These are old analog bucket brigade devices, a technology developed by Panasonic Japan. They produced a range of these devices, right up to 4096 stages and with varying noise level designs.
Nice old technology and extremely difficult to find replacement BBD devices now
DO NOT confuse these with another device, also called a MN3001 from United Micro, those devices are totally unlike this BBD.
Panasonic Semiconductor
Part number: MN3001
Function: Dual 512 Stage bucket bridage device
Maximum theoretical delay with this device (using both 512 stages) is 51.2mS
Maximum clock rate is 800Khz
These were commonly designed into early Analog flangers, delays, and guitar special effect products.
The bucket brigade device contains a series of capacitor sections which pass the analog signal. The signal in each stage is passed to the following subsequent stage using transistor switchs, under control of a clock signal. The big advantage of these devices was that they do not rely on any form of A~D conversion, making the circuit design much easier than an equivalent digital processing audio flow AND these devices have very high resolution but the downside is a limited dynamic range.
Look inside your old analog effects units and it is quite possible you will find one of these.
14 pin DIL plastic package
Datasheets (64 pages of very comprehensive technical and application information) is readily available online or I can provide one (if requested)
New unused, old stock and stored in the suitable, ESD safe material.
