Issue link: http://digital.copcomm.com/i/1011374
38 Most "portable" mixers of the 1950's were still based largely on broadcast consoles manufactured by RCA, Western Electric (ERPI), Altec, and Collins. Again, all of vacuum tube design. The first commercial solid-state recording console wouldn't come around until 1964, designed by Rupert Neve. A replacement for the venerated Altec 1567A tube mixer didn't appear until the introduction of the Altec 1592A in the 1970's. A common trait amongst all of these designs was that nearly all of them were four input mixers. The only EQ provided was a switchable LF rolloff or high-pass filter. There were typically, no pads or first stage mic preamp gain trim controls. The mic preamps typically had a significant amount of gain, required to compensate for the low output of most of the ribbon and dynamic mics utilized in film production at the time (while condenser mics existed, they also tended to have relatively low output as well). All had rotary faders, usually made by Daven. And except for the three-channel mixers expressly designed for stereo recording in the 1950's, all had a single mono output. Re-recording consoles were of course much larger, with more facilities for equalization and other signal processing, but even these consoles seldom had more than eight to twelve inputs per section. THE 1960'S While the 1950's saw some significant advances in the technology of sound recording and reproduction, with the exception of the introduction of stereo sound (which was typically for CinemaScope roadshow releases), there had not been any really significant advances in recording methods since the transition from optical to magnetic recording. Power amplifiers and speaker systems had somewhat improved, boosting the performance of cinema reproduction. However, most mixing consoles relied on circuit topologies that were based on equipment from the 1940's and 1950's, with some minor improvements in dynamic range and signal-to-noise ratio. It was during this period that technologies developed for music and broadcast began to seep into the area of film sound, and the approach to console designs began to change. The most notable shift was a move from the tube-based designs of the 1950's to solid-state electronics, which significantly reduced the size and weight of portable consoles, and also for the first time, allowed for a design approach that could use batteries as a direct source of power, without the need for inverters or generators required to power traditional vacuum tube designs. This opened up a significant range of possibilities that had not existed before. With the introduction of solid-state condenser mics, designers began to incorporate microphone powering as part their overall design approach to production mixers, which eliminated the need for cumbersome outboard power supplies. Some mixers also began to include mic preamp gain trims as part the overall design approach (also borrowed from music consoles of the era), which made it easier to optimize the gain and fader settings for a particular microphone, and the dynamics of a scene. The 1960's would also see the introduction of straight-line faders (largely attributed to music engineer Tom Dowd during his stint at Atlantic Records in New York). In the film world, straight- line faders showed up first in re-recording consoles, which could occupy a larger "footprint." However, they were slow to be adopted for production recording equipment. This was due in part to some resistance on the part of sound mixers who had grown up on rotary faders (with some good-sized bakelite knobs on them!), but also due to the fact that early wire-wound straight- line faders (such as Altec and Langevin) fared rather poorly in harsh conditions, requiring frequent cleaning. Still, even by the end of the 1960's, not much had changed in terms of the overall approach to production recording. Four input mixers were still the standard in most production sound setups, with little or no equalization. But the landscape was beginning to shift. While RCA and Westrex were still around, they had lost their dominance in the production world of film (although RCA still had a thriving business in theater sound service arena). Things were about to change however. Part 2 will continue in the next edition. –Scott D. Smith CAS Nagra BMII mixer. This was one of the first portable mixers to include power- ing for condenser mics as part of the mixer design. Sennheiser M101 mixer. Another of the early entries to solid-state portable mixers. Sela portable mixer designed for use with Nagra recorders. Incorporating T-power for mics, and low-frequency EQ, this was an industry standard for years. Westrex RA-1518-A stereo mixer. Note the early ingenious use of straight line faders, which are actually connected to Daven rotary pots on the underside of the panel. (Authors collection)