Sub-modules are small, densely packed, hybrid or discrete sub-assemblies that plug in to the main board of the module/synth somewhat similar to the large microprocessor chip in a conventional computer. These are the core circuits used in all ARP synthesizers. Earlier ARP synthesizers use sub-modules that were encapsulated in thermally conductive epoxy

The CMS 4000 series replacement sub-modules for the ARP series 2000 synthesizers are preferred by many professional recording artists across the country. Uncompromising accuracy and a fanatical approach to audio fidelity result in replacement sub-modules that surpass the originals in construction and performance.

Included in the line, is our world famous replica of the 4012 filter used in early 2600's. Many of our 2600 filters are being used in famous recording studios and large film production facilities. This direct replacement features lower signal to noise, lower distortion, faster slew rate than the original, but still maintains the original factory design. This is accomplished by using modern, high quality, low noise, ultra-linear components.

Recently added to the line, is the 4040 and 4080 series. These are discrete, high fidelity, analog processing sub-modules designed for the CMS 9000 modular system, that are fully compatible and interchangeable with ARP 2600 sub-modules. These new CMS designed circuits have a distinctive vintage sound. Painstaking research in vintage differential transistor design, and research on the current revival of high end discrete preamplifier design, culminated in the creation of five new sub-modules with remarkable aural qualities. Please go to the new 2nd generation sub-modules page in the DiscreteSynthesizers section for more information on these sub-modules.


MODEL 4012cx



Shipping is now available to Europe

see the green area below for shipping details



updated: 09/12/2014


4001 / 4002 EXPONENTIAL MODULES (for the ARP 2500) - 79.00

Rev-F features improved thermal properties - excellent tracking, military grade components. Special order.


4005cx VCA MODULES (for the ARP 2500 multimode filter) - 89.00

Please specify: 1P, 2N OR 3P. These improved discrete VCA modules exhibit much better control voltage feed-through specs than their ARP predecessors. Special order.


4009 HIGH IMPEDANCE OP AMP (for the ARP 3604 keyboard) - 48.00

This module is for the memory circuit in the early 2600 keyboard controller. Low profile design facilitates installation and calibration.


4012cx 24db LOWPASS VCF - (for the ARP 2600 and Soloist) - 399.00

The original 2600 filter is now available from CMS. The 4012 is ARP's hybrid version of the 4 pole ladder filter similar to the filter used by Moog. Use as a direct replacement for the post 1975, chip filter (4072), or as a solution to the unstable behavior of the original 4012s, (Symptoms include: clicking, chirping, short-wave noises, loss of gain and high end when the filter Fc is high). With no alterations in the original circuit design, this module features improved construction techniques over the original to guarantee click free, stable operation all the way up to 35khz. Low noise, precisely matched, ultra-linear transistors ensure an unmistakable vintage sound. Tested to more stringent standards than original factory test procedures. Directly replaces 4012, 4013 and 4072 modules. The 4012cx installation Kit can be installed by a competent tech. Comes compete with easy installation instructions. Free installation and calibration when installed at CMS.


4014cx BALANCED MODULATOR (for the ARP 2600 or 2500) - 225.00

Built to exact factory specs using premium grade components. Improved high slew rate output stage.

We also offer a 4014 adapter board for older 2500 Ring Mod replacements. Special order part # 4107.


4015 SAMPLE AND HOLD (for the ARP 2600) - 189.00

Built to factory specs with ultra low drift components.


4019cx VCA MODULE (for the ARP 2600) - 225.00

Improved components and better power supply isolation result in lower distortion and a much faster transfer function. Built from original ARP blueprints and fully tested beyond factory parameters. Very transparent compared to original 4019's


4020 A.D.S.R. MODULE (for the ARP 2600) - 179.00

Built to exact factory specs. Uses discrete transistors for reliable, high speed performance.


4022 NOISE GENERATOR (for the ARP 2600) - 45.00

A genuine analog white noise source. Tested using factory procedures for proper spectral density and stability.


4023 12db LOWPASS VCF - (for the ARP Odyssey 2800) - 279.00

The original 2800 filter is now available from CMS. This filter is a 12 Db 2nd order lowpass filter based on the famous ARP 2500 multimode filter.


4027-1 PRECISION VCO (for the ARP 2600, Soloist , Little Bro & Explorer) - 189.00

Built to exact factory specs, and tested using original factory criteria. We use only OEM parts to assure stable pitch and uniform tracking with the other ARP VCO's in your system. Directly replaces: 4011, 4017, 4027, and 4027-1 modules. Beware of cheap imitations using parts "as close as possible".


4072 LOWPASS FILTER (for the ARP 2601) - 299.00

Genuine OEM unit. Upgraded to 28Khz and re-tested to factory specs. Also features an improved output stage. Guaranteed to be temperature stable and free of control voltage feed-through. Limited availability.


4075 LOWPASS FILTER (for the ARP Odyssey II, and Avatar) - 275.00

Genuine OEM unit. Upgraded to 28Khz and re-tested to factory specs. Guaranteed to be temperature stable and free of control voltage feed-through.




All prices are USD.


At this time, we only accept: personal check or PayPal.

Email CMS here to get the mailing address to send your check.

PayPal: Please use this email address: for all PayPal payments. Please pre-pay or add 3% to cover the Paypal charges. Overseas customers paying with PayPal must add 4% to cover the PayPal charges.



USA Shipping charges: 1 sub-module - 15.00 / 2 sub-modules - 18.00. / 3 sub-modules - 20.00 Add 7% sales tax for GA residents only.

We now offer 2 flat rate shipping options for shipping 1-2 sub-modules to Europe.

1. Shipping / handling for USPS first class - $20.00 USD. - (no tracking, no insurance, no delivery confirmation)

2 .USPS International Priority with tracking and insurance:

United Kingdom - $35.00 USD.

Europe - $49.00. USD.

Email CMS for shipping rates on multiple sub-modules.


All CMS sub-modules are guaranteed for 1 year against defects in materials and workmanship. Faulty installation or diagnosis is not covered. Damage through misuse, sloppy installation or static shock is not covered. Installation of these sub-modules requires a competent and experienced tech. Prices and availability subject to change.


Technical Notes:

Most sub-modules are soldered in place at the factory. Removal and installation of sub-modules requires a competent and experienced tech.

Encapsulated OEM ARP sub-modules that are defective are not repairable. Warning! - burning, melting, grinding or chemically dissolving the potting epoxy is extremely hazardous to your health.

In all cases, DO NOT CLIP THE SUB-MODULE PINS! - if you do, you will render the sub-module un-testable and possibly damage your main board.

phone: 912-727-2195