Agree that Victor studio recordings tend to sound best with Victor's know "Orthophonic" playback 
curve. Pre-electric is a different story. US Decca's and 1940's Capitol 78's also sound best to my 
ears when played back with the common-wisdom curves widely published on the internet. Victor's 
location recordings are sometimes a different matter, but it may be inherent limitations of the 
recording rather than the recording curve and might be just as easily fixed with EQ post-Orthophonic 
preamp, I just like to avoid an external EQ if possible but there are valid reasons and appropriate 
times to use it.

I'm not sure how much original Columbia documentation there is on their common-knowledge curves, but 
those usually don't sound right to me. Mercury, Keynote and Majestic generally used the AES curve, 
although the Fairchild recorder that was used at Reeves studio had its own curve slightly different 
from AES, but AES works fine for playback of the mass-produced disks. For the laquers, you can make 
the rolloff more gentle and hear more of the extended top end of that system.

Does anyone know if there was company documentation of what Victor was using for on-location 
classical recordings in the 30's, for instance Minnesota in the mid-30's and Philadelphia in the 
same era? Orthophonic doesn't sound quite right but if could just be the recordings themselves were 
noisy and low-level.

-- Tom Fine

----- Original Message ----- 
From: "Bob Olhsson" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, March 07, 2011 5:37 PM
Subject: Re: [ARSCLIST] SV: [ARSCLIST] Turnover and rolloff curves for correct playback of 78 rpm 

> -----Original Message-----
> From Jack Theakston: "... Was real information about studio EQ published at
> the time?..."
> There were internal standards publications and test records that were shared
> among the Victor studios however many record labels were in the record
> player business and no doubt tweaked their curves for the benefit of their
> own products. I'd guess that most used crystal cartridges with no other
> playback eq. and their recording channels were probably aligned accordingly.
> Around 1940 Victor began using what they called the Orthacoustic curve which
> was pre-emphasis very similar to what would later become the New
> Orthophonic/RIAA curve. This method had become SOP at NBC after some
> experimentation during the mid '30s so the record division finally adopted
> it. At the same time they dropped the mandatory use of an 8.5 kHz. low pass
> filter that was much like the Academy Curve used in motion pictures.
> Bob Olhsson Audio Mastery, Nashville TN
> Mastering, Audio for Picture, Mix Evaluation and Quality Control
> Over 40 years making people sound better than they ever imagined!
> 615.562.4346