I just finished building the Tonepad Orange Squeezer project on one of Tonepad's PCBs. The LED works, I've checked the switch to make sure it is working, but I am getting no sound when the effect is on. I replaced the electrolytic caps with tantalum caps of the same value, and am using the TI RC4558 chip. Everything else is ecactly what the project requires. Could someone help me debug this? I'm still new to this and not very experienced with testing the circuits so I don't know what I am looking for.
http://www.tonepad.com/getFile.asp?id=88
gentle bump, cause I'm having the same issues.
I might suggest Gators81, that you provide more details as outlined in the Debugging sticky to get more help.
Hi
the OS can be tricky to set up. The bias trimpot needs to be set just right. Too little and you get no compression, too much and you get no signal.
What type of JFETs did you use? Check that the gates are 2 to 4 volts lower than the source.
cheers
Finnaly got around to testing the circuit. Here are the readings I took:
9V power Supply - 9.07
Q1 - Gate: 2.3
Source: 3.98
Drain: 9.07
Q2 - Gate: 0.8
Source: 3.1
Drain: 1.35
IC1 - Pin 1: 8.6
Pin 2: 8.6
Pin 3: 0
Pin 4: 0
Pin 5: .02
Pin 6: 8.3
Pin 7: 6.0
Pin 8: 9.1
I used the TI RC 4558 for the IC in an IC socket and replaced the 4.7mF Electrolytic caps with 4.7mF Tantalum caps. I used a 1N34A diode insted of the 1N100, because I couldn't locate any. The parts list for the Tonepad kit gave a choice of the two. The sustain pot is a 10k trim mounted on the PCB and the level pot is 10k in the box for external control.
Again, the problem I am having is no sound with the pedal on. I've tried to adjust the sustain trim pot EXTREMELY slow with no luck with the level knob at full.
Any recomendations would be much appreciated.
???
I referred to the GGG instructions for their version of the OSQ and noticed that pins 5,6,7 and 8 on my IC are different than the values listed there. Maybe this could be my issue......
Here is the link to the GGG OSQ instructions (page 3) I referred to when testing the circuit:
http://www.generalguitargadgets.com/pdf/ggg_osq_instruct.pdf?phpMyAdmin=4a28f86a515b7883e7bc35a68d4e7b6d
I'm not the best at debugging, but I have built an Orange Squeezer.
Pin 5,6,7 is definitely not right. I believe pin 5's voltage is set mainly by a voltage divider created by the 390K resistor and one of the 470K resistors.
I would check in that area for solder bridges or incorrect component values. :)
Mike