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NATRB, RIAA, Ffrr, FM de-emphasis curves etc.

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Bob Scott

New Member
NARTB, RIAA, Ffrr, FM de-emphasis curves etc.

Would anyone have links to (obsolete) standards, in particular industry standard preemphasis/deemphasis curves for vinyl and tape recording.

I already have the RIAA curve. I would like to know what the last deemphasis standards were for tape recording at various speeds from 15/16 ips to 15 ips, mono and/or stereo including compact cassete. Each speed had its own response curve.

I know FM deemphasis is 75uS (2122 Hz) in North America and 50uS (3183 Hz) in Europe. How about UK? Also, amateur radio FM transmissions also use pre/deemphasis. Does anyone know that/those standard(s)? Or a link?

I am also interested in FFRR deemphasis curve for older 33-1/3 UK LPs. A long time ago I had a Rolling Stones LP with "FFRR" printed on the cover. Played back on a RIAA preamp, it sounded like it had bass boost.

It seems to be almost impossible to find this information on the internet. I had to get the RIAA information from a TI op-amp datasheet.

Lastly, does anyone know who manufactures LP recording equipment. This technology is making a resurgence. I sure would like to see the schematic diagram of the typical industry RIAA preemphasis encoder.

Thanks,
Bob
 
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audioguru

Well-Known Member
Most Helpful Member
There were strict standards for vinyl records and tape pre and de-emphasis. But each recorder used its own pre-emphasis to tweak the very low and very high frequencies to match their transducers to the standard.

Some companies like RCA fiddled with the response to provide (unwanted) presence with a boosted mid-range of frequencies.

Recording companies mess up the response so that their engineers are pleased with the output from their monitor speakers that are not the same as yours.
 

Bob Scott

New Member
There were strict standards for vinyl records and tape pre and de-emphasis. But each recorder used its own pre-emphasis to tweak the very low and very high frequencies to match their transducers to the standard.

Some companies like RCA fiddled with the response to provide (unwanted) presence with a boosted mid-range of frequencies.

Recording companies mess up the response so that their engineers are pleased with the output from their monitor speakers that are not the same as yours.
Thanks, Audioguru, but I'm not really concerned with how the talent and their recording engineers massage their musical artistic product with equalizers or the effects boxes they patch into the mix in order to make Lady Gaga sound good. She needs her voice digitally corrected by three Eventide Harmonisers AND a Vocoder just so she can sing on actual notes. My inquiry has to do with the recorders they purchase, which have built-in response characteristics at a low level, the hardware level.

Studio recording engineers don't tweak the RIAA encoder, or the NARTB response curves on the tape recorders they buy. They are not REAL engineers or even technicians now are they? They are just equipment operators. If they were caught tweaking those particular internal adjustments, they wouldn't be employed very long.

Bob
 
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audioguru

Well-Known Member
Most Helpful Member
Sure the recording engineers fiddle with the frequency response of each recording. To make it sound good to their ears as heard on their monitors. You might not like their fiddled sound.

Most listeners use a cheap sound system with poor bass so they record higher level bass frequencies for them. They figure that you can turn down your bass control if you have a good sound system.
Most listeners don't have enough power so they record with excessive compression to make the sound appear louder. Too bad for your good sound system.
 

flat5

Member
There used to be preamps that had a selection of presets for different curves. If you can find the model numbers and technical info for them...

How about old journals from the American Electrical Engineering Institute or whatever it's name. Industry standards were kept somewhere.
Good luck.
 
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