Looking forward to reading the book. I heard a rumor that the Bob Marley tracks came out of the Helios and the through 2 LA2As, and then into a revox B77 at 7.5 ips, which is unusual. Is this true?
Also, do you have any experience with the reissue Helios 500 preamps/eq?
All possible - but we always recorded to 15ips - took until the late 1970's/80's to mix or record at 30 ips. We got 8 track 1" tapes that we copied to 16 track 2" tapes and overdubbed. Mixed to a 1/4" machine at 15ips (Philips and Ampex). At Basing Street we had Urei 1176 but I'm sure at St. Peters Sq. could have been LA2's. I only know the Helios desks from the Island Studios 70-76, /Ramport, Island and Stones Mobiles, plus Helioscentric.