CONTEST Happy New Years Limited Parts Contest

CONTEST
The limited information raises more questions than answers, unfortunately. No one seems to know the transistor part numbers. No one has measured and published the node voltages. The C5 connection is highly suspect. I think we have wandered too far off-topic for this thread.
 
I made a couple changes to my project. I need to update the schematic.

A few months ago I tried adding a Zen drive type Voice control to a Bluesbreaker circuit on my breadboard. I tinkered away with some different values for the pot, cap, and resistor, but never found a combination that had a big enough sweet spot for me. The way it worked just messed with the amount of gain too much for a circuit whose gain pot changed two op amps in tandem.

So on this circuit I tried a cap blend like the Timmy with the idea that it wouldn't effect the amount of gain as much. It still did enough that I wasn't happy with the sweep. You really just can't get around the fact that letting more low end into an amplifier will lead to more distortion as it's turned up. And when you have one pot changing the gain of two separate amplification stages in tandem it makes it more finicky to dial in. So I decided to put replace the Body control with a switch to go between a tighter higher gain optino and a warmer lower gain option on U1.

Initially I went with a 4.7k/47nf for a 720hz high pass filter like a tube screamer on the low gain side. For the higher gain side I went with 2.2k and 68nf for a 1khz or so high pass filter and a little over double the available gain. I wanted to make the higher gain option tighter on the low end so it didn't flub out and the lower gain option would be a little warmer. Using the same tone control values and the same 470k/100pf combo in U2 lead to the high gain option being a little too brittle sounding to me.

I put a 2.2k/100nf combo in the high gain (720hz LPF) side to warm it up a bit. Since the high gain side now had the same LPF frequency as the low gain the tone knob sweep was a little more dialed in. To differentiate the two options further I made the low gain side even lower gain, but maintained the 720hz LPF with 10k/22nf combination. So now in U1 the high gain side is 4.5 to 50 (+1) and the low gain side is 1 to 11 (+1). Then U2 has a gain from 7.8 to 47.

I had a 1uf cap between U2 and the 1k into the clipping diodes. The clipping diodes were going to ground. So I decided to eliminate the 1uf cap and send the clipping diodes to the 4.5v bias voltage. This did not work lol. It started sounding like a damned tremolo. I guess the DC was getting in. So I put the cap back.

Also I put a 1k/1nf rc filter in front of the first op amp stage to protect the input of the op amp and filter out some noise like a Rat. I could probably up the 1nf to 10nf to bring the filter down a little or even just remove it altogether. I think some op amps have input protection and some don't?
 
The way you have it, the IR diode is reversed biased. It never conducts. Try removing it and see what happens. It appears that Q1 is leakage-biased in your circuit.
Can you measure and report the voltages on Q1-C, Q1-E & Q2-C?
 
Here's my last one.

I had an idea to do a take on a Jordan Boss Tone. Then I realized I was completely wrong. It's a take on the Mosrite FUZZrite. I wanted to swap out the BJTs for JFETS, but wasn't happy with the result. My goal with this build was to experiment with JFETs and tone controls. Looking at the schematic below I'm not good with either yet. Practice makes perfect I guess.

I grabbed a PF5102 at first since I don't think I've ever used one and it was sitting in my stash. The other alternative that works well is 2N5457 on my breadboard.

I wanted to try out the Stupidly Wonderful Tone Control and its various forms. In this circuit It either made the circuit too boomy or was way too subtle for my taste. For the record I tried 4 different iterations of the tone stack, but ended up on just a simple treble cut.

This is a JFET into a Bazz Fuss (blendable) into a treble control into a SHO recovery stage. I had to mess around with the bypass gain cap and R3 to get both signals pretty close in volume with one another.

One comment on the BLEND control. I originally had a B250k. While this cut out each signal entirely on either extreme of the control, there was too much volume drop in between. Using the 100k helps with that, but now I've got juuuuuuuust a small about of bleedthrough on each extreme. I'm ok with that. Why? Well, It's my damned circuit!!! lol

So, what does it sound like? With my humbuckers, you can go from a slight dirty boost all the way to fuzz territory depending on the BLEND control and the guitar's volume knob. On bass, this is pretty sweet going from clean to fuzz and everywhere in between.

I'm pretty pleased with this one.

I call this one the "TONE GRINDER".

Enjoy!

BuddytheReow
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