Disc 1&2 Matrix Sources
AUD - ext. mic>Tandberg mono R2R @ 7 1/2ips-reelm>VHS1>MATRIX Remaster
SBD - unconfirmed low gen very clean analog>DAT1>MATRIX Remaster
Disc 3
AUD - cass4>DAT2>PCM>Remaster
Matrix - 80/20 SBD/AUD mixed with Samplitude.
Best way to describe the sound - AUD source gave the SBD natural reverb and added Harmonics.