The Rockman Sustainor is the heart of the classic Rockman rig and one of the most complex and distinctive Rockmodules ever produced. Developed over several years by a dedicated team of engineers, the Sustainor combines an immediately recognizable sound signature with an exceptionally broad range of tonal possibilities.

Considered one of the earliest high-end analogue amp simulators, the Sustainor goes far beyond the traditional concept of a guitar preamp. Its architecture combines adjustable gain stages, volume controls, filters and several advanced circuits specifically developed to expand the possibilities of the original Rockman headphone amplifiers.

Professional evolution of the Rockman amp simulation

The foundation of the Sustainor is the amp simulation developed for the original Rockman headphone amplifiers. While those units were based around four preset sounds, the Sustainor represented a professional evolution of the same basic concept.

The design introduced adjustable gain stages, volume controls and filters, together with several more sophisticated circuits. Among these are the Smart Gate, the Autoclean and the Phase Notcher, which significantly expanded the possibilities of the original Rockman architecture.

The original Rockman headphone amplifier was created by Tom Scholz and released in 1982. SR&D subsequently continued improving the design between 1982 and 1986, making incremental circuit adjustments before the Sustainor emerged as a professional development of the concept.

Development and commercial release

Development of the Sustainor required several years of engineering work. The commercial Rockman Sustainor was released in January 1986, together with the Rockman Chorus/Delay.

Like other Rockman products, the Sustainor continued to evolve throughout its production history. The first commercial units corresponded to REV03, while the final commercial release in 1989 reached REV09.

This continuous development is an important part of the history of the Sustainor and helps explain the differences between earlier and later examples.

Blue Face and White Face versions

The early Sustainors are commonly referred to as 100 or “Blue Face” models because of their blue front-panel logo. Their rear panels were stamped 100, although this designation was used across Rockmodule enclosures and therefore represents an enclosure type rather than a unique Sustainor version.

Almost 9,000 Sustainors were sold in 1986. Around February or March 1987, at approximately serial number 10000, the rear panel changed to the 100A designation while the blue logo remained in use. These 100A units are considered transitional Blue Face models before the later logo change.

In October 1987, Rockmodule front panels received a white logo instead of the original blue one. At the same time, the Sustainor received a new rear-panel designation: 200 instead of 100.

The front panel was also slightly modified, leading to the commonly used Sustainor 200 or White Face designation. The 200 should not be considered a completely different product, but rather a continued development of the original 100 design.

Complex analogue architecture

The Sustainor is considerably more complex than the amp simulation circuit used in the original Rockman.

The original Rockman amp simulation was based on only 6 operational amplifiers controlled by a single mechanical switch. The Sustainor, by comparison, contains 28 operational amplifiers together with an extensive network of mechanical and J-FET switches.

This considerably more sophisticated architecture provides the foundation for the Sustainor’s extensive tonal flexibility and its characteristic analogue processing approach.

Smart Gate, Autoclean and Phase Notcher

Three of the most significant developments introduced with the Sustainor are the Smart Gate, Autoclean and Phase Notcher circuits.

The Smart Gate provides noise reduction, while Autoclean represents one of the Sustainor’s distinctive signal-processing features. The Phase Notcher provides a 4×12 cabinet simulation, contributing to the amp-simulation architecture that distinguishes the Sustainor from a conventional guitar preamp.

Together with the adjustable gain stages, volume controls and filters, these circuits form an unusually sophisticated analogue guitar-processing system.

As a result, the Rockman Sustainor became far more than a simple preamp, offering a highly developed analogue approach to guitar amplification simulation that remained distinctive decades after its introduction.

In short, the Rockman Sustainor combines a complex analogue architecture, adjustable gain and filtering, Smart Gate, Autoclean and Phase Notcher circuits with a long production history spanning multiple revisions from REV03 through REV09.

Technical Specifications

• Model: Rockman Sustainor
• Type: Analogue guitar amp simulator / preamp
• Design: Analogue
• Operational Amplifiers: 28
• Switching System: Mechanical and J-FET switches
• Gain Stages: Adjustable
• Volume Controls: Adjustable
• Filters: Adjustable
• Smart Gate: Yes
• Autoclean: Yes
• Phase Notcher: Yes
• Cabinet Simulation: 4×12
• Early Version: 100 / Blue Face
• Transitional Version: 100A / Blue Face
• Later Version: 200 / White Face
• Early Commercial Revision: REV03
• Final Commercial Revision: REV09
• Commercial Release: January 1986
• Production Period: 1986–1992
• Production Quantity: Over 21,000 units
• Manufacturer: Rockman / SR&D