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Dolby vs. pre-Dolby

This is a topic I’ve brought up a few times before but with little response. Hopefully this time someone will be interested. Many Agoners have made reference to the fact that records from the ‘50’s sound the best.
My contention is that with the advent of Dolby (created for the purpose of reducing tape hiss) in the early ‘60’s, a very audible degradation of sound ensued. This can be heard not only on LP’s but also on CDs created from analog tapes. There is an openness and seemingly unlimited space on the pre-Dolby discs that I feel is lacking on Dolbyized discs. It can be heard most markedly on orchestral recordings. Without Dolby, the full orchestra surrounds you and still there Is a great sense of detail. With Dolby a lot of the wonderful ambience is lost.
Dolby’s cutting off of the highest frequencies, although allegedly electronically replaced, eviscerates the sound and deprives us of the full picture.
Has anyone else heard this phenomenon?
rvpiano

Showing 2 responses by cleeds

cleeds
6,236 posts
 
rvpiano
I’m speaking of analog LP’s produced by record companies in the late ‘50’s and early ‘60’s whose tapes were recorded NOT USING the Dolby A process. which had not yet been invented. And those master tapes were often used in the making of modern CDS.
How would you know which original recordings from the 60s were made with Dolby 'A', and which ones were made without any NR, or were made using a competing compression/expansion system?

As the 60s evolved, multitrack recording became the norm, so that may explain the difference you hear in SQ between the decades.

In any event, none of the Dolby circuits (A, B, C, SR ...) work by "cutting off of the highest frequencies" which are then "electronically replaced."
cleeds
6,236 posts
 
rvpiano
There is an openness and seemingly unlimited space on the pre-Dolby discs that I feel is lacking on Dolbyized discs.
I've never seen a "Dolby disc," so I'm not sure what you're trying to say. If you're referring to the tape that made the disc, how would you know whether Dolby was used, or not?
Dolby’s cutting off of the highest frequencies, although allegedly electronically replaced, eviscerates the sound ...
Dolby does not cut off the highest frequencies. That's not how it works. It actually increases HF (above a certain frequency and on a sliding band) to improve S/N, then decreases HF on playback by a corresponding amount. It's a complementary compression/expansion system.

To work as intended, Dolby requires that the record deck be properly setup for bias and EQ and that the Dolby circuit be aligned to reference level. Naturally, those conditions aren't always precisely met, and that's why Dolby has a bad rep among some.
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