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. Later issue ARP synthesizers have un-encapsulated boards in place of the encapsulated modules that can be repaired here at CMS.

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.

2 other notable CMS sub-modules are the 4019CX Current Mirror Voltage Controlled Amplifier and 4014CX Current Mirror Balanced Modulator. We spared no expense in the design and manufacture of these critical audio elements of the 2600. These sub modules feature significantly improved audio fidelity when compared to the originals or any other VCA and balanced modulator circuit available.

 
SERIES 4000 REPLACEMENT SUB-MODULES
 

MODEL 4012cx

IMPROVED REPLICA VCF
 
 
 
 
 
       
 

REPLACEMENT SUB-MODULES CURRENTLY IN PRODUCTION

updated: 6/19/2024

 

4001 / 4002 EXPONENTIAL MODULES (for the ARP 2500) - 89.00

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) - 64.00

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

 

4010CX VCA MODULE (for early versions of the ARP 2600) - 249.00

The original VCA used in early versions of the ARP 2600 and the Blue Marvin 2600 is now available from CMS. This module differs from other 4000 series sub-modules because it is in a 1 x 2 inch format. You must have a 1 x 2 inch hole pattern in your 2600 to accept this sub-module.

 

4012CX 24db LOWPASS VCF - (for the ARP 2600, 2700 & CMS 2607) - 399.00

The original 2600 filter is now available from CMS. The 4012 is ARP's hybrid version of the 4 pole ladder filter somewhat similar to the filter used by Moog but there are significant design and audio differences. 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, 2500, CMS 2607) - 225.00

Built to exact factory specs using premium grade components. Improved high slew rate output stage and input 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, CMS 2607) - 189.00

Built to factory specs with ultra low drift components.

 

4019CX VCA MODULE (for the ARP 2600, CMS 2607) - 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

Second generation envelope generator for the 2600. Also coined by the factory as the "simplified envelope generator". Built to exact factory specs. Uses discrete transistors for reliable, high speed performance.

 

4022 NOISE GENERATOR (for the ARP 2600, CMS 2607) - 75.00

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) - 229.00

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

 

NEW - 4027CX DISCRETE VCO - (for the ARP 2600P, 2601 & 2700) - 279.00

There were 2 distinctly different VCO circuits used in ARP 2600 production.

The first generation 2600 VCO includes the 4011, 4017 and 4027 oscillators. Some people, including myself, prefer the sound of the first generation VCO. The first generation 2600 VCO is a more complex, purely discrete circuit, designed by Dennis Colin.

Now the original first generation VCO circuit is available from CMS as the CMS 4027CX sub-module. This new improved version by CMS features superior sound quality, precision tracking and solid temperature stability. The CMS 4027CX can be installed in all versions of the ARP 2600 and 2601. You will hear the difference.

 

NEW - 4027CX ADAPTER BOARD - (for the ARP 2600P, 2601) - 25.00

This adapter board is required to install the CMS 4027CX in later models of the 2600P and 2601s that are missing the high frequency tracking trimmers on the main VCO board and front panel.

 

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

This is the second generation VCO used in all ARP 2600s made from August of 1972 to 1980. Designed by Phil Dodds. 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: 4017, 4027, and 4027-1 modules. Beware of cheap imitations using parts "as close as possible".

 

NEW - 4035CX 24 Db LOWPASS FILTER - (for the ARP Odyssey II, and Avatar) - $229.00

CMS has come up with a great sounding filter for the ARP Odyssey 2!

The 4035 filter was the second version filter used in the ARP Odyssey. It is ARPs version of the Moog ladder filter for the Odyssey.

After years of development and listening tests, we have come up with a much improved version of the 4035. It exhibits significantly lower noise and better low end response compared to the original without any changes to the original circuit design. It also has a spectacular sound quality.

The original ARP 4035 was also prone to significant gain loss when the filter was all the way open. The gurus at CMS have eliminated this annoying defect resulting in a more powerful sound. Guaranteed to be temperature stable and free of control voltage feed-through.

There is more! Now you can have ARPs version of the Moog ladder filter installed in your Odyssey 2 without giving up your original filter! Or vice versa. Please check out the new 2829 secondary filter for the ARP Odyssey 2 .

 

NEW - 4041 A.D.S.R. MODULE (for the ARP 2600, CMS 2607) - 225.00

Built to exact factory specs. This is the exact envelope generator circuit from the ARP 2500 in a sub-module form for use in the 2600. It was used in very early 2600s as the ADSR module. It uses discrete transistors for reliable, high speed performance. Use as a drop in ADSR replacement upgrade for your 2600. Includes an additional negative output pin that can be wired to a front panel output jack.

 

4072 LOWPASS FILTER (for the ARP 2600) - 299.00

Second generation low pass filter for the ARP 2600. 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) - 225.00

Third generation filter used in the ARP Odyssey 2 and Avatar. Genuine OEM unit. Upgraded to 28Khz and re-tested to factory specs. Guaranteed to be temperature stable and free of control voltage feed-through.

 

 
 
   
     
   
Ordering:

All prices are USD.

Payment:

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

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

PayPal: Please use this email address: filter@discretesynthesizers.com for all PayPal payments. Please pre-pay or add 3.5% to cover the Paypal charges. Overseas customers paying with PayPal must add 5% to cover the PayPal charges.

 

Shipping:

USA Shipping charges: 1 sub-module - 18.00 / 2 sub-modules - 21.00. / 3 sub-modules - 23.00 Add 7% sales tax for GA residents only.

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

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

2 .USPS International Priority.

United Kingdom - $35.00 USD no insurance, $45.00 USD with insurance.

Europe - $49.00. USD no insurance, $59.00 With insurance.

Australia - $43.00 - no insurance, $55 with insurance.

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.

  
     
     
     
 
 
 
e-mail: filter@discretesynthesizers.com
phone: 912-727-2195