CMS/DISCRETE SYNTHESIZERS has faithfully reproduced the world famous ARP 1047 multimode filter from the ARP 2500 system in a high quality version of the euro-rack format.

CMS has extensive knowledge and experience building and repairing these classic sounding, highly resonant filters. We have taken this expertise and applied it to the euro-rack world. A world somewhat lacking in high fidelity. We are on a mission to change all that.

Don't let the compact size of the 1047 fool you. This unit is an audio monster. The low end response is remarkable even on the band-pass and high-pass functions. The sonic clarity, high end response and resonant sizzle, sets this filter apart from all the other filters made today. The high-pass response actually has the ability to resonate bass and sub bass audio signals significantly, producing some monster bass sounds for the dance floor, especially when used in series with a 24db low-pass filter.

The 1047 multimode filter is the module that gives the ARP 2500 it's distinctive sound more than any other 2500 module by far. The CMS 1047 is a "dead ringer" as far as audio performance and sound, compared to the original. Actually our version has lower noise specs due to better design, quality components, and no matrix switches.

Using the 1047 high-pass response in series with the 1066 low pass function really captures the classic ARP 2500 sound. You can now realize this sound in your studio with the 1047 and 1066 from CMS. The 1067 VCA is also recommended.

If you want to reproduce the sound of the ARP 2500 exactly, check out our other 1000 series modules that are available from CMS. They are all based on the ARP 2500.

FEATURES:

This unique and complex circuit utilizes 3 discrete ARP / Wilson current mirror VCAs to produce it's distinctive and highly resonant sound.

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.

3 control voltage inputs. 1 fixed at 1v per octave and 2 more with attenuators.

1 Voltage controlled resonance input with attenuator.

Easy to understand flowchart front panel graphics facilitate operation.

CMS Module 1047 is a functional circuit package designed for use in Euro-Rack electronic music synthesizers. In honor of the late inventor, Dennis Colin, we have recently renamed it "The Colin Multimode Filter".

The CMS Module 1047 is a functional circuit package designed for use in Euro-Rack electronic music synthesizers. This unique and complex circuit utilizes 3 discrete ARP / Wilson current mirror VCAs to produce it's distinctive and highly resonant sound. The new improved front panel is now 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.

The unit consists of a highly resonant filter with voltage controlled frequency and resonance, and provides high pass, band pass, low-pass, and notch outputs. The filter is capable of providing a wide variety of formant shaping and tonal modulation. The band pass response is that of a natural acoustic resonator, and is most useful in synthesizing instrumental timbres. In addition, the high degree of stable resonance and frequency tracking accuracy attainable enables the filter to perform precise, narrowband spectrum analysis of audio signals.

The center frequency of the band pass output is the cutoff frequency of the high pass and low pass outputs, and is referred to as "Fc". Fc may be set by the frequency knob over the range of 16 Hz to 16 KHz. Control signals applied to any Fc input will change the center frequency from the knob setting by 1 octave per volt when the knob above the control input is at maximum. Control signals from the individual inputs are summed with the Fc knob controls, and may be positive, negative, or audio.

With the RESONANCE (Q) knob at minimum:

The band-pass output has a gain of 0.5 at Fc and attenuates 6 db per octave above and below Fc.

The high pass output has unity gain from Fc to 20 KHz and attenuates 12 db per octave below Fc.

The low pass output has unity gain from DC to Fc and attenuates 12 db per octave above Fc.

The notch output has flat response everywhere except for a deep (40 db) notch at a frequency determined by the NOTCH FREQ knob. With this knob set to 12 O'clock, the notch occurs at Fc. NOTE: The notch output is effective only at low Q.

As the RESONANCE (Q) knob is turned up, a resonant peak occurs at Fc in all four outputs, except in the notch output when the notch frequency is at Fc. The gain at this peak is numerically equal to the "Q", and the 3 db bandwidth of this peak is equal to Fc/Q. Thus, as Q is varied from 0 to 10, the bandwidth varies from 2 Fc (2 octaves) to Fc/512 (1/32 of a semitone).

Operational tip: When using high resonance, the audio input control may have to be turned down to prevent overload. Try backing off on the input signal when using resonance. The unit has a good signal to noise ratio, so you don't have to run the input on "10" all the time, except when there is no resonance. The more you add resonance, the more you should back off the input signal. You will get a better sounding resonance also.

The Q may be controlled by external signals. The Q control characteristic is exponential; that is, each volt applied to a "Q" input doubles the Q when the input knob is at maximum.

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

ELECTRICAL SPECIFICATIONS:

CENTER FREQUENCY (Fc): 16 Hz to 16 KHz, voltage controlled.
BANDPASS RESPONSE: Single pole resonator, 6 db per octave.
RESONANCE (Q):1/2 to 512 (0 to 54 db peaking at Fc), voltage controlled.
BANDWIDTH (3 db): 2 octaves to 1/32 semitone.
HIGHPASS AND LOWPASS RESPONSE: 12 db per octave cutoff at Fc, with same resonant peak at Fc as in Band pass Response.
NOTCH RESPONSE: Resonant peak at Fc as in Band pass Response, plus notch at frequency determined by NOTCH FREQ/Fc control.
With this control at 12 o'clock, response is flat except for notch at Fc.
NOTCH DEPTH: > 40 db.
NOTCH WIDTH (3 db): 2 octaves to 1 semitone.
CONTROL INPUT RANGE: ± 10v maximum.
INPUT IMPEDANCE: 50 K ohm minimum.
Fc CONTROL CHARACTERISTIC: 1 octave per volt; at OV, Fc is equal to the frequency knob setting.
Q CONTROL CHARACTERISTIC: 1 volt doubles Q; at OV, Q is equal to resonance (Q) knob setting.
AUDIO INPUT RANGE: ± 10 v maximum.
AUDIO INPUT IMPEDANCE: 50 Kohm minimum.
AUDIO OUTPUT IMPEDANCE: 1 Kohm.
POWER REQUIREMENTS: ± 12 volts @ 50 mA, regulated to+0.1%.

SIZE SPECIFICATIONS:

MODULE DEPTH: 1.75 inches

MODULE WIDTH: 14HP

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