The Really Nice Levelling Amplifier (RNLA) is a compressor, of sorts, with a character that works well with vocals, bass guitar, acoustic guitars and two-mix sources. A friend describes the RNLA's tone as "thick and gooey". Some very well-outfitted RNLA users report that even with a full complement of expensive, vintage levelling amps/compressors, the RNLA still fills a niche that the others don't!
The sonic performance of the RNLA harkens back to the Really Nice Compressor's (RNC's) origins.
The original RNC was, in fact, based upon an optical gain element that was ultimately rejected (and tucked away) due to its imparting of a sonic signature (i.e., "color"). However, just like trying to throw away a ball of adhesive tape, this one has also stuck with (to?) us! What's the old saying? What's old, is new again? The implementation is a little different (i.e., no opto) from the 1984 version, but the final sound is eerily similar...