M5N Specifications:

3 Voltage Controlled Oscillators

1 Noise Generator

1 External Input Amplifier

1 Ring Modulator

2 Voltage Controlled Filters

2 Audio Mixers

2 Voltage Control Mixers

2 Low Frequency Oscillators

2 Envelope Generators

4 Voltage Controlled Amplifiers

1 Voltage Controlled Panning

1 Spring Line Reverberator

2 Analog Sample & Hold

2 Lag Proccessors

2 Multiples

1 Volt/ Octave interface. +5V Gate

Unit powered by 240VAC or 110VAC

Voltage Controlled Oscillators

Oscillator 1

Sawtooth, Rectangular (Square), Triangular and Sinusoidal waveform outputs. (Rectangular waveform features variable manual control of shape or pulse and has additional Pulse Width Modulation (PWM) control input socket/ slider.) Waveform output sockets include All (All the above waveforms), Rectangular, Triangular and Sinusoidal. Oscillator 1 waveform switch is 'normalised' into the VCFs 1 & 2 Audio Mixers. Oscillator 1 waveform switch is 'normalised' into the Oscillator 3 control input section. Control voltage mixing into Oscillator 1 via normalized jack sockets include the following:

Variable CV from 1V/ Octave thru 0V/ Octave to -1V/ Octave, LFO 1, LFO 2, Oscillator 2.

Oscillator 1Frequency Range is from 1 Hz to over 25 KHz. Oscillator 1 features an Initial Oscillator Frequency (Course Tuning) slider control, a Fine Tuning slider control and a 5 octave range switch- settings are 32', 16', 8', 4' and 2'.

Oscillator 1 features an Inverter switch with inverts the polarity of the output waveform- useful when used as a low frequency oscillator.

Oscillator 2

Sawtooth, Rectangular (Square), Triangular and Sinusoidal waveform outputs. (Rectangular waveform features variable manual control of shape or pulse and has additional Pulse Width Modulation (PWM) control input socket/ slider.) Waveform output sockets include All (All the above waveforms), Rectangular, Triangular and Sinusoidal. Oscillator 2 waveform switch is 'normalised' into the VCFs 1 & 2 Audio Mixers. Oscillator 2 waveform switch is 'normalised' into the Oscillator 1 control input section. Control voltage mixing into Oscillator 2 via normalized jack sockets include the following:

Variable CV from 1V/ Octave thru 0V/ Octave to -1V/ Octave, LFO 1, LFO 2, EG 1.

Oscillator 2 Frequency Range is from 1 Hz to over 25 KHz. Oscillator 2 features an Initial Oscillator Frequency (Course Tuning) slider control, a Fine Tuning slider control and a 5 octave range switch- settings are 32', 16', 8', 4' and 2'.

Oscillator 2 features a Synch switch which 'hard synchs' Oscillator 2 to Oscillator 1. This control can drastically alter the waveform timbre, or tone and will give dramatic results when swept by other sources and controllers such as Envelope Generator 1, which is normalized to Oscillator 2 via a jack socket and slider control.

Oscillator 3

Sawtooth, Rectangular (Square), Triangular and Sinusoidal waveform outputs. (Rectangular waveform features variable manual control of shape or pulse and has additional Pulse Width Modulation (PWM) control input socket/ slider.) Waveform output sockets include All (All the above waveforms), Rectangular, Triangular and Sinusoidal. Oscillator 3 waveform switch is 'normalised' into the VCFs 1 & 2 Audio Mixers. Oscillator 3 waveform switch is 'normalised' into the VCF 1 control input mixer. Control voltage mixing into Oscillator 1 via normalized jack sockets include the following:

Variable CV from 1V/ Octave thru 0V/ Octave to -1V/ Octave, LFO 1, LFO 2, Oscillator 1.

Oscillator 3 Frequency Range is from 1 Hz to over 25 KHz. Oscillator 3 features an Initial Oscillator Frequency (Course Tuning) slider control, a Fine Tuning slider control and a 5 octave range switch- settings are 32', 16', 8', 4' and 2'.

Oscillator 3 features a Stability switched potentiometer control- by using this control, one can degrade the temperature stability of the oscillator causing keyboard tracking to be slightly unstable. Some older analog synthesizers of the past are prone to having temperature stability problems, but are also known, and love for their character because of this. The Variable CV input on all the Oscillators allows for micro-tuning of that Oscillator, and also allows for reverse keyboard playing.

Noise Generator

The Noise Generator produces 3 outputs- White and Pink noise and a Slow Random signal that is very useful as a purely random modulation source- not to be confused with the Sample & Holds.

External Input Amplifier

Boosts low level signals. 1 ~ 100%

Ring Modulator

The Ring Modulator is a Four Quadrant Analogue Multiplier - providing and output that is both the sum and the difference of the input signals. Oscillators 1 & 2 are normalized to the two jack sockets and slider controls.

Voltage Controlled Filters

M5 features two of the 'classic' Voltage Controlled Filters- those being the 24dB/ Octave Transistor Ladder Low Pass and the 12dB/ Octave State Variable types.

VCF 1 is the Transistor Ladder type- Low Pass response, Self Oscillating- Sinusoidal waveform. This Filter features both Course and Fine Tuning slider controls as well as a Resonance/ Oscillation slider. VCF 1 features a pre-VCA output.

VCF 2 is the Operational Trans- Conductant Amplifier type- Low Pass, Band Pass, High Pass and Notch Responses, Self Oscillating- Sinusoidal waveform. This filter features an f C (filter cutoff) slider control and a Q (resonance/ oscillation) slider. A VCA is built into the filter network output. Both filters feature control mixers and audio mixers described below.

Audio Mixers

Both VCF1 & 2 have Audio Mixer inputs with sources normalized to them via input jack sockets and slider controls.

VCF 1 features a 5 input Audio Mixer- the normalized jack socket inputs and associated sliders are as follows:

Oscillator 1, Oscillator 2, Oscillator 3, Noise Generator and Ring Modulator.

The Oscillator inputs to the Mixer will provide a mild distortion when their relevant slider controls are pushed to the maximum setting.

The VCF 1 Audio mixer has 2 pre- VCF outputs-inverted and non-inverted, to allow for processing of the Oscillators etc elsewhere in the synthesizer or with an external synthesiser or processor.

VCF 2 features a 2 way audio mixer, with Oscillators 1 & 2 being normalized to this filter via jack sockets and sliders.

Control Voltage Mixers

Both VCF 1 & 2 have Control Voltage Mixers allowing a variety of sources to affect the timbre of the relevant filter. VCF 1 features a 5 input control mixer- the normalized jack socket inputs and associated sliders are as follows:

Keyboard CV-from 0% - 200%, i.e.- 0V/ Octave ~ 2V/ Octave, LFO 1, LFO 2, Oscillator 3 and the Noise Generator.

The VCF 1 Control Voltage Mixer has pre-VCF control outputs- these being similar to those used in the VCF 1 Audio Mixer- inverted and non-inverted outputs for control of other parts of the synthesiser and or other external voltage controlled equipment.

VCF 2 has a similar Control Voltage Mixer and features the following inputs:

Keyboard CV, LFO 1, LFO 2 and EG 2 that is also normalized via a jack socket and slider to the VCA output of that filter network.

Low Frequency Oscillators

There are 2 Low Frequency Oscillators which feature 4 waveforms, those being:

Rising Ramp, Falling Ramp, Triangular and Rectangular.

Each LFO features its own Rate control, but both LFOs are also governed by a Master Rate control, this has now been improved upon to allow 0-5V control from an external source such as a laboratory function generator.

Each LFO has it's own output, as well as being normalized into different control sections of the synth- such as the VCF control mixers, the Oscillator control inputs and the VC Panning. Each LFO also has trigger outputs- useful for triggering the Envelope Generators when using Sample & Holds.

Analog Sample & Hold

2 Sample & Hold circuits are provided on the M5- S&H 1 derives its sampling signal from the LFO 2 waveforms, this provides the user with with stepped ramps and triangles if so desired. It's speed clocked by LFO 1.

S&H 2 derives it's sampling signal from the Noise Generator, providing the user with random, stepped output voltages. It's speed is clocked either by LFO 2 or an external source. All inputs to the Sample and Hold processors are once again, normalised.

Lag Processors

The Sample & Hold processors are fed into the Lag Processors, which provide a 'slewing' function very similar to the Analog Glide used in the Keyboard CV part of the synth. Although the S&H processors are normalised to the input

Envelope Generators

The M5 is equipped with 2 ADSR (Attack, Decay, Sustain, Release) Envelope Generators.

Each Envelope Generator has 3 different timing settings- Fast, Standard and Slow.

When using the Slow setting, long envelope timing parameters, such as Attack, Decay and Release can take up to a minute and a half to go through their cycles. At the Fast setting- each of these parameters take about 2 seconds each, maximum.

Envelope Generator 1's primary function is to provide a swept 'contour' to VCF 1.

Envelope Generator 2's primary function is to sweep the output VCAs of VCF 1 & 2.

Each Envelope Generator has a +5V gate input, and both feature both positive and negate going envelope output jack sockets.

Voltage Controlled Amplifiers

There are 4 VCAs in the M5. One processes the final output of VCF 1 and has a dedicated gain control as well as a CV input jack socket to control the output of that VCA.

Envelope Generator 2 is attached to this VCA and is used to control the final out put volume.

Another VCA is used in the final output stage of VCF 2- Envelope Generator 2 also controls the final output of VCF 2 via a normalized jack socket and associated slider control.

The other 2 VCAs are incorporated into the Voltage Controlled Panning circuit described below.

Spring Line Reverberator

M5 is equipped with a long gauge spring line reverberation tank for analog reverberation effects. It features a gain input stage, which is normalized to the VCA output stage of VCF 1. There is a 'Dry/ Wet' slider control for reverberation output mix. This final mix is output to the VC Panning stage via normalized jack sockets and associated slider controls.

Voltage Controlled Panning

Voltage Controlled Panning, i.e.- stereo output is achieved via two VCAs receiving both positive and negative control voltages simultaneously- the audio input signal is derived form the normalized reverberation mix and controlled by via normalization again from LFO 1.

M5N Casing:

It would seem that these days, a popular format for analogue synthesizer design is to enclose them in cases designed for 19" rack space- this makes sense, a lot of studio equipment is designed in this format.

Most keyboard- based synths when turned into modules, are enclosed in 19" rack containers. For some modular analogue synth designers, this environment is ideal.

Pre-made cases can be obtained 'of the shelf' and involve no design and no engineering and they are cheap to buy in quantity.

Contrary to the above, having found the rack format useful before- the M3X was designed into a 6U, 19" rack enclosure- we have now broken away from this format.

The most popular vintage synthesizers were built as the designers saw fit, most had built in keyboards, and so designing for laboratory rack standard was never going to be an issue- this format really came into fashion with studio processor equipment- and rightly so- space is a premium factor in modern studios.

Common to vintage synthesizers are the general ergonomics- because there were no effective restraints on size, controls and layouts were properly organized, designers took for granted that the end user requires both finger room for control and playability, and visual space to see what's what. Some contemporary manufacturers appreciate this, some do not- preferring the convenience of working in this rather limiting rack area- the 'knock on' effect being smaller controls and a smaller visual space to work in.

But it is a cost-effective way to cram a lot of functionality into one box.

So, breaking away, discarding basic cost issues, and with a great appreciation of the synths of old, the M5 has been stylishly built into a decent sized, large working arena.

The main control panel is 30" wide, by 26" deep- this panel is positioned at an approximately 80 degree angle for maximum playability. There is a 3" 'drop' at the front of the unit to allow for a keyboard to be positioned directly in front of the M5.

The controls and sockets are generously spaced out in a logical fashion. The Jack sockets on the M5N are the 3/4" type ,quality- they are made of steel for solid, locking connections of patch cables. When it came to designing the casing, steel was chosen for both the 'chassis' and the front panel.

Mechanical Engineers will appreciate the construction of this case, which has internal 'U' bars and folds in the interior- this makes the enclosure extremely strong, robust and durable. All folds in the casing are welded shut, and then grinded down to give a pleasing 'soft' edge.

The M5N is manufactured to ROHS Compliency as well as FCC, CE compliencies and ISO 9001 Industrial QA Standards.