Electronic Music Laboratories (EML) was an American synthesizer manufacturer in the 1970s, based in Connecticut. The company was an industry pioneer in the use of integrated circuits and high-specification components (many of the parts used in EML's synths were military spec). It is said that the company's founders, including Dale Blake, Norm Millard, and Jeff Murray, got into the synth business by accident: in 1968, they were looking for a line of business to go into because of fears that they were about to be laid off by their current employer. An associate of theirs had bid on and won a contract with the area school system to build demonstration electronic instruments for the schools, but he was losing money on it. The EML founders took over the job, turned a profit, and then invested that in developing improvements to those instruments.
The following year (after they were indeed laid off), they introduced their first products, the Electrocomp 100 semi-modular synth and the 200 expansion module. Based on user feedback, they made some improvements to the 100 and introduced the Electrocomp 101 the following year. They struck pay dirt with this four-VCO synth: it was more reliable and cost less than the competing products from ARP and EMS. About 1000 were eventually sold, and it became EML's most popular model.
Later products under the Electrocomp line included the 300 synth, the 400/401 synth/sequencer combination, and the 500 synth. The 300 was designed for experimental musicians and only a handful were sold. The 400/401 consisted of a two-VCO monophonic synth combined with a versatile and innovative analog sequencer. It was a bit too far ahead of its time and sold poorly because musicians at the time weren't sure what it was good for (it is now highly sought after by collectors). The 500 was an attempt to enter the performance-synth market; it basically consisted of the 400 synth core in a case with a keyboard. Competing against the better sounding Minimoog and more versatile ARP Odyssey, it also did not sell well.
The company had a near-miss with its first polyphonic synth, the SynKey, in 1976. Two years before the Prophet-5, this EML model had (sort of) 13 voices and a form of patch memory. Unfortunately, the memory consisted of plastic punch cards that had to be laboriously hand-punched by the performer in order to create new patches. Some musicians also did not like the sound of the divide-down oscillators and the additive synthesis method they relied on; they complained that everything came out sounding organ-like. The repercussions of the SynKey's market failure caused the founding group to split, and EML developed no further synth products (except for the oddball Polybox, which provided a crude form of polyphony to monophonic synths).
Although the company existed until 1984 doing contract engineering, various reports have it that synth manufacturing ceased sometime between 1978 and 1981. EML's founders were engineers and not musicians; this was both a blessing and a curse. It was a curse because the engineers didn't always understand how musicians wanted their products to work (leading to unfortunate decisions like the use of the punch-card memory on the Syn-Key), but it could also be a blessing because they weren't constrained by the existing Moog/ARP designs. EML's products, particularly the earlier ones, more resembled scientific instruments than musical devices; some performers found this off-putting but others were attracted to it. EML's circuits were regarded as more reliable and more stable than their competitors, although there was a widespread dislike of the anti-oscillation feature of their VCFs. There were certain aspects of EML's designs which were unconventional but quite effective once understood
As previously mentioned, in the collectors' market today, the 400/401 combo is the most highly sought after, followed by the 101 and the 200. A problem that the collector will face in interfacing EML gear to other synths is that EML used a scaling of 1.2 volts/octave, as opposed to the 1 V/oct de facto standard established by Moog. (The 1.2 V/oct scaling actually makes sense when one considers that it is equivalent to 0.1V per half step, and it's actually a bit unfortunate that the industry didn't adopt that standard.)