Analog LPs made today.

[hailteflon]

This a question for someone who is actually involved in the mastering process of today’s analog pressings of LPs.

First, I encountered many months ago a newsgroup article (not on DIYA) about the CBS Discomputer. The guy was saying that the CBS Great Performances classical remaster series were actually digital. I found this hard to believe since I had listened to them for years and was sure they were pure analog. The ambience is intact in these recordings. Digital cannot do this.

After an extended period on the web I evidently encountered the patent number for the Discomputer and downloaded it. The patent is from 1979 and is probably for the Discomputer, although it doesn’t say it. It is a CBS patent for a computerized cutting control.

The CBS diagram shows that there is no digital component in the path to the cutting head. The guy on the newsgroup was saying that many companies starting using digital delay lines between the master tape and the cutting head. I suppose that they did this at the end of the analog era, probably to avoid replacing the preview heads on a pure analog tape machine. Most LPs made after 1980 sound digital.

When the heads wore out on the pure analog machines they would use a standard tape machine with one head. The pure analog signal fed the cutting control computer and a digital delay line fed the cutter head.

My question is this: Do the original master issues that are sold today use a digital delay line for the cutting head? Or do they have tape machines with preview heads? I was told years ago that they actually obtain the original analog master from the vault. They put up a million dollar bond before they can take it with them.

The few analog remasters that I have heard were not obviously analog. Acoustic Sounds sells a lot of them, about $30 each. There must be at least 10 companies that make them. Best Regards, Mark