A few troubleshooting questions for a few modules.
Hey there,
I have built several modules over the last month, all of them with prepopulated SMD from Calsynth. Most of them have been built without a problem. However, I have a few that are giving me some issues.
The issues:
Hans: Output lowers in volume significantly when I turn up resonance, but resonance only really becomes noticeable when the knob is turned past 75% or more. This doesn't seem like the correct operation when compared to the demonstration video.
Singer: I love the sound of this one, but I'm only able to use the A side, putting audio into the B side does nothing. Also I'm getting low output volume from the module. My Alstaden is really loud, but it feels like its volume halved when I plug it into Singer.
Influencer: I'm sure I've located the problem with this one. When I initially plugged this one in, it overloaded my PSU on my rackbrute and caused a whole row of modules to lock up. On inspection of the board it appears that DV10 was missed entirely during the SMD population. Would that cause such a situation with power? Either way I'm going to order the part in the hopes that fixes it.
Chasing Lights: This works without issue and I really enjoy it. I used Red, Yellow and Green LEDs for lanes A, B, and C respectively. In typical fashion the green LEDs are blindingly bright. I just want to confirm that upping the resistance of RB_C is the correct change to lower the brightness. This is specifically the top row of LEDs per lane, not the active step LEDS that have a trimmer.
Any pointers or advice on these modules would be greatly appreciated! I've been really enjoying the modules I've successfully built and I'm looking forward to getting the rest in working order to add to the roster.
Thank you for such a quick reply Stefan. I really enjoy your designs. I am up to 15 of your modules at this point! I did some testing this morning and took some pictures that I will attach.
Chasing Lights
First, thank you for reassuring me about the resistor at RB_C is the one I need to modify for the running lights on my Chasing Lights. Ill experiment with some thru hole resistors I have on hand to find a resistance that lowers the brightness to a point I like and then order the appropriate SMD resistor.
Influencer
I was apprehensive about plugging this one back in, but took the chance and hooked it up. Perhaps it was a bad IDC cable connection on my initial test, as this time it worked without issue. I hooked up a few other modules on the same bus and they did not lock up this time. I will order the missing part and test again to make sure it is good to go.
Singer
Here is a scope test of Singer. A basic sine out of Alstaden. At full dry, the output is around 75-80% of the original signal, and much less at 50/50. The LFO works as intended, at least on the A side. If I flip the switch to B the LED lights up, but I get no signal at all if an oscillator is plugged in. I do get BBD chip noise oscillations out of the output when I crank feedback. My new issue is that the VCA is not working for either A or B. Putting CV into the input does not effect the incoming signal at all. I tried both an LFO and a static voltage. Perhaps that may be my B side issue, considering I can hear chip noise, but not input noise.
Hans
I do understand and expect lower output with increased resonance on filters, it is fairly common and I have others that operate similarly. That being said I still feel like it is not operating correctly. With resonance at 0 and cutoff fully clockwise my output is less than 50% of my input. I do not get subtle resonance at noon on the knob, only further lowered output. Resonance is only barely noticeable at 75% and beyond, but barely audible. In the following pictures the top sine wave is input, and the bottom green trace is the Hans output.
Again, thank you for the help! It's excellent that you take time out of your day to reply back, especially for a DIY project. If you need pictures of the boards themselves I am more than willing to do that as well, just let me know.