Meeting Topic: Audio Tape Recovery and Restoration
Moderator Name: Rob DiVito
Speaker Name: Richard Hess
Other business or activities at the meeting:
Rob DiVito greeted everyone.
He announced next month's meeting taking place May 22nd at Revolution Studios. He reminded the audience of the Toronto AES LinkedIn and Facebook pages and to join them. Finally, he asked the audience to participate in the online survey which ends this month.
Rob provided his regular tech talk update. One item that produced discussion amongst the audience was the Millenniata M-Disc technology which attempts to address the degradation of archival media. Sy Potma noted the inner material is more stone than organic material. Richard Hess offered the information that MAM-A blu discs are using inorganic dyes.
Meeting Location: Ryerson University RCC 204, Eaton Theatre, Rogers Communications Building 80 Gould Street, Toronto, ON
Rob introduced Richard Hess and provided his credentials:
Richard Hess began his affiliation with tape recorders at age 10 in 1962, when he bought a Wollensak with money he had saved. After graduating with a BS degree in Communications from St. John's University in New York City, he joined the Engineering Department of ABC Television in New York and worked there from 1974-1981. Moving to Toronto in 1981 to join McCurdy Radio Industries, he worked his way up to Director of Engineering, leaving in 1983 when the company was sold.
In 1983, Richard moved to Glendale, California to join National TeleConsultants, working there until 2004. He held titles such as Senior Project Director, Director of Engineering, Vice President, and Principal Consultant. He was responsible for oversight on many large projects, preferring the technical side.
In the late 1990s, Richard started becoming aware of incipient tape degradation in his own personal archive and started restoring and digitizing tapes for his friends. This became a business and, in 2004, he and his family decided to return to Aurora, Ontario, his wife Mary Beth's hometown, and go full-time into audio tape restoration.
In October 2006, he presented a paper at the San Francisco conference of the Audio Engineering Society on "Tape Degradation Factors and the Challenges in Predicting Tape Life" which was published in the Association of Recorded Sound Collections Journal in the Fall of 2008.
Mr. Hess began his presentation by providing a history of Milestones involving telegraph and recording.
Some notable points included:
In 1878, Oberlin Smith described the theory of magnetic recording. This was within well known milestones such as Edison's phonograph patent. His work was published in 1888. In 1898 Valdemar Poulsen presents the Telagraphone.
He played a sample of a Telagraphone recording of Emperor Franz Joseph of Austria made in 1900.
Audio becomes 'mainstream': In 1930 the Blattnerphone was introduced to the BBC. 1933 saw the Blattnerphone brought to North America.
In 1992, a Blattnerphone recording of the 1937 Coronation of King George off BBC shortwave was found.
Mr. Hess displayed a picture of a 1933 vintage Blattnerphone.
He played back some more sample recordings. Utilizing steel tape, the Blattnerphone operated at 1.5 meters/second! BBC operators were prohibited from being in the machine room during its operation.
Tape recording as we know it began in 1935 when AEG exhibited the Magnetophon K1.
He played back a recording of Sir Thomas Beecham conducting the London Philharmonic. Noise was evident in the form of rumbling. He then played a version which he decoded with Algorithmx Noise Free Pro Noise Reduction System. The recording was made with one Neuman CB3 microphone.
AC bias was the missing link that made magnetic recording work well. It was a pivotal development reducing distortion and noise. First applied to audio by Bell Labs ca. 1939 but not promoted until 1941.
Mr. Hess played a sample made in May 12 1941, Berlin, of an opera singer. The recording had a lower noise floor, but contained overload distortion due to the poor understanding at the time the operators had of overload capabilities of magnetic tape.
In 1943 and 1944 experiments with stereo recordings were attempted. Mr Hess played such a sample of von Karajan conducting the Bruckner Finale of the 4th Symphony.
Mr. Hess offered some background regarding his own recording activities, and his archives. He noted that "just because you can't play the tape doesn't mean it's trash!"
While the CBC had the Blattnerphone in Canada since 1933, professional tape recording 'began' October 1st, 1947 in the U.S. with the Philco Radio Time broadcast with Bing Crosby.
He displayed slides of tape in various states of dis-repair brought back by Jack Mullin in 1945. One was even in pieces and collected in a paper bag which was later painstakingly pieced together at Stanford.
He then offered a list of some of possible track configurations of various widths of tape starting with 1/8 inch tape: 2 track mono cassette, 3 track Revere Cart, 4 track stereo cassette inline, DCC (Digital Compact Cassette), DAT, and 8 track Portastudio tapes.
For 1/4 inch tape this includes full track mono, 2 track NAB, 2 track DIN, Sony DasH, 3 track and TOMCAT cart, 4 track, 5 and 6 track which were used for logging in Europe, 8 track 4 ch, 8 track Fostex.
Half-inch configurations include track counts of 2, 3, 4, 7, 8, 14, 16 and 20. 20 track tape was used for logging applications while 7 & 14 track was used for instrumentation tapes.
One inch tapes include track counts of 4, 8, 12, 14, 16, 28, and 40. 14 and 28 counts were for instrumentation, and 40 counts were for logging.
Two inch tape includes 8, 16, and 24 track counts.
Digital Formats include: Sony PCM F1, dbx 700, 8 track DTRS, 8 track ADAT, stereo mini disc, multitrack mini-disc (porta-studio).
Companding Noise-Reduction systems include: Dolby A, B, C, S, and SR; dbx I and II, Burwen, Telefunken C4, High Com I and II, Sanyo Super D, Toshiba ADRES, and JVC ANRS and Super ANRS.
Speed, EQ, and Modulation: Audio tape can have speeds from 15/32, 15/16, 1-7/8, 3-3/4, 7-1/2/, 15, and 30 ips. Instrumentation adds 60 & 120 ips to the list!
For equalization IASA compiled all the standards that were done.
For modulation: with audio we have direct modulation with equalization. With instrumentation there is Constant Flux (direct) FM, FM multiplex, and PCM.
All this can total at least 3360 permutations! Not counting at least 64 permutations on instrumentation tapes.
He then played back some more 1946 Magnetophone samples.
Mr. Hess puts the date at 1954 when high quality stereo becomes the norm noting the companies that were starting to produces such recordings. Two track stereo tapes were sold in the mid to late 50's until 1/4 track stereo came out, which he considered a step down in home quality.
He played two samples back to back of the same piece of music, one recorded Nov 19 1963 and the other Feb 13 1994. The 1963 recording was made via a national radio network at a remote site several thousand cable miles from the source, and the later one was an on-location recording. The 1963 recording was as bad as it was because of the long line between the source and recorder. If it had been recorded locally, it could have been much better.
It was notable that the two different interpretations almost matched in terms of tempo and dynamics!
He discussed how tapes were transported between stations for radio broadcasts and played samples to demonstrate the deterioration that could occur with multiple tape copying and processing.
His advice: "Always find the master tape or as close as you can". It pays to search. Mark Donahue did it for the RCA Living Stereo recordings.
He recounted the restoration of John Allan Cameron's first 1968 album. It was a story of how not to store tapes. They were stored in basements without the tape boxes. He discussed the outcome the moisture problems had on the tapes.
"Sometimes you get lucky": He then played a pristine and clear sounding 96/24 transfer of Stan Rogers "White Squall" from the "Fresh Water" LP released in 1984 after his untimely death.
Azimuth was the next topic. He stated the only way to best adjust azimuth is by ear. He demonstrated the importance of azimuth adjustment by playing a before/after example of a spoken word recording, first out of, and then, in azimuth.
On the topic of cassettes, he stressed not to rule them out as sources. He played an amazing example of a cassette recording from 1976 of Jean Langlais at The Church of the Heavenly Rest NYC, transferred in 2003 using a Nakamichi dragon. The cassette was originally made on a Nakamichi 550 by Richard with AKG C451 mics.
He next played more before and after spoken word tapes to illustrate cleaning up a buzz where he could not determine the fundamental frequency, having to resort to manually notching out the offending tones with as many as 15 filters.
The subsequent samples illustrated problems dealing with room noise.
He then played some more samples: a jazz recording from 1981 that was originally mastered live to an Ampex 1/2" ATR102@30 ips. The current sample was a 15 ips 1st generation copy made on an Ampex 351 with modified Innovonics electronics.
He played a live classical recording he made in 2011. A brief audience discussion ensued wondering how he 'removed all the coughs'! He replied simply he was lucky. The recording unit was made by Sound Devices. "No tape was used to record that!"
All his samples this evening were played from 96/24 files. Those that weren't originally at 96/24 were up-converted in Samplitude 11.
He took some questions from the audience. The topics ranged from the first commercial use of tape, tape baking, humidity and his archival system. A debate ensued regarding archiving vs. migration. Richard ended the discussion stating one "can only archive on a managed storage system". It was suggested this would make a topic for another section meeting.
Rob thanked everyone.
Written By: Karl Machat; introductory bio by Earl McCluskie