eh là bas ma
Well-known member
Hello, this is my second troubleshooting post on this circuit : i thought it was ok, but it's not compared to other builds.
The obvious issue is that on my build it is much harder to dial some good modulation settings, compared to other builds.
Manual control works but it is weirdly calibrated, with modulation only in the last quarter of its rotation. Here, the tiniest variation has a huge impact on the modulation, making it almost impossible to fine-tune. However, comparing with audio samples from other Xenotron builders, my circuit is able to achieve some similar sounds.
It's probably quite close to be fully working. Besides Manual, all other controls are effective.
I can hear something like a delay being modified when i turn the Manual pot within the last quarter of its rotation. The only difference is that it's seems harder to dial the settings on my build, something is wrong somewhere : Manual, and maybe also Depth, aren't responding as they should, compared to other builds. Other Xenotron builds have some modulation during most of the Manual rotation. Manual at noon, their circuits are flanging, not mine.
The BBD trimmer doesn't allow me to get a modulation through the whole Manual rotation. Although, I think the BBD is working, the modulation appears between 11' and 3 o'clock on the trimmer.
Once i have calibrated the circuit as much as i can, the only way to hear a faint modulated sound with Manual at noon, is by turning up the Feedback to extreme values, this way i can hear some feedback noise at one end of the sweep, but not the sweep itself. It sounds more like a cyclic noise than a modulated signal.
Another lead is the distortion appearing in the first half of the manual rotation, when i use the Time output (wet only). If i understood correctly, there isn't any distortion like this on the other builds, so it could be a big sign pointing in the direction of the issue.
However, this distortion isn't really an issue because there isn't any modulation in the distorted aeras. It's possible to calibrate the BBD so that there isn't any noticeable distortion in the last quarter of Manual rotation, where the modulation works. I only mention it as a potential clue.
The signal is getting more and more distorted as i turn the Manual pot CCW. Distortion disappears around noon, the signal cleans up progressively, and the modulation appears around the last quarter of rotation.
Any idea about what could cause this distortion ?
Calibration instructions do mention some potential distortion, supposed to be dialed out thanks to the BBD trimmer. But no matter where i set the trimmer in its usable range, between 11 and 3 o'clock, i can't get some modulation in the first 3 quarters of the Manual pot. Listening to the wet signal only, there is always some distortion in the first half of the Manual rotation.
The trimmer can help eliminate the distortion if i use the Mono output : the clean/wet ratio makes it much less noticeable than when it's wet only.
But that's all, it's still there if i use the "wet only" Time output.
About the crossed wires : i soldered the 3PDT pcb upside down and had to adjust the wiring.
Maybe i didn't take everything under consideration, even if i managed to correctly wire this footswitch board to the main pcb, and something is still wrong because it's upside down ?
If the first 3/4 of the Manual rotation are useless, maybe the quick fix would be to add a resistor and use an other pot with a smaller value, corresponding to the effective aera on my current Manual pot, so a 75k resistor and a 25k pot ?
How would you proceed, if you only wanted the second half of the Manual pot's rotation ?
I tried to add a 100k resistor across the Manual outter legs, hoping to get this second half, but it just suppressed the modulation through the whole rotation...
Every observation and suggestions are welcome !
The obvious issue is that on my build it is much harder to dial some good modulation settings, compared to other builds.
Manual control works but it is weirdly calibrated, with modulation only in the last quarter of its rotation. Here, the tiniest variation has a huge impact on the modulation, making it almost impossible to fine-tune. However, comparing with audio samples from other Xenotron builders, my circuit is able to achieve some similar sounds.
It's probably quite close to be fully working. Besides Manual, all other controls are effective.
I can hear something like a delay being modified when i turn the Manual pot within the last quarter of its rotation. The only difference is that it's seems harder to dial the settings on my build, something is wrong somewhere : Manual, and maybe also Depth, aren't responding as they should, compared to other builds. Other Xenotron builds have some modulation during most of the Manual rotation. Manual at noon, their circuits are flanging, not mine.
The BBD trimmer doesn't allow me to get a modulation through the whole Manual rotation. Although, I think the BBD is working, the modulation appears between 11' and 3 o'clock on the trimmer.
Once i have calibrated the circuit as much as i can, the only way to hear a faint modulated sound with Manual at noon, is by turning up the Feedback to extreme values, this way i can hear some feedback noise at one end of the sweep, but not the sweep itself. It sounds more like a cyclic noise than a modulated signal.
Another lead is the distortion appearing in the first half of the manual rotation, when i use the Time output (wet only). If i understood correctly, there isn't any distortion like this on the other builds, so it could be a big sign pointing in the direction of the issue.
However, this distortion isn't really an issue because there isn't any modulation in the distorted aeras. It's possible to calibrate the BBD so that there isn't any noticeable distortion in the last quarter of Manual rotation, where the modulation works. I only mention it as a potential clue.
The signal is getting more and more distorted as i turn the Manual pot CCW. Distortion disappears around noon, the signal cleans up progressively, and the modulation appears around the last quarter of rotation.
Any idea about what could cause this distortion ?
Calibration instructions do mention some potential distortion, supposed to be dialed out thanks to the BBD trimmer. But no matter where i set the trimmer in its usable range, between 11 and 3 o'clock, i can't get some modulation in the first 3 quarters of the Manual pot. Listening to the wet signal only, there is always some distortion in the first half of the Manual rotation.
The trimmer can help eliminate the distortion if i use the Mono output : the clean/wet ratio makes it much less noticeable than when it's wet only.
But that's all, it's still there if i use the "wet only" Time output.
About the crossed wires : i soldered the 3PDT pcb upside down and had to adjust the wiring.
Maybe i didn't take everything under consideration, even if i managed to correctly wire this footswitch board to the main pcb, and something is still wrong because it's upside down ?
If the first 3/4 of the Manual rotation are useless, maybe the quick fix would be to add a resistor and use an other pot with a smaller value, corresponding to the effective aera on my current Manual pot, so a 75k resistor and a 25k pot ?
How would you proceed, if you only wanted the second half of the Manual pot's rotation ?
I tried to add a 100k resistor across the Manual outter legs, hoping to get this second half, but it just suppressed the modulation through the whole rotation...
Every observation and suggestions are welcome !
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Instill have to order an LED according to the specs of the one from the documentation.
