Re: Ampex Quad scanning
Yes, that's quite correct, I was keeping it to the basic theory. In practice the switching point was a bit imprecise (especially with earlier machines) and visible switching can often be seen on archive recordings. Precisely switching things on a head wheel running at 15,000 rpm with the technology of the day was pretty demanding.
Odd that this has just come up! I'm currently doing a 2" Quad transfer as a favour for somebody at the moment (RCA TR70B) and I'm seeing head switch artefacts which the head switch delay timing pot won't remove. It's a Fuji tape and in very good condition (no sticky-shed at all - wonderful). Otherwise it's all good. Yes, my machine appears to be working fine on other known-good tapes, including colour bars. Bad recording, I think.
Cheers,
Paul M
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