250+ no distortion only volume boost

[R-Man]

Hey everyone, I am new to this, you might have read my thread called "Personal Best Project"

1. Name of the project: 250+ from B.Y.O.C (built to DOD 250 specifications)

2. Links: http://buildyourownclone.com/250instructions.pdf http://www.buildyourownclone.com/250.html

3. followed the instructions entirely except for the diodes, I changed the jumper to a 1n914 orange diode and I put it in NOT matching the diagram so the black stripe was downwards pointing.


4. I wrote my modification above.

5. Whether or not it's a positive ground circuit like a PNP fuzz or a Range master that has been hacked to work with negative ground. This is a special case, but a common one. "Positive ground" means that the positive/red lead of the battery clip is connected to signal ground. "Negative ground" means that the negative/black lead of the battery clip is connected to signal ground when the effect is operating.  NEGATIVE GROUND

6.  I am getting no distortion at all! The drive pot does something but I'm not sure how to describe it, makes the sound more boomie/chunkier, the volume pot works fine.

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? =>8.51v

Now insert the battery into the clip. If your effect is wired so that a plug must be in the input or output jack to turn the battery power on, insert one end of a cord into that jack. Connect the negative/black meter lead to signal ground by clipping the negative/black lead to the outer sleeve of the input or output jack, whichever does not have a plug in it. With the negative lead on signal ground, measure the following:
Voltage at the circuit board end of the red battery lead =
Voltage at the circuit board end of the black battery lead =

Now, using the original schematic as a reference for which part is which (that is, which transistor is Q1, Q2, etc. and which IC is IC1, IC2, C1, and so on) measure and list the voltage on each pin of every transistor and IC. Just keep the black lead on ground, and touch the pointed end of the red probe to each one in turn. Report the voltages as follows:

IC1 (or U1)= 741
P1=0.01v
P2=4.21v
P3=3.82v
P4=0.0v
P5=0.0v
P6=8.45v
P7=4.22v
P8=0.01v

____
|1   5|      IC's pin layout
|2   6|     
|3   7|
|4   8|




D1 (right) 1n914
measurement: 775

D2 (center) 1n914
measurement: 772

[GREEN FUZ]

3. followed the instructions entirely except for the diodes, I changed the jumper to a 1n914 orange diode and I put it in NOT matching the diagram so the black stripe was downwards pointing.

As diodes are polarized it`s important that they are inserted the right way. The quality of the distortion is very dependant on these components so it`s worth checking that they are the right way around.

[R-Man]

i took it out now, its got the jumper in it so it is completely dod 250 stock specifications,
still no distortion 

[GREEN FUZ]

And the remaining diodes are the right way round?

[petemoore]

P1=0.01v
P2=4.21v
P3=3.82v
P4=0.0v
P5=0.0v
P6=8.45v  This pin should be near 1/2v, it is output
P7=4.22v  This pin should be near V+ it is V+
P8=0.01v
  Kinda looks like something wierd with the output and V+ wiring...perhaps the pin assignments have reversed wiring..
  I would check that Pin7 connects to nothing, except V+.
  pin 6...should also have it's wiring assignments Dmm tested.
  i would connect V+ to pin 7, test for shorts across the battery clip or pS, then take new voltage measurements.
  pin 7 is pretty simple, if the circuit doens't work with V+ correctly wired, I would test that pin 6 has correct wiring assignments.

[MikeH]

The IC pin layout is actually this:

1      8
2      7
3      6
4      5

[R-Man]

The IC pin layout is actually this:

1      8
2      7
3      6
4      5

what i meant was where i wrote P5's measurements, that was the top right corner pin

[R-Man]

to avoid confusion i'll re write out the IC pin measurements correctly (sorry!)

IC1 (741)
P1=0.01v
P2=4.21v
P3=3.82v
P4=0.0v
P5=0.01v
P6=4.22v
P7=8.45v
P8=0.0v

[R-Man]

if i turn the volume and drive on full i get distortion but its really lame it sounds like a bunch of fuzz along with a clean guitar sound

[oldrocker]

Is there a way for us to see the back side of the board?  I was trying to trace down the layout but some traces are on the other side.