IRP/Knowles Audio Signal Delay 4015-2

Fancy '80s digital delay, one in, two out with integrated input limiter. From the July/August 1987 issue of DB magazine: "has better than 90dB dynamic range. 192ms in 3ms steps via thumbwheel switches. ... Transformer balanced in and out." At $2,063 new as configured this was the most expensive delay in the product directory by a wide margin. (Reverb doesn't want me linking to it here but if you google "world radio history DF-4015-2" it's the first result.)

Sounds great. Have not experimented with overdriving it but I imagine with the internal limiter and transformers, feeding it back on itself could be pretty cool. Rare enough that searching "IRP delay" just gave me zero results in current or sold listings.