In 1975 American inventor Ken Schaffer created the first dependable, beautiful sounding wireless system for electric guitar and bass. Little did he know he was also creating a circuit that would transform the sound of rock and roll.
The original Schaffer-Vega Diversity System (SVDS) was the first reliably working and beautifully sounding wireless system for musicians or, in general, stage performers. Other wireless microphone systems pre-dated the SVDS, but never became widely adopted because even the best of them lacked reliability (fade-outs, police and taxi dispatch calls!) and their sound was nothing to cherish, especially at high decibel rock n’ roll sound levels. When attending to a Rolling Stones soundcheck, genius inventor Ken Schaffer was baffled by the amount of interference and fade outs that plagued the current-generation wireless units being used by Mick Jagger – he thought he could do better – and he did. Thus, the Schaffer-Vega Diversity System was born.
Ken Schaffer was a New York-based recording engineer-turned publicist who had moved on from the record business in order to focus on being a full-time inventor. The first wireless prototypes saw light in 1976 and in 1977, full production was running. The Schaffer-Vega Diversity System was catching on with some of the big names in rock. One of the early adopters was KISS, whose motivation was one of practicality since guitarist Ace Frehely once had to be revived after having been shocked by a guitar cable connected to an ungrounded amplifier. Within a few years, you couldn’t throw a brick in a room full of household name guitarists and bassists without hitting someone who was using the SVDS in a live setting; Eddie Van Halen, the Rolling Stones, Bootsy Collins, Peter Frampton, Frank Zappa and numerous others were all SVDS users. However, Schaffer designed it to boost low-mid range frequencies usually lost in wireless transmission, as well as to compand (compress then expand) the signal, thus providing the added side effect of enhancing the instrument’s tone. Numerous groups decided that, apart from serving its basic function, the SVDS also sounded good and began using it as an effect in the recording studio – namely Electric Light Orchestra, Pink Floyd (The Wall) and, of course, AC/DC, beginning with 1978’s Powerage.
Says Angus Young, “George [Young, Angus and Malcolm’s older brother and first AC/DC producer] had suggested that I use the SVDS in the studio in 1978, then when Mutt Lange came in [producer of Highway to Hell, Back in Black, For Those About to Rock We Salute You], he asked me to use the same stuff that I was using for my stage sound, so we used the SVDS again.”
This unit changed the way Angus Young sounded and played.
The device was prohibitively expensive for the time ($4.100USD, roughly $20.000 USD in today’s money), but famous performers did not hesitate and bought one (or two! Pink Floyd bought 20!) units because of its quality and reliability. It was probably the only choice for use with live musical instruments in the 1970s. The SVDS was actually used well beyond 1981 (year of cessation of production) by some artists – there are documented pictorial evidences of this (Pink Floyd’s David Gilmour for instance, as pictured here in the mid 80s).
Schaffer’s design incorporated two antennas – as used by the army – so when one antenna would go down, the other one would still pick up the signal (such a setup was called a diversity system), as well as an ingenious pre-processing circuits to preserve the integrity of the wireless signal. Notably, a mirror-image paired compressor and expander increased the radio circuit’s dynamic range to over 100 dB, 35 dB greater than the theoretical maximum that could otherwise previously be achieved within the bandwidth limits covering wireless systems by the US FCC. Schaffer wanted to make sure that the SVDS would be capable of being used with musical instruments such as electric guitar, which, according to Schaffer himself, was a much more difficult task to accomplish because of the guitar’s stronger attack and richer harmonic content.
Beyond the staging freedom afforded by Schaffer’s wireless, many A-list players discovered something unintended: the sonic result was pure magic! The wireless design’s unique preprocessing enriched their signal with copious amounts of harmonic content unlike anything they’d ever heard. News traveled fast. Schaffer’s wireless units became the system of choice for nearly every major artist of the mid-70s to mid-80s.
By 1982, after becoming interested in other endeavors, including intercepting internal Soviet television for the U.S. government in the waning days of the Cold War, Ken Schaffer ceased production of the Schaffer-Vega Diversity System. Soon, new, stricter FCC regulations on wireless specifications prohibited fully-analog wireless systems of its caliber from being used. SVDS artists – including AC/DC – were forced to move on… the legendary “Schaffer Sound” slipped into obscurity.
To listen to more stories directly from Ken Schaffer – listen to this great intervew by the AMPS & AXES SHOW.