About

A follow-up for the lags from the lags+comps FOXYSTEM module, this module also serves two lag processors for electric signals. Like the FOX04C, the lag action is to 'smooth out' the change in the input voltage, instead of instantly jumping to its new value - slide to it within a set time. However, unlike the FOX04C lags, the two FOX06C has are extended in many ways.

Firstly, there are two inputs, and they are both attenuated. The inputs are mixed together for lag processing. Input 2 has a handy attenuverter, allowing for more flexible control of the input signal in the mix. The speed settings are separated into rise and fall control, each with a dedicated attenuated CV input. The range goes from upper-mid audio frequencies to slow modulation frequencies. The 'both' input allows for simultaneous, almost-exponential voltage control of rise and fall on top of their initial settings. It won't bring the speed much higher if rise and fall are already maxed out, however, it's possible to bring the speeds way lower than the lowest rise/fall settings using the both cv in, as well as freely operate within the range of rise/fall knobs. Finally, both halves have an output, augmented with a bicolor LED indicating its state, and a loop output that, if patched back into one of the inputs and positively added to the mix with the knob, causes the unit to oscillate. A handy switch does this for you without the need for a patch cable, however, it's possible to use the patched version to control the looping effect with an external gate using a multiplier or any other kind of logic AND functiion.

This module is an extremely versatile device. It can be a glide/glissando processor, an attack-release envelope and a voltage-controlled LFO - these functions are quite on its surface. However, there is much more to the lag processors, as one can as well be a filter with or without an emphasis peak, depending on the loop switch, a voltage mixer, a bad sample-and-hold, and much more!

Schematic

The schematic is almost a full recreation of my own Dual VC Lag Processor of the SFP series, so for the detailed explanations, please, visit the link. The circuit was mildly updated in order to have better and more suitable functionality.

The input section, that previously directly took an input to IC1B, now has its own dedicated double-inverting summation stage (IC3B/C). This is because it's impossible to realise two attenuated inputs and the looping functionality by just passively summing them at IC1B. In addition to that, the second input has now an attenuverter built around IC3D. In future, one op-amp can be made free by altering this input stage, while also making input 1 also attenuverted. However, i am sharing the concept version here, and am showing exactly what i did with it, so this mod remains for the future.

Another difference is the output LED driver. If i were to drive a bicolor LED directly from IC1C, it would cause a significant signal drop at the output jack - that's why i am using a dedicated op-amp driver. It uses two op-amps in order to more precisely drive the bicolor LED that depicts the output voltage. In retrospect, maybe, unlike the summators module, this module can do without a precise driver, thus freeing up another op-amp.

Everything about this design follows SFP32 quite closely, bar a few resistor values changed for a more even BOM without affecting the action itself. The updated input stage is the main update for this version, and a very important one, as it opens up the sheer entirety of possible usages of this unit in audio-aimed feedback-including configurations, among many other interesting things.

Pictures