Linn LM-1 LM1 Drum Machine

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"Linn LM-1 drum machine, serial # 365. These are relatively rare, as only approximately 500+ were ever built. This model was the first commercially-available EPROM-based digital drum machine with 8-bit sampled sounds.

While this is a digital drum machine that uses 8-bit EPROM based samples run through companding DACs, nothing really sounds like the LM-1. The snare and bass have a very solid fat sound, and the hi-hat is very unique: the hat sample is constantly running, and the difference between the open and closed sounds is merely a long or short analog envelope applied to the sample output, respectively. So even with metronomic triggering, the hi-hat has some ‘feel’ since the envelope is applied at varying points in the playing of the sample. I made this video to demonstrate this effect:


YouTube via rolandsh1000

Finally, there’s actually some analog processing inside to smooth out some of the ‘rounder’ sounds: the toms and the bass get processed by a classic CEM 3320 VCF chip.

Here are the basics:
- 9 voices:
- Bass (2 volume levels)
- Snare (2 volume levels)
- Hi-hat (2 volume levels and an open hat)
- Toms (2 tuning levels)
- Congas (2 tuning levels)
- Cowbell (1 volume level)
- Tambourine (2 volume levels)
- Cabasa (2 volume levels)
- Claps (1 volume level).
- Individual ¼” outs for each drum sound
- Left/right mix ¼” out for the all voices (though both outs are same mono mix)

- Start/stop foot switch input ¼” jack
- Internal clock output ¼” jack (48ppq in HiRes setting)
- Tape sync to/from ¼” jacks for sync’ing with recorded tracks
- Tape storage to/from ¼” jacks for drum pattern data storage
- External Clock In ¼” jack (48 ppq) –

o Note that this is a modification that I’ve added back into this LM-1. The circuitry is all still there, but Linn left it out of later versions, so many later LM-1’s don’t have this feature. This makes the LM-1 syncable with other equipment.

So what’s different about this particular LM-1? Well, one of the terrific features of the Linn LM-1 was the external tunability of the voices, each with its own knob. However, this tunability wasn’t apparently conceived as a performance feature, but rather as set-the-tuning-per-song, so the tuning pots were located on the back. Not only were they very difficult to reach from the front, it was difficult to guess at which voice you were tuning.

So this LM-1 has tuning pots on the front panel, right above the label of the drum, so there’s no confusion about which drum tuning you’re adjusting (see the pics). The last “tuning” pot, which sits above the Click, is actually the open Hi-Hat decay adjustment. I used Kilo knobs that match the very nice original Alco knobs that are used for Tempo and Volume. This modification makes the LM-1 a lot more fun to play in real-time.

This tuning mod is possible, because the original 3-position panning switches were OFF in the center position. So not having the switches connected means all voices are tuned to the center of the left-right pan. But the LM-1 has individual outs, so the need to use the native stereo mix from the LM-1 seems almost unnecessary today. If you want a mono mix, you can now get it at the Left or Right output at the rear of the machine. And serious LM-1 users will choose to bring individual drums through their individual outs to an external mixer, for compression, EQ, etc.

I put hole plugs over the now vacant holes in the back of the chassis where the old tuning pots used to be, as well as replaced the old chrome hole plugs that were in some of the abandoned holes in the back. So now the rear panel has a clean look (see the pics).

Here’s a video demo of this LM-1:"

Linn LM-1 with Front Panel Tuning