MOTM

MOTM is a modular synthesizer format originally produced by the American company Synthesis Technology. It was introduced by engineer Paul Schreiber in 1998. The modules available from MOTM form a complete system featuring oscillators, envelopes, VCAs, utility modules such as mixers and multiples, and numerous filter options based on classic circuits from Moog, Yamaha, Korg, and others.

The MOTM format established a standard for synthesizer modules, with a height of $8 3⁄4$" and a single module width of $1 3⁄4$" for a 5:1 height:width ratio. $1 3⁄4$" is the standard height of rackmount audio equipment, a unit which is referred to as a "rack unit" (or 1U). At a height of $8 3⁄4$", MOTM modules are 5U (five rack units) high and multiples of 1U wide. MOTM modules and other modules compatible with the MOTM format are commonly referred to as "5U" modules.

MOTM modules share some details with the Synthesizers.com ("Dotcom" or ".com") format, such as an overall height of $8 3⁄4$" (5U) and the use of $1⁄4$" jacks. However, Dotcom modules are wider ($2 1⁄8$") and use a different power connector. Although MOTM modules utilize the same typeface used on the classic Moog Modular systems, and also feature Moog-style knobs, their aesthetic is less derivative of Moog, with a more consistent grid-based layout. The front panels of MOTM modules are also made of $1⁄8$" (3.2mm) thick aircraft aluminum, whereas Dotcom modules are made from thinner material that requires a bend on the side of each module to prevent panel flexure.

MOTM modules require ±15V power, delivered via a 4-pin MTA-156 connector. Some newer MOTM designs (such as the MOTM-650 and MOTM-730) include digital circuits that require an additional +5V and a 6-pin connector. MOTM power supplies and cases use a power distribution board with multiple connectors, and short cables with female MTA-156 connectors at each end are used to connect power to the modules. Small distribution boards (available from MOTM, Bridechamber, and STG Soundlabs) can be used to add Dotcom-compatible modules to systems that use MOTM power supplies (such as the MOTM-900 and MOTM-950).

Modules in the MOTM format are available from manufacturers such as Bridechamber, Oakley, Tellun, Cyndustries, and Analog Craftsman. The Modcan B format also uses the same module dimensions and power connectors as MOTM. Modules in the Frac and Wiard 300 formats are not the same size as MOTM modules but use the same power connectors.

At one time, a group of enthusiasts known on the Synth-DIY mailing list as "Stooge Panels" offered a series of panels designed for conversion of specific Frac and Eurorack modules to MOTM format, as well as MOTM-format panels for popular DIY projects. However, this went inactive after the untimely death of Stooge Larry Hendry in 2006. MOTM panels are now available from Bridechamber or other DIY sources.

As of May 2012, Bridechamber handles all distribution of MOTM kits and assembled modules. Synthesis Technology also offers several DSP-based modules in Eurorack and Frac format, which may eventually be available in MOTM format. Eurorack modules from SynthTech include standard 12V power connectors as well as MOTM-compatible connectors.

MOTM characteristics

 * 1 volt-per-octave response for control of pitch-related parameters (i.e., VCOs and filters)
 * Positive-going voltage Gates (+1.5V threshold)
 * Positive-going voltage triggers
 * Audio levels of 10V peak-to-peak
 * VCAs respond to amplitude control voltages from 0 to +5 volts