I finally figured out how to power the Sennheiser MKH-104, 404, and 804 from 48 V phantom power (P48) which is very common on professional and many prosumer mixers and recorders. The MKH-X04 series requires -8V for operation. Please note that some portable recorders do not generate P48 even on their XLR connectors. This will not work with P12 or P24 inputs. It works like a charm on P48 inputs (at least from Mackie, Yamaha, and Sound Devices). Thanks to everyone for their input and assistance.
history
US Music Media Statistics through 2016
| This is the updated graph showing percent of music sales by format from 1973 through 2016. |
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| Click on the images for a larger view. |
Images of Scotch (3M) tape boxes available
| I was interested in the progression of the Scotch/3M tape boxes over the years, especially after Carmine Lauri contacted me because his father was in the picture of a chamber orchestra on the 1960s Scotch tape boxes. Click on each image to see a larger one. Any moire pattern you may see is the screening of the printing on the box beating with the pixel/dot pattern of your monitor. |
 
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RCA “Sound Tape” cartridge and 1/4-track reel introduction dates
David Dintenfass kindly sent me an article from the October 1959 issue of Popular Electronics which says, in part, that RCA plans to have 65 titles in the stores in their new cartridges by Christmas 1959. Other manufacturers were shown to be making compatible players.
Five historic standards now linked from the history page
About two years ago, I asked the EBU to make available a copy of their historic document, Review of existing systems for the synchronisation between film cameras and audio tape-recorders and they complied, making it available on their website.
I asked the National Association of Broadcasters about their Cartridge, Cassette, and Reel tape standards as well as their Disc standard and they gave me permission to post these standards at my website.
These five standards plus some other articles of historic interest are available here in the history portion of this website. I hope that you find these of use in unraveling some of the challenges that old media present.
Microphone Powering Schema
In addition to my business of transferring tapes, I also record a few community groups for fun. Someone recently gave me an older Sennheiser MKH-804 interference tube (“shotgun”) microphone. Finding information on how to connect it proved more difficult than expected.
In the 1960s, transistorized microphones from AKG, Neumann, Schoeps, and Sennheiser became available. There are several niches of early microphone powering that continued on for many years. Perhaps the easiest way to look at it is backwards.
40th Anniversary of Apollo 11 Moonwalk and the loss of data
There has been much discussion over the last few years about finding and saving original tapes of the Apollo 11 Moonwalk videos downlinked from the moon. There is also an exciting project going on to restore and digitize the Lunar Orbiter tapes from more than 40 years ago.
The Lunar Orbiter tape digitization folks have just posted a commentary that bears reading by all archivists who are holding tapes. You may link to it here. The main site is www.moonviews.com
NASA, in their press conference yesterday held at The Newseum, admitted that the original 14-track 1-inch instrumentation (IRIG) tapes that contained the slow-scan video direct from the moon were most likely recycled and reused for later missions. Apparently, over 350,000 reels of instrumentation tape were recycled by NASA over time. No one apparently thought to preserve the 45-odd reels of the original moon walk.
Compander-type Noise Reduction Systems
Note: This information has been incorporated into this page which contains a more in-depth discussion.
I received an urgent phone call yesterday from a man who had digitized several reels of 2″ 24-track analog recordings that he wished to re-mix.
The tapes were originally recorded in about 1978-1979 and he said that he needed them to have Dolby C noise-reduction processing applied to the files.
I did a bit of research, as that did not sound correct from an historic point of view.
Here is an approximate chronology of the major noise-reduction systems and their dates of introduction:
IASA TC04 Guidelines on the Production and Preservation of Digital Audio Objects available online.
The International Association of Sound and Audiovisual Archives (IASA) has released their landmark Guidelines on the Production and Preservation of Digital Audio Objects as a free web (HTML) edition, available here.
I provided some information for the listing of tape equalizations, and I find the compiled table (here) most useful.
Thanks to Kevin Bradley and the IASA team for their work in making this available. If you want a PDF copy, join IASA and it’s available.
Cassette equalization redo
There has been much discussion on some web fora about the differences between different brands’ cassette equalization standards.
As I stated here in 2006, there is a 4 dB ambiguity at 16 kHz.
Many things conspire to make this 4 dB ambiguity essentially meaningless in a generally low-fi medium. The only reason I’m mentioning this now is that I’ve been bombarded with email from more than one participant in this discussion and apparently there may be some editorial judgment attached to what is posted.
Jay McKnight has graciously permitted my posting of his comments to me:
Obsolete data formats
This is a reminder that data formats come and go just like audio and video formats. On this, the 48th anniversary of the JFK assassination, this article was posted at the Library of Congress website. It talks about first locating and then converting research data held on IBM 80-column punch cards. I remember working with those my first summer job back in 1967! I guess I have a penchant for obsolete formats, as I learned a good deal about IBM’s unit record equipment, including the amazing 407 (introduced in 1949). That certainly was not as useful as knowing about analog tape now.
The punch cards were found and converted. This is a much happier fate than that suffered by the original IRIG 14-track 1-inch tapes of the Apollo Moon Walk from 1969! In 2011, I digitized 14-track 1-inch seismic tapes surrounding the Mount St. Helens eruption in 1980, and am working on another confidential project in 2018.
Protecting the container: Heritage Building Fire Safety
While this post does not specifically pertain to audio tape restoration, it does pertain to keeping originals and copies safe, especially in heritage buildings.
This article is prompted by a devastating fire in Aurora, Ontario, Canada, where I have lived for the last 10 years and also from 1981-1983. On Friday, April 11th, there was some roofing work being done on the 135-year-old Aurora United Church. Roofers were using hot tar and allegedly some sort of open flame. Humidity is not high in the winter and we had a cold one. The church roof structure (and much of the ceiling structure of the nave) was wood. Hot tar, flame, low humidity, wind, and very dry old wood do not mix well, and the results, sadly, were predictable. The church is now a ruin. The fire department spent 4-5 hours with up to maybe 7-8 master streams running into the attic and other parts of the structure.
US Music Media Statistics
Pete Hammar and Tom Fine came across a great site detailing 40 years of music statistics in a series of pie charts for each year. I thought it might be interesting to show this as a graph:
(Click image for full-sized view)