11th April 2000 - Analogue sound synthesis

We seem to alternate between the second floor and the basement of the Baden-Powell House for our meetings. This time we had to find our way through the lower floor maze to the Gilwell and Brownsea Suite. Quite suitable for the dark sounds we were going to encounter. Christopher Hicks opened the meeting by introducing his boss at CEDAR Audio, Gordon Reid.

Most interestingly, as CEDAR is a company specialised in de-noising and de-clicking, Gordon's lecture was about probably the noisiest machines in the history of electronic music... analogue synthesizers! Analogue synths never went away, but today they are certainly making a huge comeback. The reason for this revival could well be that most people who are using synths got bored with using the presets of the digital era.

The history of synthesis can be rooted back to Mr. Helmholtz. His goal was to analyse sound, not create it. He verified the fact that musical tones consist of various frequencies. However, the first 'instrument' of the early synth years was the Telharmonium. Its sounds were broadcast over telephone lines. The only problem was that a tremendous amount of cross-talk occurred at the telephone exchanges. By the way, it weighed 200 tonnes - heavy metal!

Gordon continued his history class with the slightly more familiar Theremin and Ondes Martinot, devices that were widely used - for example, by Olivier Messiaen in his Turangulila symphony. In 1930, Telefunken brought out the Trautonium, the first production line 'synth' and which used neonoscillators. All these wonderful devices were followed by a string of inventions like the Tonewheel Hammond, the Clavioline (1947) and the RCA synth in 1956. The RCA synth had a programmable sound controller, being a punched paper roll. It was also able to record sound directly onto an internal lacquer disc. In 1963 the Mellotron was born which can be seen as the precursor of the sampler of today.

But synthesis as we know it only really came to existence in 1964 when Robert Moog laid the basis for it all. His idea was to use one voltage to control another. It is here that the terms VCO, VCA, VCF and LFO were introduced. The Voltage Controlled Oscillator generates harmonically rich tones. Then, the Voltage Controlled Filter modifies the spectral content of the signal by filtering certain harmonics. Its effect can even be increased by applying resonance such that it will greatly accentuate the frequency just before the filter cut-off point.

The Voltage Controlled Amplifier and the envelope generator define the development of the sound - how it changes in time. It is this process that makes the notes become more interesting and more musical. The last term, LFO, is the Low Frequency Oscillator. It generally ranges from 0.1Hz to 80Hz and gives movement to the sound. You can, for example, apply it to the VCO, VCA or the VCF. This gives vibrato, tremolo and growl, respectively.

The technical tour through the world of synthesis was continued with Amplitude and Frequency modulation. The latter on which the operation of the famous Yamaha DX7 is based.

Next, Gordon described another form of synthesis, namely, Additive synthesis. Here sine waves are summed together in order to create harmonically rich sounds. For analogue synthesis, this would have been almost impossible just for the sheer number of oscillators that would have been needed.

After the more in depth, technical operations of these machines, Gordon took us further along the time line starting with the Yamaha GX1 of 1974, the first modern polyphonic synth with the modest weight of 387 kg. We worked our way through the list consisting of Roland's Juno 60, Yamaha CS80, the Prophet 5 - which had the amazing memory of 40 sounds! Moog Source was the first to incorporate the Digital Parameter Access system. Roland's Jupiter 8, 1982, was the last big analogue synth from Japan. It was known for its delicate sounds, its "fairy dust". In '87 the Roland D50 introduced "Samples & Synthesis" (S+S). This was followed by the Korg M1 in 1988 which used PCM samples.

The race to combine analogue and digital ideas was won by Clavia who started to use Motorola DSP 56002 chips to emulate the analogue circuits used in the old analogue synths. Clavia developed the Nordlead and the Supernova (uses 9 DSP 56302 chips!!!). Analogue synths were pushed aside by the easy to use digital inventions. Easy to use, meaning, just dialling up the presets. Just try to get deeper into the menus of the DX7!

Today, analogue synths are wanted again. People like the sound; it is 'retro' and cool to have one and it certainly looks great. As we said before with the Clavia approach, the use of powerful Digital Signal Processors can be used to imitate the possibilities and sounds of analogue synthesisers. But, the one advantage that analogue synths have over the digital copies, or should I say clones, is the fact that every setting is unique.

Gordon Reid interlaced the history and technical explanations with demonstrations on his personal Roland Juno 60, his immaculate MiniMoog and the limited edition Korg Ms-20 Blackboard (1978). As usual the session was ended with a question round and warm applause for Gordon Reid.

And one more thing... get rid of all the 303s, 808s and 909s!

Wesley Maebe