Discrete OTA VCF
The text below is from the description page for the MOTM-440 Discrete OTA Voltage-Controlled Lowpass Filter with VC Resonance. The E440 is an euro version of this module. While not all features between the two are the same, I thought some of the basic features and history of the module would be of interest. http://www.synthtech.com/motm440.html
"You have probably heard of the SSM2040 filter chip, used in the Prophet 5 Rev. 2 synth, the Voyetra 8, and others. Although short-lived, the SSM2040 filter had a unique sound different from a Moog, ARP or other 4-pole lowpass. Why? The design used a clever discrete OTA gain cell.
The MOTM-440 offers an updated SSM2040 architecture using matched NPN/PNP pairs and features a switch that adds a second audio feedback path to boost bass response at higher Q levels. This makes the filter "growl and rumble" even more! In addition, voltage-controlled Q allows for more sweeping effects. Three audio inputs and three CV inputs make the MOTM-440 the killer lowpass filter in your system. The internal gain structure is such that over-driving the filter is now possible (unlike the Prophet 5) to get even more nasty sounds. Did we mention it self-oscillates at high Q?
So order a MOTM-440 filter for a fraction of the price of a P5 Rev. 2, but without the worry of obsolete parts!"
From Web site:
The E440 is based on the 5U MOTM-440 filter with additional features such as separate outputs for each filter slope and an input Drive control.
You have probably heard of the SSM2040 filter chip, used in the Prophet-5 Rev 2, Voyetra 8, and others. Although short-lived, the SSM2040 filter had a unique sound different from a Moog, ARP, or other 4-pole lowpass filters. Why? The design used a clever discrete OTA gain cell that responds beautifully as additional gain is added to the input signal.
The E440 provides three simultaneous filter slopes: 2 Pole (12dB), 3 Pole (18dB), and 4 Pole (24dB) for selective timbral shaping. Voltage control of filter resonance (rarely found on other filters) is also available.
This Module is currently available.$300 submitted Oct 13th 2012, 08:32 by H_wig | last Change Jul 31st, 09:07 by analogdarkside
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