ACL - VC Dual Delay
Audiophile Circuits League VC Dual Delay is a specialised delay unit, designed for hours and hours of sound mangling, from pitch modulation effects to ethereal outer-galactic spaces. It's a bold statement, we know, so let's see how it does it.
VC Dual Delay features two identical independent delays, suitable for either parallel or serial operation. Sonically, we opted for the Princeton PT2399 delay chip, which is very reminiscent of the kind of analog BBD (bucket brigade device) chips used in many classic guitar delay and chorus pedals.
Each delay's rate can be controlled with CV (with an option to boost the resolution by ten times), and has its own feedback loop with high and low pass 6dB filters. These filters don't feature voltage control as they're designed to provide a natural damping effect in the feedback loop (incidentally, we chose 6dB filters, as we find this slope provides the smoothest natural damping effect). And feedback really is what these delays are all about!
One of the defining features of the VC Dual Delay are the FB IN jacks, allowing you to patch any processing effect you want to the feedback signal - an LFO-modulated filter, chorus, reverb, EQs, pitch-shifters - anything you like. In fact, one of our favourite uses is to patch one delay into the other, for example feeding the output of module one into the input of module two, then feeding the output feedback out of 2 into the feedback of input 1, creating a dense diffused space where the echoes seem to float away. You can even combine multiple Dual Delay modules, chained into one another, to create reverb-like spaces! In fact, interesting feedback crossover is only a switch away, feeding delay A back into B and vice versa.
It should be clear that the primary design concept behind Dual Delay was a delay module that works in conjunction with other modules to create out of this world effects - so much so that we deliberately left off a wet-dry balance control and normalised the audio and CV inputs of module of A to the inputs of B (to simplify multi-module patching). And after many sleepless nights of fun and forgotten meals, we're pleased to report that we consider this module very much 'mission accomplished'.