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Dragonbeard

Started by danfrank, May 12, 2020, 04:25:20 AM

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danfrank

Finished this one also, I still need to test it out...
I managed to put the 4 LEDs at the same spacing as the rotary switch positions. I did have to turn the middle pot around 180 degrees so the 4 LEDs could fit. The 9mm pot was because when I ordered them I was stuck on stupid and didn't order the correct size to fit on the PCB.
I originally had the super mojo 308 cans installed but thought the tab on the cans designated pin 1... Wrong! I had to cut them out and then order some pedestrian dip-8 versions to use. I bet it'll sound as good though! Lol!

danfrank

#1
The front side. Making those 4 LED holes relatively even was super hard. I'll use a compass next time.

I do have a question on this project... Shouldn't R7 (crunch) be 370 ohm, R8 (overdrive) be 560 ohm, and R9 (distortion) be 1K1 ohm? I always thought that the larger the resistance around an op amp the higher it sets the gain, or am I misguided on this?

And, yes, I just realized that I have the 4 settings on mine the opposite of what they should be. Doh!


madbean

#2
I can understand how the rotary positions might be confusing.

The order I have should match what's on the back of an actual Expandora (the internal DIP settings):
OD is the 560R
Distortion is the 1k1
Crunch is the two resistors in parallel (on the Dragonbeard it's a single 370R resistor instead of the 1k1 and 560R in parallel)
Forbidden is no resistors

You can certainly re-arrange them in increasing resistance if you like so the effect increases in gain going CW.


madbean

#3
Well to put a finer point on it the labels in the doc are right for the resistors but not in the same order as shown on the back of the pedal. So yeah that is a bit of a goof on my part. I can make a note of that.

danfrank

#4
Ok, got it. My mistake was assuming it went "Crunch, OD, Dist, Forbidden" on the Dragonbeard.
Oops!