Two of my latest modules from this holiday’s building spree:
- The “AC & DC” mixer, with four channels. Each channel input sensitivity can be switched between Eurorack level (unity gain with knob at max, DC coupled) and Line level (4x gain when with knob at max, AC coupled), so I can mix in my other synths together with my oscillators, for instance. There’s also a switcheable clipping circuit that will apply 3v9 zener diodes to the first OpAmp stage and boost the gain by 2x to bring output back to +5V/-5V levels. I quite like how the clipping affects the beating effect when several oscillators are loosely tuned together. I can also nicely crunch some drums with it.
- A “Multiverter” utility module, comprising two attenuverters with center detent and a switched multiple for great versatility. I realized after the build that the matching of the OpAmp gain transistors together with the two halves of the pot is key to achieve actual “zero” gain when the pot is at the center detent. I’m planning a version 2.0 of the main PCB where I add a trimpot to adjust that to near perfection. I also want the module to output an adjustable +5 to -5V DC offset when the attenuverter input is not in use. This way I could for example tune two oscillators by rotating one knob only.
