Debugging Barber Silver LTD second build attempt

[lazerphea]

Here we go again... second attempt at building this pedal, failed again :\

1.What does it do, not do, and sound like?
Sometimes it distorts (not a very pleasant distortion, especially if I lightly struck the guitar strings... kind of "frying" sound), sometimes not; when distorting, if I struck my guitar strings harder, it stops distorting.
All the pots and trimmers work ok.
2.Name of the circuit
Barber Silver LTD
3.Source of the circuit (URL of schematic or project)
Schematic
I perfboarded it, and I used my own layout: Barber Silver perf layout
4.Any modifications to the circuit Y or N
No
5.Any parts substitutions? If yes, list them.
The presence 10Kb trimmer has been substituted with a 4.7K resistor.
6.Positive ground to negative ground conversion? Y or N
No
Circuit battery voltage
9.7V
Voltage at the circuit board end of the red battery lead
9.7V
Voltage at the circuit board end of the black battery lead
0.0V
Plus, the voltage divider provides 4.76V

All the electrolytic caps and the diodes are oriented correctly.

Opamp 4558 pins voltages
1. 4.75
2. 4.65
3. 4.50
4. 0
5. 4.18
6. 4.71
7. 4.94
8. 9.37

Thanks to everyone willing to help

[mmaatt25]

I built one of these earlier this year, nice overdrive pedal. I'll have a measure of some voltages later and post them.

As you are getting some signal I would use an audio probe. Plenty of threads regarding making/using.

Matt

[lazerphea]

Thanks a lot, Matt!

[stringsthings]

how did you get 9.7 volts as a power supply?

is there a reduction from your power supply to get to 9.37v?

[lazerphea]

how did you get 9.7 volts as a power supply?

is there a reduction from your power supply to get to 9.37v?

Maybe I didn't understand your question, but I'm using a battery to power the circuit. 

[lazerphea]

Any idea?

[lazerphea]

I was looking at my build (again and again...), and I found out I used a1N4148 instead of a 1N4001 in the voltage divider: could this be the problem: the pedal sometimes works fine, but if I strike my guitar strings a little harder it produces a clean sound. I found out that I can make it distort again removing the battery a couple of times... 

[jkokura]

Do you have access to an audio probe? I would start at the output connection to the board and trace the audio backwards. If you get to the IC and it still doesn't sound right, try replacing the IC. Voltages look right, the Diode might cause a problem but I'm not a Diode expert. I'm not really an expert at all, I just have debugg my pedals often... Audio Probes help.

Jacob

[lazerphea]

Do you have access to an audio probe? I would start at the output connection to the board and trace the audio backwards. If you get to the IC and it still doesn't sound right, try replacing the IC. Voltages look right, the Diode might cause a problem but I'm not a Diode expert. I'm not really an expert at all, I just have debugg my pedals often... Audio Probes help.

Jacob

Thanks for the input Jason: just finished audioprobing it, and everything's fine.
I already swapped 3 4558, but noching changes.
The diode thing seems not to affect the circuit: I think that diode protects the circuit from accidental inverse polarity... I took off the diode and it's still as before...

[arma61]

I found out that I can make it distort again removing the battery a couple of times... 

Ciao

I know you've checked them many times already ...!! but this "removing the battery..." could be a sign of bad electro orientation (or a drained battery) ??

[lazerphea]

Ciao

I know you've checked them many times already ...!! but this "removing the battery..." could be a sign of bad electro orientation (or a drained battery) ??

Ciao Armando!
The battery is a brand new one, and the three electrolytic capacitors are all oriented correctly... I don't know what to do. The problem is that if I don't understand where I'm wrong, chancer are that when I'll build it for the first time, I'll make the same mistake again... :\

[lazerphea]

Here's a sample of what's goin' on...

[jkokura]

That is strange... I'm not sure what to tell you...

Jacob

[arma61]

weird!!

I'm not sure what's your problem and if this will solve it, but, looking at the schem and layout shouldn't D5 be connected only to +9 and 91R like this (unless I'm misreading your layout  )




Hope this helps

[lazerphea]

weird!!

I'm not sure what's your problem and if this will solve it, but, looking at the schem and layout shouldn't D5 be connected only to +9 and 91R like this (unless I'm misreading your layout  )



Hope this helps

You're right, Armando: yesterday, when I realized I put a 1N4148 instead of a 1N4001 I also noted this error, so I just took apart the diode, without substituting it (I don't have a 4001 right now), but nothing changed...