[78-L] 1937 shellac test pressing outperforms audio CD

[Eric Jacobs]

I apologize in advance for cross posting.

I couldn't help sharing this - I am regularly measuring 27.2 kHz 
harmonics and occasionally as high as 43.6 kHz harmonics (violin)
from a series of 1937 RCA Victor test pressings - nearly 72 years
old.  I'm pretty fastidious about accurate cartridge loading, so 
I don't think we're seeing ringing of the transducer.

Never mind that we've invested nearly $60k in our analog disc 
playback and digitization system, pushing the limits of what is 
possible, but I was astounded by the recording quality and 
performance of these particular discs that long preceeded modern 
formats like magnetic tape and LP, let alone CD.

For those who have the ability to measure this sort of thing,
I can email 1-second and 2-second samples (24/96 WAVE files).
For those that do not have access to a high-resolution spectrogram, 
I can send jpegs taken from ours.  The WAVE files altogether are
2.3 MB - not especially large - but you should still make sure 
that your email software and internet connection can handle email
of this size.


Eric Jacobs

The Audio Archive, Inc.
tel: 408.221.2128
fax: 408.549.9867
mailto:EricJ at TheAudioArchive.com
http://www.TheAudioArchive.com
Disc and Tape Audio Transfer Services and Preservation Consulting