1004 VCO data sheet

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Phone: 912-727-2195

©2020 Phil Cirocco


			MODULE 1004 - THE PEARLMAN OSCILLATOR

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		CMS/DISCRETE SYNTHESIZERS has faithfully reproduced the world famous ARP 1004 oscillator invented by Alan Pearlman himself, from the ARP 2500 system in a high quality version of the Euro-Rack format. Alan Pearlman designed this revolutionary temperature compensated oscillator circuit in 1969 to offer a high quality voltage controlled oscillator that holds pitch and scale in a recording studio environment. CMS has extensive knowledge and experience building and repairing these classic sounding, unique oscillators. We have taken this expertise and applied it to the Euro-Rack format. This is the exact VCO circuit used in all 2500 oscillator modules produced by ARP from 1970 to 1977 including modules 1004, 1004R, 1004P, 1004T, 1023, and 1045. It was a huge engineering challenge to faithfully reproduce the massive and complex VCO circuit. We also updated the design and reduced the size down to Euro Rack format with no compromises in design, components and audio quality. Additionally, we crammed the unique T-mixer circuit from the original ARP 1004T module into our tiny euro rack module. The T-mixer mixes wave-forms, 5 positive and 5 negative, in different combinations using the 5, 3-position miniature toggle switches, to attain some unusual wave shapes, especially for a vintage oscillator. See the demo video below.

		FEATURES: High quality construction and top shelf components, Switchcraft jacks, Alps attenuators. CMS engineering used in many professional recording studios across the USA and Europe. Main frequency control pot features an extra large geometry "virtual infinite resolution" potentiometer for accurate control of frequency. Integrated T - mixer section has also been accurately reproduced to facilitate unusual waveforms. 3 control voltage inputs. 1 fixed at 1v per octave and 2 more with attenuators. 1 Pulse Width Modulation input with attenuator. Easy to understand flowchart front panel graphics facilitate operation. The brushed aluminum front panel is made of a special material that has the image impregnated into the aluminum surface. It will not fade over time or wear off from finger action. Additional auxiliary output panel is available with 5 individual waveform outputs and 1 additional T-mixer output.

	SEE OUR MAIN EURO-RACK PAGE FOR CURRENT PRICES AND AVAILABILITY

CMS Module 1004 is a functional circuit package designed for use in Euro-Rack electronic music synthesizers. In honor of the inventor, Alan Pearlman, we have recently renamed it "The Pearlman Oscillator".

The CMS 1004 Oscillator Module is a voltage controlled waveform generator. The module contains both a basic 1004 oscillator and a unique bipolar waveform mixer. Sine, triangle, square, saw tooth, and pulse waveforms can be combined in numerous and unusual combinations. Five center-off miniature toggle switches allow any of these waveforms or their inverses to be selected and mixed to the output. When more than one waveform is selected, the output is the instantaneous average of the selected waveforms. The CMS 1004 is particularly recommended for generating unique audio signals.

The output frequency range is from .03 Hz to 16,000 Hz in two ranges (1004L) without external control voltages, and the control voltage range is 10 octaves on each range. Control signals may be either positive or negative, provided that the sum of the control voltages does not drive the oscillator frequency beyond the above limits.

A coarse panel adjustment knob permits setting the zero-control-voltage frequency. A fine adjust knob with a + 1/2 octave range is provided for accurate tuning.

The frequency modulation input on the left of the module is a fixed sensitivity input: 1 volt/octave. The two center frequency modulation inputs (in positions 2 and 3) are associated with two attenuators directly above the inputs. When the attenuators are rotated fully clock-wise, the input sensitivity is 1 volt/octave. These controls are used to adjust frequency modulation depth.

Another control input, designated PWM, is a pulse-width modulation control input, which is also provided with a panel-knob-actuated modulation depth control. In addition, another panel-knob control (PW) permits manual adjustment of pulse width.

The input impedance of the control inputs is 100 Kohms minimum over the frequency range of the oscillator. The output impedances of the CMS 1004 waveform generator section is 1000 ohms.

The dedicated v/oct input is calibrated to a 1V per octave scale.

Some things not included in the CMS 1004 compared to the original ARP1004:

An optional LFO mode switch is now available. Please specify module 1004L. This enables the user to produce unique and complex LFO patterns using the T-mixer and it's respective output.


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	Demo video of the 1004 output viewed on a CRT scope.

		Synchronization of the 5 output waveforms

ELECTRICAL SPECIFICATIONS: ELECTRICAL SPECIFICATIONS

OUTPUTS

Frequency: 31Hz— 16KHz without external inputs or .016 Hz to 33Khz with external voltages applied.
Sine: -4 volts to +4 volts P-P, inverted phase sine
Triangle: —4 volts to +4 volts P-P, inverted phase triangle
Sawtooth: 0 volts to +8 volts P-P., 0 volts to -8 volts P-P.
Square: 0 volts to +8 volts P-P, 0 volts to -8 volts P-P.
Pulse: 0 volts to +8 volts P-P, 0 volts to -8 volts P-P.

Output Impedance: 1 Kohm.

INPUTS

Frequency Modulation: 1 volt/octave. Pulse Width Modulation: 10%/volt. Input Impedances: 100 K.

CONTROLS

Frequency Range: (31 Hz-16 KHz).
Frequency, Coarse
Frequency, Fine: +1 octave.
Frequency Modulation Depth (2)
Pulse Width: 0-100%
Pulse Width Modulation

LONG TERM FREQUENCY DRIFT

Ambient 50°F to 90°F, drift is typically 0.1% per hour.

POWER REQUIREMENTS:

+ 12 volts @50 ma, regulated to +0.1%.

SIZE SPECIFICATIONS:

MODULE DEPTH: 1.75 inches

MODULE WIDTH: 14HP




	SEE OUR MAIN EURO-RACK PAGE FOR CURRENT PRICES AND AVAILABILITY