This is the Coolaudio clone of the original MN3208 delayline. It can produce delays between 100 msecs (10KHz clock) and 2 msecs (500KHz clock).
This BBD length gives improved performance in chorus circuits over the usual 1024-stage delays, since the clock can be run at higher frequency giving better bandwidth and more clock attenuation by the filtering. A 50KHz-to-250KHz range covers classic chorus delay territory of 20msec to 4msecs, whilst allowing a bandwidth of at least 15KHz. Allowing more high-end gives a chorus more “shimmer”.