Yes: Producer Brian Kehew talks about restoring the tapes for the 14CD Progeny live set.

Listen to PROGENY with producer Brian Kehew: Part 1of 9

"After a day or so of trying to mix from poor sound, it became clear to us that the Dolby units (used to reduce tape hiss) had been misaligned during the original recordings, and this had resulted in a murkiness. By calibrating each track’s Dolby setting (for guitar, snare drum, vocal etc.) by ear, it was possible to clarify every recorded part. And each show needed a different setting since they had all been done incorrectly. With this adjustment, we were able to restore the tracks to their original clarity and power, something that had been lost even during the original Yessongs mixing. As a result, these recordings now sound open and immediate, giving us some of the best-sounding performances of the band during their heyday.
Still, there were other problems—besides the Dolby issues (which also caused the thin sound on the Tormato album) – that had to be resolved before we could use these shows as sources.
For example, Chris Squire’s bass tone: It has always been unique and defining, and in some ways the key component to the band’s sound. But this was not captured on tape, probably because the recording equipment had been improperly set up at almost every show. At times, the bass track sounds too distorted, with no low end (the critical feature for his instrument!). It was also recorded with a single microphone that might have been poorly placed, with no “direct” sound, which is a separate channel used to give fullness and presence. Sadly, on the treble/top, the bass was also missing the distinctive stringy snap and sizzle of the famous Squire Rickenbacker. And at one show, the bass was mixed accidentally with the piano track, making it very difficult to place in the mix.
Clearly, if there was one thing on these tracks that needed improvement, it was the bass recording. So many “tricks” were used to make the bass sound fuller and stronger—sometimes with excellent results. In addition to special EQ and compression, the bass channel was rerecorded through an old 1970s bass amplifier and speaker to get a true low end. This now-deep tone was added to the rather thinly recorded bass sound to create a full and sharp tone. The technique worked so well that it was also used on the thin kick drum track, which the bass amp filled out nicely."
— PROGENY producer, Brian Kehew