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Luma-1 Drum Machine - Linn LM-1 - $3,250 (hercules, pinole, san pablo, el sob)
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Bubinga side panels
Serial #19
Includes heavy duty road case
Luma-1 is an authentic recreation of the iconic LM-1, originally designed by Roger Linn in 1979 and now brought back by Joe Britt (check the creation story at Roger’s site). Fully recreating the original design of the LM-1, it utilizes the same audio path with the original vintage DACs and filters, runs the original LM-1 software, and adds a secondary modern processor for adding highly desirable features like loadable sounds, USB connectivity(USB MIDI Client and Host), MIDI and more.
What determined the cost?
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Similar to the original LM-1, Luma-1 is a very complex machine. It has a dual CPU architecture (Z80 + ARM) and makes no compromises with the audio path. Luma-1 uses the original nine individual DAC chips, and the original “loose” clock generation scheme. The DACs are no longer produced, and were obtained from surplus stock suppliers.
The digital sections are identical, but Luma-1 uses small SMD (Surface Mount Device) components to save space. A modular design was implemented, where each voice is on its own card for serviceability and future expansion or modifiability.
The power supply is the exact same model used in the LM-1, and amazingly it is still made in the USA! It is a linear power supply, which is heavier and more expensive, but doesn’t have any “switching noise” concerns of more modern supplies.
Finally, the enclosure is modeled after the original LM-1, with the same width and height to preserve the front panel user interface. Thanks to the smaller SMD components, the overall length of the enclosure is 4” shorter than the LM-1. The enclosure is made of 3 custom steel sections, each powder coated. The control panel and rear are illustrated with custom silkscreen printing. The side panels are wood, like the original LM-1, but with a variety of wood types available. Luma-1 weighs 25 lbs (a little over 11 kg).
Is the circuit exactly the same? What's different?
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Luma-1 uses a Z-80 just like the original LM-1, and runs the Rev 3 LM-1 firmware.
It has the same loose sample rate and tempo clock generation, 9x (one per voice) 8-bit µ-law DACs, OpAmps, and AS3320 (or CEM3320) filters on the Conga/Tom and Bass voices. Unlike the original, the filter cutoff controls are externally accessible.
In other words, the entire audio signal path is identical to the LM-1.
On the digital side, the samples are not stored in EPROMs, but rather individual per-voice RAM chips. Drum samples are loaded into those RAM chips either from an internal SD Card or by downloading via SysEx. That allows for hot-swappable sample storage, whether it's the original bit patterns of the LM-1 voice EPROMs, other sample-based drum machines (such as the DMX or DrumTraks), or totally new sounds. Samples can be 2KB, 4KB, 8KB, or 32KB in size, allowing a wide variety of vintage and new sounds to be loaded. (Note: due to the way the Conga/Tom voices work, those samples can be 2KB, 4KB, 8KB, or 16KB.)
To facilitate these features and more, a new ARM CPU works in tandem with the original Z80, which has the bonus effect of allowing easy implementation of MIDI and USB.
However, two compromises were made:
The original cassette tape memory system has been omitted, since all patterns can be saved to and loaded from SD Card.
The original “Tape Sync” that let the LM-1 chase a sync tone laid down on audio tape has been replaced with synchronization via MIDI Start/Stop/Clock.
What is Roger’s involvement and why isn’t his name on it?, is Roger permitting this?
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From Roger: “I think it’s very cool that my friends Joe, Andrei and Devin are breathing new life into the LM-1, recreating the original circuit, sound and timing while adding some useful modern features. These guys are in it purely for the passion and are far better engineers than I am, so I’m honored that they’re taking on this project. It’s entirely their project, but I’m staying in touch with them and giving some help along the way."