The cover art of Cream's Wheels of Fire, dimmed, beside a dark disc of concentric rings, one for each release of "White Room" measured, from period LPs at the center to the 2026 box set at the edge; each ring glows at its left–right phase difference, near 0 or −90 degrees.

Where Did the 90 Degrees Go? Haeco-CSG in Cream’s Wheels of Fire, from the 1968 LPs to the 2026 De-CSG

Cream’s Wheels of Fire came out in a 2026 Super Deluxe Edition billed as including a version without CSG. So how did CSG survive in the CDs, SACDs, and downloads that came before? I measured nine digital releases and five period LPs. Two questions came out of it, and I could answer only one.

How Records Were/Are Manufactured (4)

廉価盤でよく見かける「インジェクションモールド」「スチレン製」の LP の歴史について、改めて過去の記事や文献を調べてみました(第4弾)。生産速度爆上がり、初期投資は高価だが中長期的にペイできる、と謳われた射出成形スチレン盤が、45回転盤以外ではなかなか普及しない様子を業界誌の記事で追いました。