I recently acquired an early 80s (1982 on the MOBO) Audio Digital TC2 digital delay from a parts pile/junk heap, and after replacing the corroded power cable was delighted to hear it work. Roughly one second at 12 bit 30khz near as I can figure. Here's a peek at the business section of the front panel, rather standard delay range switching to the right of what has to be the coolest delay modulation section I've encountered, it'll either operate on a garden variety onboard LFO for standard flange, or you can set the delay speed (playback pitch) to follow the pitch at the audio input.
Let's have a peek inside and bask in the glory of what once was the manufacturing norm, through hole technology:
..use of metal can transistors, mica capacitors, 5% tolerance resistors..
..and socketed DIP package RAM.
Mitsubishi M5K4164, a 65,536 bit dynamic RAM chip, six in all here... see gutshot of this part
Not a sign of SMT in this device, which is somewhat refreshing in the 21st century. (This is coming from a guy who uses 20th century tools to work on 21st century stuff, which often keeps my sailor vocabulary well polished, which in and of itself isn't so bad either...)