Rockman Sustainor

Production: Approximately 21,120 units (1985-1994)
Suggested list price: $349.95
Dealer price: $210.00

The Rockman Sustainor Preamp Module was designed by a select team of Electronic Engineers located in various parts of the country. Research and development took nearly 4 years to complete. The goal was to produce a unit that would give Scholz precise sound control for the Boston concert stage. Used exclusively by Boston in concert with only one known exception of a modified XPR (Superhead) in use at the Fiesta Bowl. This preamp has been the heart of the Boston live sound since its inception.

Production Model 100

The first Production Model 100 Sustainors were released in January 1986 (eg. #1,451 with IC dates of 5th week 1986). Specific dates regarding early models are difficult to determine because of the absence of the production date on the rear panel. Known to collectors as the "Blue Face" Sustainor because of the blue Rockman Sustainor font along the bottom of the faceplate. Approximately 11,000 Model 100 Sustainors where produced. More difficult to use effectively than later models.

Production Model 100A

The second Production Sustainors were the Model 100A. Best information at this time indicates the Model 100A Sustainors were made for approximately 5-6 months starting in April of 1987. The first known Model 100A is serial 10,811. The Model 100A still carried the blue Rockman Sustainor font logo on the bottom of the faceplate. Approximately 2,000 Model 100A Sustainors were produced. Perceived signal changes in this model compared to its predecessor are subtle. It was evident that the Sustainor would still need an extensive overhaul. There are several "Blue Face" Sustainors on the Boston Stage. These could be Model 100 or Model 100A Sustainors. They are used by everyone except Scholz in his Lead setups. Pihl has three (of four) in his Lead setups available for use but he prefers a particular later unit.

Prototype Model 200

The first Prototype Model 200 Sustainors were developed before October 1987. One would suspect development of these prototype Model 200s took a great deal of time as these units were a significant improvement. Faceplates were unique with the blue scripted Rockman Sustainor font (white for production Model 200 units), a slightly different arrangement of graphics, and a pair of visible Overdrive Threshold LEDs. SR&D Prototypes also carried a pair of unique decals with an additional serial number. The highest know prototype serial number is six (6). Likely a small batch of 6, 10 or perhaps dozen units were prototype development units.

Production Model 200

First Production Model 200 Sustainors were released in Sept 1987. The last known unit # 21,120 was made in 1992. No units made in 1993-1994 have appeared as of this date. It is unclear if excess 1992 Sustainor inventory was sufficient to fill the dwindling demand during these last 2 years or if units in very small quantities were manufactured to fill remaining orders. Perhaps SR&D was not capable of producing more units. Approximately 5,700 early Model 200 Single Integrated Chip (IC) Sustainors were produced. All model 100, Model 100A and early Model 200 Sustainors were Single IC units.

The Model 200 Sustainor represented the first major Engineering Revision. Compressor modifications and improved distortion filtering made the unit much quieter and less prone to feedback at loud volume levels. Easily identified by the newer white Rockman Sustainor font along the bottom of the faceplate which matched the new additions to the Rockmodule lineup. While the companion Rockmodules went though about three (3) revisions each, the Sustainor was practically in a constant state of revision. This was a direct result of Scholz's involvement seeking improvement. Amazingly, the Model 200 Sustainor had reached at least Revision 9A in 1992 with multitudes of sub-revisions and Engineering Change Notifications (ECN). This model was used by both Scholz and Pihl on the Third Stage World Tour.

Non-Production REV 19 and REV 20

Within the Model 200 build some non-production Sustainors were made. Bob Cedro designed and developed Scholz's personal Models REV 19 and REV 20. Presumably this was by request from Scholz for improvements. Just a few handfuls of Production Model 200 Sustainors were pulled and modified. It is assumed that Scholz and Pihl hand picked a given amount of these modified units for Stage and Studio use and the remainder were sold to specific customers.

REV 19 and REV 20 units are most easily identified by their PRE-TREB input control instead of the stock PREAMP-GAIN input control. Both the REV 19 and REV 20 had stock rear panels printed with the typical Model 200 notation. Only the REV 20 had a unique faceplate with Pre Treb in painted font and a 1989 copyright date under the power switch. The REV 19 used a production model 200 faceplate with the 1985 copyright date and a glued paper Pre Treb label. The first known REV 19 appears on March 17, 1989 (serial 18,987). Two (2) REV 19s are known to exist one with a black pre treb label and one with a blue pre treb label. The next issue was the REV 20. The first known unit appears on April 20, 1989 (serial 19,191). Thirteen (13) REV 20s are known to exist including Scholz's and Pihl's.

There are four (4) major differences in the REV 20 and REV 19 units compared to the production units at that time.

  1. The Auto Clean really functions as intended.
  2. Pre Treb input control functions as a bass defeat tone control. Higher setting result in less bass input to the compressor. A 10K resistor was installed to hold the preamp gain constant.
  3. There was a significant boost of the 11K-12K frequencies in the Distortion and Edge modes.
  4. "Lead Leveler®" known internally (SR&D) as the "Tom Circuit" with the "piggy back" Double IC. Functional only in the Distortion and Edge modes (to avoid compressor breathing), it speeds up the recovery time of the compressor within the window of high to medium compression. This is desired when playing hammer-ons, pull-offs and quick picked notes. This is accomplished by letting the compressor recover quickly from the attack of the previously played note.

Late Production Model 200 Double IC Sustainor

Late Production Model 200 Sustainors benefited from the development of the REV 19 And REV 20s. The "Lead Leveler®" Double IC Revision was integrated into Late Production Model 200 Sustainors. The first known unit serial number 19,291 was made on May 12, 1989. Best information indicates a steady flow of Double IC Model 200 Sustainors starting in mid June of 1989 beginning with serial number 19,571 however there could be exceptions.

The Double IC "Lead Leveler®" Model 200 cannot be identified from its exterior appearance. Early Model 200 Sustainors were scripted with "Gate" on the faceplate. Some Early Model 200 Sustainors and all Late Model 200 Double IC Sustainors were scripted with "Smart Gate" on the faceplate. There is no correlation between this script change and the Double IC revision. So there are Sustainors scripted with "Smart Gate" that are Single IC units and there are Sustainors scripted with "Smart Gate" that are Double IC "Lead Leveler®" units. The only way for sure is to have a qualified technician open the unit for inspection.

Stage Use

On the Third Stage World Tour Scholz used a pair of newly revised Model 200 Sustainors. It is not known but assumed Pihl had at least one Model 200 and 3 or 4 "Blue Face" (Models 100 - 100A). All Tours post Third Stage have Scholz using a pair of REV 20s (during the Walk ON Tour Scholz had a 3rd unknown Sustainor in one Lead Head) and Pihl using one (1) REV 20 and three (3) "Blue Face" units.

Scholz and Pihl both use the Tom Scholz PGE2 Programmable Stereo Equalizer to control the tone and distortion levels of their Sustainors. Tone levels and particularly the output level from the Left Channel of the PGE2, which is in the Pre-Distortion Loop of each Sustainor, dictates how much distortion their Sustainors generate.


Prototype Model 100 Sustainor ( unknown )
Real early serial numbers and Prototype Model 100 Sustainors should be desirable to some serious Rockman collectors for there historical significance.

Model 100 Sustainor ( approximately 11,000 units )
With 11,000 units produced this Sustainor not even close to being rare. In fact the Model 100 Sustainor is the most common and also the least desirable Sustainor module SR&D made. With so many improved Sustainors readily available demand is low.

Model 100A Sustainor ( approximately 3,000 units )
With only five (5) to Six (6) months of production and about 3,000 units the Model 100A Sustainor is uncommon but not rare. Also not desirable because it was not much of an improvement over the Model 100. More collectable than the Model 100.

Prototype Model 200 Sustainors ( approximately 6 units )
Only 6 known to exist. Unique looking units. Part of Rockman history.

Model 200 Sustainor ( approximately 5,700 units )
Fairly common, with about 5,700 units. But a vast improvement over the Model 100 and 100A Sustainors.

Model 200 Doulble IC "Lead Leveler®" Sustainor ( approximately 1,700 units )
This is the best production Sustainor that SR&D made. Also the closest production Sustainor to the REV 19 and REV 20 Sustainors. About 1,700 units made from about mid June 1989 on. Produces a higher sonic quality and superior playablility. "Lead Leveler®" Sustainors would be the last Sustainors that SR&D produced. Units dated in 1992 command an increase in price. Units dated 1993 and 1994 ( if there are any ) with serial numbers about 21,000 and higher, would command a significant increase in price.

Non-Production REV 19 and REV 20 Sustainors ( unknown )
Extremely rare and extremely desirable. Scholz's personal units. Top collector value, given its direct relationship to Scholz. Only a few handfull made. The best Sustainor SR&D made. Exceptional for lead playing. Thirteen (13) known to exist. A true piece of Rockman history.


Sustainor 4 Channel Modification

Click here for the Sustainor Production Table

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Last updated October 6, 2003