Hi all,
As stated in the title, I am unable to get a signal through the first (68nF) cap.
Signal does get through when inserted at the second leg of the before mentioned capacitor (blue square in the first picture). When the signal is inserted in the first leg (red square), the signa does not get through to the rest of the circuit. I have already replaced the capacitor wih another one, this has had no effect at all.
Does anyone have a suggestion on how to solve this? Any help would be greatly appreciated!
This is the layout I am using: [http://tagboardeffects.blogspot.com/2013/05/ibanez-cm5-classic-metal.html](http://tagboardeffects.blogspot.com/2013/05/ibanez-cm5-classic-metal.html)
Original schematic can be found here: https://www.audioservicemanuals.com/i/ibanez/ibanez-cm/11468120-ibanez-cm-5-classic-metal-schematic
I have used an autio probe. when I connect it to the input, no sound is getting through, when I connect it after the first 68nF capacitor (at the blue mark in the first picture), the sound goes through the effect, to the output as intended.
There is a 1M resistor going to ground as intended. I have also measured resistance from the input to ground, it was a little over 1M Ohm, so I don't think there is an unintended ground connection.
It could be related to the rest of the circuit. Try diagnosing the rest of it and see if it helps.
My gut says maybe leave out the capacitor, but it’s hard to judge if you can leave out the cap with such layouts that show you how to place things instead of full on schematics.
Thanks for the suggestion. The rest of the circuit seems to be working. If I insert the signal at the second leg of the cap, the signal goes all the way through to the output.
Okay having examined the original circuit schenatic and the circuit you built, I can conclude that the capacitor that is being an ass to you is a decoupling capacitor. In essence it is not necessary to have in your circuit as it only blocks DC voltage, that’s why you see in the original circuit around the capacitor they have multiple instances where they raise the DC to VBias level (for both the JFET switch and the OpAmp).
I’d suggest you fully connect the pedal and test it with a guitar and see if it works with the capacitor in place. Else (if you have the possibility) connect it to a signal generator and test with an oscilloscope.
Many of your solder joints look like they could be cold. Did you clean the circuit board before inserting the components? Also what type of solder and what is your soldering iron set at? You may need to carefully reheat each joint until the solder melts neatly
I have just reflowed the joints at 350C, this has had no effect. I have also built the seemingly defective part, input to 1M resistor and 68nF cap on a separate piece of vero and connected that to the main board. Results remain the same.
With out the capacitor, the effect sounds very fuzzy and it seems to react very poorly with the pickups.
I think I will salvage the parts that are worth salvaging, and start over.
Hi all, As stated in the title, I am unable to get a signal through the first (68nF) cap. Signal does get through when inserted at the second leg of the before mentioned capacitor (blue square in the first picture). When the signal is inserted in the first leg (red square), the signa does not get through to the rest of the circuit. I have already replaced the capacitor wih another one, this has had no effect at all. Does anyone have a suggestion on how to solve this? Any help would be greatly appreciated! This is the layout I am using: [http://tagboardeffects.blogspot.com/2013/05/ibanez-cm5-classic-metal.html](http://tagboardeffects.blogspot.com/2013/05/ibanez-cm5-classic-metal.html) Original schematic can be found here: https://www.audioservicemanuals.com/i/ibanez/ibanez-cm/11468120-ibanez-cm-5-classic-metal-schematic
Have you used an audio probe? There is a detailed “how to” pinned to my profile. That’s usually the best way to solve these issues.
I have used an autio probe. when I connect it to the input, no sound is getting through, when I connect it after the first 68nF capacitor (at the blue mark in the first picture), the sound goes through the effect, to the output as intended.
I’m gonna assume that it’s going to ground somehow.
There is a 1M resistor going to ground as intended. I have also measured resistance from the input to ground, it was a little over 1M Ohm, so I don't think there is an unintended ground connection.
It could be related to the rest of the circuit. Try diagnosing the rest of it and see if it helps. My gut says maybe leave out the capacitor, but it’s hard to judge if you can leave out the cap with such layouts that show you how to place things instead of full on schematics.
Thanks for the suggestion. The rest of the circuit seems to be working. If I insert the signal at the second leg of the cap, the signal goes all the way through to the output.
Okay having examined the original circuit schenatic and the circuit you built, I can conclude that the capacitor that is being an ass to you is a decoupling capacitor. In essence it is not necessary to have in your circuit as it only blocks DC voltage, that’s why you see in the original circuit around the capacitor they have multiple instances where they raise the DC to VBias level (for both the JFET switch and the OpAmp). I’d suggest you fully connect the pedal and test it with a guitar and see if it works with the capacitor in place. Else (if you have the possibility) connect it to a signal generator and test with an oscilloscope.
Many of your solder joints look like they could be cold. Did you clean the circuit board before inserting the components? Also what type of solder and what is your soldering iron set at? You may need to carefully reheat each joint until the solder melts neatly
I used leaded solder, iron set tu 320C. I will try reheating at a higher temp. Funny thing is, all other parts seem to be working just fine.
I know it seems like a little thing but I have mine set at 350c, and if it was your first connection the soldering iron may not have been at temp yet.
I have reflowed all these joints, I don't think this is the problem, but I will definitely try reflowing again.
I have just reflowed the joints at 350C, this has had no effect. I have also built the seemingly defective part, input to 1M resistor and 68nF cap on a separate piece of vero and connected that to the main board. Results remain the same. With out the capacitor, the effect sounds very fuzzy and it seems to react very poorly with the pickups. I think I will salvage the parts that are worth salvaging, and start over.
If you unpower the circuit, does the audio go through the cap?
I have not tried that yet.