battery terminals with the meter leads before putting it in the clip. What is the out of circuit battery voltage? =>
-9.44V DC

Voltage at the circuit board end of the red battery lead = 9.19V DC

Voltage at the circuit board end of the black battery lead = No reading, my black lead coming from the battery snap, is attached to input Ring (TRS) on my stereo input jack.

Q1
D- .99V DC
S- .28V DC
G- .29V DC

Q2
D- 1.01V DC
S- .30V DC
G- .30V DC

Q3
D- 1.26V DC
S- .55V DC
G- .56V DC

Q4
D- 7.78V DC
S- 6.90V DC
G- 6.96V DC

Q5
D- 8.58V DC
S- 7.78V DC
G- 7.77V DC

I was trying to upload photos... Can someone point me in the right direction?

Any and all help is appreciated.

Thanks guys!

[J0K3RX]

Your voltages are not looking good From the +9V it then goes through a 100 ohm resistor. What voltage do you have on the other side of that resistor?

[seagurt]

I am getting 8.02V DC.

I biased the JFETS, though the last pot doesnt seem to impact Q4.
New readings are as follows.

Q1
D- 5.08V DC
S- 4.29V DC
G- 4.29V DC

Q2
D- 5.27V DC
S- 4.47V DC
G- 4.49 V DC

Q3
D- 5.36V DC
S- 4.58V DC
G- 4.60V DC

Q4
D- 7.28V DC
S- 6.47V DC
G- 6.49V DC

Q5
D- 7.3V DC
S- 6.57V DC
G- 7.26V DC

[J0K3RX]

Can you get Q1-2 and 3 to go a little lower? You should have some sound coming through now?

[ggedamed]

Audio probe it starting from the beginning of the circuit.

[Pojo]

Never built one of these but from all other JFET based pedals I've built tells me those voltages are still way off. The only terminals on the fets that should be near 4.5V-5V are the drains. The gates should be 0v and the sources should all be only a small fraction of a volt. Certainly under .5V. How are you measuring them? The black probe on your DMM should be clipped to ground as you touch the red probe to each terminal. If that's what you're doing then it's possible the JFETS are fake...certainly plenty of them going around especially if you bought from a Chinese ebay store or any other questionable source.

[vigilante397]

If you're not even getting sound when bypassed I would say start with that before tackling the circuit. "audio out works" means your amp works, nothing more. Look at how your switch is wired, test connectivity with a multimeter, and get your bypassed sound working.

[J0K3RX]

Mike G is right... I didn't see or pay attention to the other voltages other than the drain for some reason.. I blame it on this damn iPhone  .  One thing that I don't do when I am testing a new board is hook up the switching for a couple reason, 1. I am lazy 2. That is how I started and now it is a habit 3. I started doing it that way to rule out mis-wiring, run it directly... Just what I do and probably a good idea if you are new at this. Not to knock vero board but I had miserable luck with it when I started and I have not touched it since and needless to say I have been fairly successful with my builds ever since. If I were you I would go over the whole thing part by part and make sure they are all the correct value and they are placed where they should be. While you are doing that also make sure you don't have any solder bridges and make double sure you have all of your cut and that they are in the correct places etc.. These look easy but it is easy to miss something while paying attention to something else. Also make sure you are getting your voltage readings from the correct places..

[seagurt]

Hello all,

Thank you for your attention to this matter.

I do apologize for not being around, Google didn't notify me of new messages.

As such, I went to another board to try and solve my issue. It has yet to be resolved, but I thought I would share what has been looked at.

The following link is to the "other" page where I posted my fault diagnosing info.

http://guitar-fx-layouts.42897.x6.nabble.com/Dr-Boogie-build-issues-td17616.html#a17774

The info on where my audio probe cuts out, and other things are included. I figure it is easier to just go to the site, as opposed to me just cutting and pasting.