The Red Sector A delay started off as result of the demand for an analog delay with an increased delaytime over the standard single MN3x05 chip delays around. Now, that's not really anything new since there's plenty of analog delays around with these "longer" delaytimes but none of my own hand. Other than that I aquired quite a handfull of the Coolaudio V3205 chips and thought of making the application an experiment as well.
Conservative breed as we, guitarists, are, the older stuff is always better. Therefore when the Coolaudio BBD chips became available a while ago the first response was that these were way poorer sounding and noisier than the original Panasonic MN3205's. When thinking of the usual applications using these chips there's usually a compander as well as drastic filtering around the BBD's. If the chips were poor sounding that implies distortion which suggests ether the chip cannot be set up right (among other things due to it's biasing) or were, in the applications in which they were tested, not set up right in the first place. Regarding the acclaimed noise one can womder how the noise from these chips is so prominently more than for their Panasonic counterparts if there's such an extreme filtering at the output of the chips. Time to put some of the claims of the Coolaudio chips to the test.
The use of low noise components makes the Red Sector A already a low noise device. No clearly audible noise that would be caused by the BBD's was heard. Also, there was no clear audible difference heard when replacing the Coolaudio's by their "real" Panasonic counterparts. As for distortion, the use of a dual BBD system means that both BBD's need to be setup. A special (and published in public domain) "BBD probe" was developed to be able to set both stages up to absolute minimal distortion.
Analog delays are not hi-fi. Due to the limited bandwith of the delayline there's little high frequencies in the delayed signal. This is wat is considered as the "warm" sonic character of the delay but, more important, what is used to subconciously determine by ear, while performing, the difference between the dry sound and the delays. This means that the integrity dry signal should not be corrupted. Special care was taken to keep the dry signal as clean as possible of both harmonic and phase distortion.
Last but not least, the Red Sector A is not the next implementation of a public domain DIY project, as well that it has a completely custom PCB design.