I had breadboarded circuits before and decided to build a sort of pedal/circuit prototype creation that would make it easier, especially when building pedals, to breadboard circuits. All it is is a piece of wood that I attached three panels of acrylic to three sides of the wood. I will make another entry showing what I'm talking about by itself. Anyways, it took me about 5 or 6 attempts to get the circuit working on the breadboard. I was unfamiliar with orientating transistors, specifically non-PNPs, and am pretty sure that my mistake every time until I got it working was that I had transistors in the wrong way. Although it didn't sound good, and something seemed off, I did get it working. Below is a picture of the working circuit on my breadboard prototype thing.
This was before I added the LED indicator. I just wanted to get the audio working at first. I then wired in the LED and noticed some problems. The LED worked and responded to my turning of the speed knob but once I maxed out the speed and tried to decrease it the LED stayed on and did not start blinking. The depth pot also seemed to have no impact on the sound when turned. Luckily the first thing I thought of was the problem. As seen in the picture I was using a 9v battery to power my circuit. I had used this battery many times before and questioned how well it was performing after all this time. First I measured the DC bias on Q4 to assure that I was getting close to 4.5V. I was not. The voltage over both 1M resistors that connect to Q4's gate were well short of 4.5V. I then measured the battery's voltage and got something around 5.6V. Not good. So after swapping out the old battery with a fresh 9V, I remeasured and tested and everything was sounding great. The LED was responsive to all of my changes in speed and the effect of the depth knob was very apparent. Excited, I went and got the PCB to start wiring everything into place.
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