Posts Tagged ‘Decca Recording Studios’

More About Cassettes

Wednesday, February 2nd, 2011

Back in the late 1980’s, long before the days of Pro-Tools and Cubase multi-track recording, manufactures were trying to squeeze every possible ounce of usefulness out of existing analogue technology. Professional multi-track tape recording had been around for a number of years, most famously the 4-track recordings of the Beatles Sgt Pepper album at Abbey Road studios in the mid 1960s.

By the early 1970s 8 and 16 track machines were common place in most recording studios, in Decca’s West Hampstead studios, studio 2 (mostly used for groups and small bands) was equipped with a Scully 8 track machine, and after it’s refurbishment in 1973, the giant studio 3 (mainly used for large orchestras) was equipped with a 3M 16-track machine. In the 1980’s manufacturers for the domestic market, home studios and demo recordists produced various types of 4 track tape machines and ultimately 8 track too.

Tascam 238S

Tascam 238S

Some were reel to reel machines but most were based around the Philips Compact Cassette format.

The machine shown here was made by Tascam – the 238S – and was manufactured around 1988. The fact that the deck was  made for a cassette meant this was cheap to run and gave very good results. The deck ran at 3¾ inches per second, and would use high bias type II tapes. The heads were aligned to interleave the 8 tracks with even tracks grouped together and odd tracks grouped together this meant that the full width of the tape was used allowing only one pass of the tape – there was no side 2. The deck incorporated Dolby S that provided 10dB of noise reduction at low frequencies and 24dB of noise reduction at high frequencies. These combinations of good quality tapes, a faster tape speed and Dolby S gave some very good recordings. Added to its impressive pedigree was dbx, which was a wide band compression-expansion system that provided a net noise reduction system (dealing with broadband noise not just tape hiss). In effect the dbx system could give a 90 dB dynamic range very impressive for a small cassette. This one seen here in our studio has seen plenty of active service and in its lifetime I have used it to record many choirs, bands and a variety of singers. In my opinion this was the ultimate machine for squeezing the best out of the humble cassette.

The 1990s then saw the production of many digital tape machines, Tascam famous for the DA-88 in 1992 supported 16 bit/48kHz format recording onto Hi8 tapes. This technology has come along was with Tascam’s latest machine, the DR-680, offering 24 track capacity at 96kHz/24 bit recording onto an SD card.

Acetate Discs

Wednesday, July 21st, 2010

At Lost Sounds we receive many acetate discs from private collectors, as well as record companies, requesting the discs be restored and converted into a digital format. For most private collectors this is usually onto a CD and for our commercial clients the request is often to 24 bit/96 kHz.  But many readers and followers of this blog may have never seen or touched an acetate.

Acetate discs were cut as a pilot or reference disc for artists and production staff to gauge how the material would sound once transferred to disc, could the bass be held at the recorded level, did the stereo image transfer satisfactory, how does the material sound on a variety of decks and playback equipment. So an acetate was usually the very first cut of an artists material and may not even resemble the final versions that were then made commercially available.

Physically an “acetate” is far more rigid than a vinyl disc, it is manufactured with an aluminium core (the metal can be see on the edges and in the hole), which was then coated with nitrocellulose. Often they are 10″ (7″ singles were also cut onto this size disc) or 12 “, however we have also handled a few 7″ acetates.

Acetate

Acetate

The example shown in this picture is a 12″ acetate with only 2 tracks playing on the EMT deck . The material was a rare early 1960’s recording of Dave King and Glen Mason singing two songs together. As is often the case the B side was blank.

Acetate discs are less robust than vinyl, they were never designed for multiple plays, therefore many, today, carry high surface noise and because many have been used in a commercial environment they have not had a great deal of TLC! After a lot of work restoring this disc the material was transferred to CD for a private collector.

It is important to note that when wet cleaning an acetate do NOT use the method outlined below which is specifically for vinyl discs. Applying an alcohol based chemical to an acetate or indeed a shellac pressing could seriously damage the surface therefore great care should be taken. If your acetate discs need to be cleaned use a photographic wetting agent heavily diluted in de-ionised (distilled) water, if the disc is marked with finger and/or hand prints make sure the de-ionised water is warmed to just above body temperature this will dissolve the grease. Use a soft cloth, as for vinyl, and rinse thoroughly in plenty of  de-ionised water then leave the discs to dry for some hours before playing.

Disc Cutting

Sunday, December 6th, 2009

The black art of disc cutting has always intrigued me and I always had great admiration for my colleagues in Decca who had mastered this skill and demonstrated it with precision.

Pre 1950 virtually all recorded material was cut directly to wax discs. Radio stations used 16” transcription discs which operated at 33.3rpm and had capacity for 15 minutes of material on each side. While at Decca I had the privilege of transferring the entire collection of Bing Crosby’s radio recordings from such discs. These programmes had been sponsored by Kraft, Chesterfield Cigarettes and Philco Radio and had been broadcast in America throughout the 1940s and 50s. However, due to problems with copyright, we were unable to release any of the restored material at the time which was unfortunate because the shows included a host of top names of that era, Al Jolson, Anne Shelton, Bob Hope, Andrew Sisters to name just a few.

Once magnetic tape was adopted in recording and radio studios around the world the need to cut direct to disc was soon abandoned. All recordings were made to tape with the advantage of editing, re-recording, multi-tracking and greater versatility.

The disc cutter came into his own when the finished master tapes were passed to him for transfer to disc. Developments in the 1950s meant that wax discs were replaced by lacquer-coated metal blanks. The lacquer was a cellulose nitrate coating soft enough to be easily engraved by the cutter yet hard enough to permit a number of direct plays. This ruggedness meant that during the cutting operation the engineer could monitor the quality of the cut by switching between the signal applied to the disc and the audio actually cut onto the disc. The picture below shows Decca disc cutting engineer Harry Fisher using a Neumann cutting lathe to produce a master lacquer disc. Harry had a great fondness for music from the 1940s and 50s and was therefore always assigned the tasks of cutting the material I worked on. Every cutting engineer would leave his insignia in the run out groove of the discs they cut, we termed it the “dash number” Harry’s was always W, Trevor Fletcher, who cut all the Decca singles was C. Their insignia was always preceded by the lacquer reference number. For example if a disc was the first cut from the master tape the dash number would be -1W. Sometimes the master discs were damaged in the processing operation at the pressing plant. A second or third disc would then need to be cut; these would be -2W or -3W and so on.

Decca Disc Cutting Room

Decca Disc Cutting Room

In the photo you can see Harry inspecting the quality of the groove using a x40 microscope. To the right of the picture (just out of shot) is a rack carrying the high powered amplifiers necessary to energise the cutting styli. These amplifiers were generally operating in the order of 600w per channel, this amount of power generated heat on the coil cutting head of 200 degrees Celsius. This was cooled using helium gas. The stylus itself was heated which allowed a smooth cut in the lacquer therefore reducing surface noise.

Other points of interest in this photo: firstly the Decca made console in the middle of the shot. Every cutting room and tape duplication room had a similar sized console with standard equipment; Decca designed and made equalization units, limiters, test tone generator, quadrant faders and remote control switching units. Also seen in this shot is the triangular shaped meter panel. All monitoring at Decca was performed with PPM meters working to a reference point of + 4dBm, peak recording level was usually +8dBm. For comparison purposes a pair of VU meters were also on this panel. On the rear of the console you can see the patch field. To the left of the console and built into a white cabinet is a Garrard 301 turntable for the playback and quality check of new pressings as seen on the table. Outside of the shot is a Philips Pro’ 51 tape machine. These machines were standard in most of the rooms by the early 1970s. The Pro’ 51s used in these cutting rooms were especially modified by our engineers to include an extra playback head. This head was situated before the main bank of heads and allowed an early audio signal to be sent to the lathe for groove adjustment depending on modulation variations.

My grateful thanks to Wes Stillwagon who administers the excellent Mantovani web site: www.hallowquest.com/ and who kindly allowed me to reproduce this photograph.