Module A-117 is a combination module, including a digital noise generator and an 808 source.

The digital noise generator uses random sequences of square waves (18 step shift register with multiple feedback), whose rate can go from random clicks to pure noise. The colour of the noise is very different from the analog noise produced by the A-118. In addition to a manual setting, the rate can be controlled by an external clock - eg. VCO, LFO or MIDI clock. The 808 Source aims to re-create the sort of multi-oscillator array that was used in Roland's TR-808 and 606 drum machines as the basis of the sound of the hi-hat, cymbals and cowbell. The cowbell mix uses two oscillators, and the cymbals mix six.

Merk:

Doepfer

Type:

Noise

Nummer:

A-117

Diepte:

40mm

Breedte:

8HP

Power:

20mA @ +12V, 10mA @ -12V

Module A-117-2 contains a digital voltage controlled noise generator. It produces random sequences of square pulses whose rate can go from random clicks to audible noise. The colour of digital noise is different from analog noise. The frequency of the internal clock oscillator can adjusted manually (control "Frequ.") and via an external control voltage input ("FCV") with associated attenuator. The internal clock range is about 50Hz to 40kHz. With control FCV fully clockwise the sensitivity of the control voltage input is roughly 1V/octave.

Alternatively the noise rate can be controlled by an external clock signal (e.g. from a VCO, High-Speed-VCO, LFO, midi clock). For this the "XClk" socket is provided. As soon as a patch cable is inserted into this socket the internal oscillator is turned off and the signal applied to the XClk" socket is used to generate the noise instead of the internal clock signal.

The module has two noise outputs available: a zero-symmetrical output (upper noise socket) and pure positive output (lower noise socket). The symmetrical signal is used primarily for audio applications. The positive output is used primarily for digital control applications (e.g. random envelope triggering, random clock signal or random switching functions).

Merk:

Doepfer

Type:

Noise

Nummer:

A-117-2

Diepte:

45mm

Breedte:

4HP

Power:

20mA @ +12V, 10mA @ -12V

Module A-118 is a noise and random voltage generator.

It produces three types of signal: white noise, colored noise, and random voltage. White and colored noise can be used as audio sources, and also, in conjunction with a sample and hold module, as control voltages, and the random voltage is a useful source of voltage control, especially for its low frequency content.

The A-118 gives you the ability to mix the relative amounts of Red (low frequency component) and Blue noise (high frequency component) in the colored noise output. There are knobs to control the rate of change and amplitude of the random voltage, and two LEDs indicate the state of the voltage at any one time.

Merk:

Doepfer

Type:

Noise

Nummer:

A-118

Diepte:

40mm

Breedte:

8HP

Power:

20mA @ +12V, 10mA @ -12V

Module A-118-2 generates the signals white noise, colored noise, continuous random voltage and stepped random voltage.

The noise signal is generated 100% analog by amplification of the noise of a transistor. White and colored noise are usually used as audio sources. The random voltages are normally used as control voltages (e.g. for filter frequency or any other voltage controlled parameter).

The A-118-2 gives you the ability to mix the relative amounts of Red and Blue noise (low/high frequency component) in the colored noise output.

For the continuous random voltage the rate of change (Rate) and amplitude (Level) of the random voltage can be adjusted. The continuous random voltage is used as source for the S&H/T&H unit. The type of operation can be set to S&H (sample and hold) or T&H (track and hold). When T&H is chosen the output signal follows the input signal as long as the Clock input is "high". As soon as the clock signal changes to "low" the last voltage is stored. When S&H is chosen the input signal is sampled at the rising edge of the Clock signal. For the Clock signal a "digital" signal (e.g. Clock, Gate, rectangle output of an LFO) is required. Dual color LEDs are used to indicates the continuous and stepped random voltages.

Controls:

• Blue: share of the high frequencies in the the colored noise output
• Red: share of the low frequencies in the the colored noise output
• Rate: rate of change of the continuous random voltage
• Level: amplitude of the continuous random voltage
• TH/SH: switches between T&H und S&H

Inputs and outputs:

• RND: continuous random voltage output (with LED display)
• TH/SH: stepped random voltage output (with LED display)
• Clk: Clock input of the S&H/T&H unit
• C Noise: colored noise output
• W Noise: white noise output

Merk:

Doepfer

Type:

Noise, Sample and Hold, Random

Nummer:

A-118-2

Diepte:

40mm

Breedte:

4HP

Power:

20mA @ +12V, 20mA @ -12V