falco_femoralis
Well-known member
Hi all, today I build an Abyss. Spoiler: the LFO has issues
Marking out the layout. I'm doing a horizontal build for this one
Here is some of the wiring. I off boarded 3 of the pots. The RGB wires you can see here are for the top center pot. They go around and underneath to its position between the Rate and Throb pots, which are mounted to the PCB. The board is mounted slightly off center, which I did to fit the footswitch. I accomplished this by mounting the rate and throb pots into the enclosure, then feeding their legs into the solder pads on the pcb, then working the pcb over such that it bent the pots' legs in just the right way. After that I solder it up.
The wiring is done. I snuck the footswitch wires under the board. I tried to hide as much wiring as I could, the ground wire being the exception
Love to see it
And it's finished!
I have to redo the enclosure due to my misunderstanding of how space works. This isn't good enough to be a keeper, and it's certainly not good enough to sell. Also, the LFO isn't working. I used two layers of painter's tape on the bottom of the rate pot, which I'll have to revisit.
Outside of that, it came out great! My pedalboard is optimized for these horizontal pedals so I like doing them. I wish the indicator LED pulsed with the LFO, but that's ok. Maybe I can figure out how to work that out.
Edit - I swapped the painter's tape on the back of the rate pot for a trimmed up pot insulator, and the LFO has the same issues. I spent some time with the back of the pedal off watching and listening
The Voice control changes the brightness of the LFO led. It ranges from full CCW making the LED flash between off and dim, to full CW making the led flash from super bright to not as bright. The amplitude difference between the two phases of the LED seems to remain the same, it's just that its center point is moved up or down in brightness according to the Voice control. This in turn affects the resistances of the LDR's and changes the way they filter the circuit.
The Intensity control (Depth on my pedal bc there wasn't room to write Intensity) is interesting. It controls the max brightness of the LED, but it's doing some weird stuff with mine. If the intensity knob is centered, I can make the Rate control as fast or as slow as I want it and the LFO will not stall. If the Intensity control is full CCW or full CW, the LFO will slow to a stop IF the Rate control is set low. Changing the Voice control does not affect this.
If the LFO stalls out and I return the Intensity control to centered, it will eventually start again without changing the rate control, however, maxing the rate to full CW does speed this process up. So the LFO issue seems to be related to both the Rate and Intensity controls, but not the Voice, which is important because all 3 are part of the LFO circuit.
If I center the Intensity control then the pedal works ok. But I like to max the intensity on my vibes so this isn't going to work for me as is.
After looking over the diagram, I think there is an issue with one or more of the capacitors charging in the LFO circuit. I don't know as much about EE stuff as I'd like so I'm going to have to try stuff and see what happens. I wonder if the polarity of C11 is correct. It's positive side is facing the VCC, but R21 may be interfering with this? I really don't know. Being that it's only a 1uF, I'm going to swap it with a film cap. While I'm at it I may as well do the same for C12 and C13, since they are the same value. If this doesn't work I'll have to do some big learning.
Marking out the layout. I'm doing a horizontal build for this one
Here is some of the wiring. I off boarded 3 of the pots. The RGB wires you can see here are for the top center pot. They go around and underneath to its position between the Rate and Throb pots, which are mounted to the PCB. The board is mounted slightly off center, which I did to fit the footswitch. I accomplished this by mounting the rate and throb pots into the enclosure, then feeding their legs into the solder pads on the pcb, then working the pcb over such that it bent the pots' legs in just the right way. After that I solder it up.
The wiring is done. I snuck the footswitch wires under the board. I tried to hide as much wiring as I could, the ground wire being the exception
Love to see it
And it's finished!
I have to redo the enclosure due to my misunderstanding of how space works. This isn't good enough to be a keeper, and it's certainly not good enough to sell. Also, the LFO isn't working. I used two layers of painter's tape on the bottom of the rate pot, which I'll have to revisit.
Outside of that, it came out great! My pedalboard is optimized for these horizontal pedals so I like doing them. I wish the indicator LED pulsed with the LFO, but that's ok. Maybe I can figure out how to work that out.
Edit - I swapped the painter's tape on the back of the rate pot for a trimmed up pot insulator, and the LFO has the same issues. I spent some time with the back of the pedal off watching and listening
The Voice control changes the brightness of the LFO led. It ranges from full CCW making the LED flash between off and dim, to full CW making the led flash from super bright to not as bright. The amplitude difference between the two phases of the LED seems to remain the same, it's just that its center point is moved up or down in brightness according to the Voice control. This in turn affects the resistances of the LDR's and changes the way they filter the circuit.
The Intensity control (Depth on my pedal bc there wasn't room to write Intensity) is interesting. It controls the max brightness of the LED, but it's doing some weird stuff with mine. If the intensity knob is centered, I can make the Rate control as fast or as slow as I want it and the LFO will not stall. If the Intensity control is full CCW or full CW, the LFO will slow to a stop IF the Rate control is set low. Changing the Voice control does not affect this.
If the LFO stalls out and I return the Intensity control to centered, it will eventually start again without changing the rate control, however, maxing the rate to full CW does speed this process up. So the LFO issue seems to be related to both the Rate and Intensity controls, but not the Voice, which is important because all 3 are part of the LFO circuit.
If I center the Intensity control then the pedal works ok. But I like to max the intensity on my vibes so this isn't going to work for me as is.
After looking over the diagram, I think there is an issue with one or more of the capacitors charging in the LFO circuit. I don't know as much about EE stuff as I'd like so I'm going to have to try stuff and see what happens. I wonder if the polarity of C11 is correct. It's positive side is facing the VCC, but R21 may be interfering with this? I really don't know. Being that it's only a 1uF, I'm going to swap it with a film cap. While I'm at it I may as well do the same for C12 and C13, since they are the same value. If this doesn't work I'll have to do some big learning.
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