The Roland S-550 was a professional 16-bit rackmount digital sampler introduced by Roland Corporation in 1987. It was designed as the rack version of the Roland S-50 keyboard sampler but offered a number of expanded features that made it a more advanced and flexible option for studio and live applications. The S-550 was aimed at professional musicians, producers, and sound designers seeking high-fidelity sampling and extensive editing capabilities in a compact rackmount form factor.
The Roland S-550 features 16-voice polyphony and utilises 16-bit linear sampling, supporting two selectable sampling rates: 30kHz for higher quality and 15kHz for extended sample time. The internal memory is 1.5MB standard, which can be expanded to 2.0MB with the optional Roland OP-5504 memory expansion board. With the full 2.0MB memory installed, the Roland S-550 offers up to 28.8 seconds of sampling time at 15kHz or 14.4 seconds at 30kHz. The S-550’s memory is non-volatile when powered, but samples need to be saved to disk to prevent loss when turned off.
One of the key advancements of the Roland S-550 over the earlier Roland S-50 is the inclusion of eight individual audio outputs in addition to the stereo mix output, allowing for complex routing of multiple samples to different channels on a mixing console. This made it ideal for multi-timbral setups where separate processing and panning of individual sounds were required.
The Roland S-550 uses a built-in 3.5-inch Quick Disk drive for loading and saving sample data. While slower and less capacious than hard drives or other storage formats of the era, Quick Disks were widely used by Roland instruments at the time and offered a cost-effective solution for sample storage. The Roland S-550 is compatible with Roland’s extensive sound library, including sounds designed for the S-50, S-330, and other samplers in the same series.
A standout feature of the Roland S-550 is its video output, which allows the user to connect an external RGB monitor. When combined with the optional RC-100 remote controller and mouse, the S-550 provides a graphical user interface (GUI) for sample editing. This system enabled visual waveform editing, graphical envelopes, and parameter adjustments that were highly advanced for its time. The graphical interface was considered a significant innovation in usability, making complex editing tasks more intuitive compared to other samplers of the era, which relied on small LCD displays and menu-diving.
The Roland S-550 offers comprehensive editing features, including key mapping, auto-looping, velocity switching, and time-slicing. Its sample manipulation tools include digital filters, envelopes, and LFO modulation. Samples could be assigned across the keyboard in multi-timbral setups, with flexible zoning and key splits, allowing for sophisticated layered or split performances. The sampler supported MIDI control, offering MIDI In, Out, and Thru connections, making it easy to integrate with other MIDI-based equipment.
Physically, the Roland S-550 was housed in a standard 3U rackmount chassis. Its dimensions are 483mm wide, 410mm deep, and 132mm high, and it weighs approximately 9.5kg. It features a clear front panel layout with controls for basic operation and a display screen that shows operational information when not connected to an external monitor.
The Roland S-550 found favour among professional users for its sound quality, flexible output configuration, and innovative graphical editing system. It was widely used in studio production and live performance throughout the late 1980s and early 1990s. While it never achieved the same widespread acclaim as the Akai S1000 series, the S-550 was nonetheless a respected tool among those who appreciated its unique workflow and integration within the Roland ecosystem.
Although considered limited by modern standards due to its small memory capacity and reliance on Quick Disks, the Roland S-550 remains a sought-after sampler for enthusiasts of vintage digital samplers. Its distinctive sound, shaped in part by its digital-to-analogue converters and filtering options, continues to appeal to musicians seeking the sonic character of late-1980s digital sampling technology.
