Moog Source

Synthesizer (Retro)

 

Reviews : Keyboard

 

Squelchy as a Minimoog and programmable as a PC, it's time to re-evaluate the Moog Source -- so says STEPHEN BENNETT.

There was a time when the name Moog was synonymous with synthesizers. Had the company remained the only player in the market, the verb 'to Moog' might have achieved common currency, along with Hoover and Sellotape. I remember someone coming up to me at a gig and asking; "Is that Moog you're using an ARP?" With its oscillators, mixer, filter and amplifier, the Minimoog's signal path blazed a trail for a generation of analogue synths. Moog's reputation for innovation was well deserved -- nowhere more so than in the subject of this retrospective review, the Moog Source.

The Source is a strange beast to behold, its tasteful, wooden end cheeks paired with a rather 'dayglo' front panel. The switches are the flat bubble type you may remember from the Sinclair ZX81. Believe me, this panel is impervious to liquids. Someone once urinated on mine as it was waiting to be loaded into its flight case at a gig. A quick rinse with water and it was right as... er, rain. Disgusting, but true.

 

WHAT IT IS

The Source is a monophonic analogue synthesizer with two oscillators per voice, a noise generator, a self-oscillating filter and two envelope generators. The keyboard is a light, 37-note C to C type, and there is an octave up/down switch next to the modulation and pitch wheels. The two oscillators can be set at three fixed, roughly octave-apart pitches, and oscillator 2 can be fine-detuned to plus or minus an octave.

There are three waveforms on each oscillator. These are sawtooth, triangle (which is very smooth and almost a sine wave) and square wave. The latter has an adjustable pulse width, but this cannot be modulated in any way.

The oscillators can be sync'ed together, and have that typical Moog 'distorted' quality at their maximum level. The outputs of the two oscillators can be mixed together and sent, along with a variable white noise source, into the voltage-controlled filter (VCF). The filter cutoff can be set to open up as you play higher up the keyboard, and has its own Attack, Decay, Sustain and Release (ADSR) controls -- though these are called 'contour generators' on the Source. The final link in the signal path is the ADSR controlling the output amplifier. The Low Frequency Oscillator (LFO) has triangle and square waveforms, and can be applied to the VCOs or to the filter, but you can't use it as a third oscillator, as you can on the Minimoog. The performance panel has the Moog-type, non-sprung modulation and pitch wheels -- and very nice they are too.

The main feature which sets the Source apart from other monophonic synthesizers of its day is its programmability. The Source was, I believe, the first synth to use the parameter access system of programming which is so ubiquitous today. Before the Source, each parameter on a synth had its own knob or slider for setting the value. On the Source, as you choose the parameter to be edited, its value appears in the LED display. You then you use a continuously rotating knob to change this value.

The Source's 'alpha dial' is a very interesting device in itself. It uses a bar code-type widget set around the spindle of the knob, like a skirt. An optical reader measures the direction and amount of movement of the dial. It also has a really nice spin, in keeping with the overall 'quality' feel of the Source. Remember, this was 'state of the art' in the early '80s! Edited patches can then be stored in 16 memory locations, and these can be dumped to cassette tape. More echoes of the Sinclair ZX!

 

 

CLEVER BITS

The innovations on the Source continue with the synth's method of promoting pitch stability. Analogue VCOs (Voltage Controlled Oscillators) are renowned for their inability to stay in tune. This is mostly, as long as high-quality parts are used, due to the changes in ambient temperature affecting the components making up the VCO. When I played a Minimoog live, I had to retune the bloody thing every 20 minutes, otherwise the oscillators would be playing a fifth apart by the time the encore came. Moog tackled this problem on the Source by raising the internal temperature of the synth to about 35 degrees centigrade. As a result, the Source runs very hot indeed, and as it bears a passing resemblance to a ceramic hob, it's tempting to try and fry an egg on it during those long overnight sessions. Despite this, I have to say that having the synth run that hot seems to work -- mine stays pretty much in tune.

There are a few other features on the Source, aside from the sound generating part. Firstly, there is a nice, if unsophisticated arpeggiator. Just press the arpeggio switch, hold a few keys down, and the arpeggiator goes off cycling around them. You can apply sample and hold to both the pitch and filter cut-off, for those Radiophonic Workshop 'Bleep and Booster'-type sounds. There is also a very simple and virtually useless sequencer. The Source was (just) pre-MIDI, and the only controller inputs are gate trigger and control voltage, using the Moog standards of S-Trigger and a 1 volt/octave control voltage (CV). Only the pitch of the instrument can be controlled by CV, though there was apparently a later model produced for a while, which had a primitive MIDI specification and, I believe, a filter CV input. I have to say I've never seen one, however. My Source works perfectly well with a MIDI-to-CV interface.

 

 

WHAT DOES IT SOUND LIKE?

The Source has the 'classic' Moog sound: a dirty, warm low-pass filter, and those rich oscillators. The sound oozes quality and class; the lead lines sear, and the bass is deep and squelchy. To my ears, when it was side by side with a Minimoog, the Source sounded identical, so long as the Mini was using only two oscillators. It is definitely a richer-sounding synthesizer than the Moog Prodigy or Moog Rogue -- and it's programmable!

With the current fascination for analogue monosynths, and considering the fact that some machines are fetching really silly prices, the Source is an inexpensive way to get 'that sound'. If you can track one down, it's perfect for deep, floor-shattering bass and the kind of lead line once favoured by Stevie Wonder (and more recently, Jamiroquai).

The Source's only real drawback is that you can't get very 'thin' sounds on it -- like you can from some Roland monosynths. This baby sounds mean all of the time [what, like it's lost its rattle? -- Ed]. While other synths become 'must haves' (or 'wouldn't be seen dead withs'), the Moog Source watches from the sidelines. For me, it's a very tasty piece of analogue history. So if you see one, do consider it. This synth is 'hot' -- quite literally!

Published in SOS March 1996