The Sample Journal

Comparing Two LM1 Drum Machines

Posted on January 12, 2024 by Samples From Mars

The LM1 (often mistaken for the Linndrum) is an incredibly groovy, classic and rare drum machine from the 80s, most notably popularized by Prince. After waiting years to find (and afford) this holy grail of 80s drum machines, we finally acquired one in 2018 (see below, left) and sampled it extensively.

But just a year later, we acquired another unit! 🤷🏻‍♂️ This mysterious looking LM1 (see above, right) featured a curiously gray faceplate, softer, more pillowy pads, and sounded somehow warmer and lazier! Oddly enough, the research we've done has provided no explanation for this.

Since we never added the samples from this gray machine to the LM1 From Mars pack, we figured grabbing a few kits from both units would be the perfect way to explore and compare the subtle differences between these amazing machines. you can download the samples for free here:

LM1 COMPARISON - SAMPLE JOURNAL FROM MARS

$0.00

6 kits recorded cleanly to compare the differences between the LM1 Rev 2 and LM1 Rev 3 drum machines 🥁🥁

Matching tuning and filter settings, we captured one hits and two beats. You can download the new samples above (they're also included in the everything bundle). You'll get 3 kits from each machine, and 3 Ableton racks to switch between units 🕺🏻

Can you hear the differences, or do they sound identical to you? While the video only shows very subtle differences, the one-shots will prove otherwise upon more critical listening (try headphones).

The orange LM1 has a harder, punchier and faster sound (almost like a 707), while the mysterious, gray unit is warmer and lazier. Something about the bass drum filters sound completely different between the two, and the cabasa is either a different sample entirely, has more distortion, pre-attack, or all of the above. The orange unit also has a modded snare sample with less pre-attack, so that it arrives a bit earlier when sequenced. All of these differences give each machine their own distinct sound, feel and pocket.

Design History

The Linn LM1 had three different released versions (known as revisions, or "Rev" for short). Roger Linn's first prototype was housed in a cardboard box (but this doesn't count as a revision lol).

The original Rev.1 is recognizable by its lack of LEDs for auto-correct and shuffle. It had engraved buttons and the drum buttons had symbols for each drum that they represented. Internally, it had single eproms for kick, toms and congas. There was no filter on these voices.

LM1 Rev.1 (1980)

The Rev.2 had two rows of LEDs added for auto-correct and shuffle. It had 24db CEM filters added for the kick, toms and congas. To cut costs, the engraved buttons were replaced with unlabeled buttons and names were printed on the sides. However, there are some rare Rev. 2 LM1s with both engraved buttons and shuffle and auto-correct LEDs. Interesting...🤔

LM1 Rev. 2 (1981)

The Rev.3 retained the sweet CEM filters but employed more cost-cutting measures like button size changes, and some switches/functions taken out. For example, the record/safe switch that helped with the accidental erasing of your programmed data was removed. The low level stereo outputs were removed. Later Rev.3's had the raised buttons replaced with flatter, flush to the surface buttons. Interesting again...😏

LM1 Rev. 3

Based on the information above, it can be deduced that our original black LM1 is a Rev.3 and our mystery LM1 is an early Rev.2! 🎉

The Sound

While we can deduce models based on appearance, internal electronics and sound are harder to nail down. LM1s have been known to be messed with and modified (included ours). Our Rev.3 had the tuning knobs relocated from the back to the front panel (beware of this mod as it can - and did, on ours - add a whine to the Mix Out). It also had the snare sample modded for less pre-attack.

Based on the two machines we have in our possession, how do they differ in sound?

The Rev.2 has an overall warmer and softer color and timbre. The Rev.3 sounds more aggressive and punchy. Some drum voices on the two machines are very hard to tell apart, while others like the kick and cabasa are leagues apart.

The Filters

On most LM1s, there are filters on the kick, toms and congas that can be tweaked by opening up the machine and adjusting trimmers. We tried to match the filter settings, but they still didn't sound the same. There’s something with the filter or filter envelope that sounds warmer on the Rev.2. The resistance could be different, or possibly the gain staging is opening the dynamic filter more or less. We're not sure what's going on! We contacted an original designer of the LM1 and they said these two LM1s *should* sound the same!

Opening up each machine, we tried to visually confirm as much as we could. Both LM1s have the same filter chip, a CEM 3320 VCF. This is a classic chip used in other drum machines and synths like Sequential Pro One, Oberheim OB-Xa and Elka Synthex.

LM1 Rev.3 Filter & Trim Pot:

LM1 Rev.2 Filter & Trim Pot:

Maybe some eagle eyed engineers out there will spot some differences in the circuits?

The Tuning

There are also tuning range discrepancies between these two machines. The Rev.2 congas and toms can go higher than Rev.3 but Rev.3 congas and toms can go lower. The cabasa sounds completely different - we think it's a different sample. The Rev.2's rimshot is labelled as 'clave' on the pad, but we couldn't find any information on why. Perhaps it was an option to swap the rim sample for a clave for some time.

The grooves on the machines differ too! The groove feels tighter on the Rev.3. This is due to the more aggressive sounding kick and the quicker onset of the snare drum. Conversely, the warmer kick with the later occurring snare sample give the Rev.2 a looser sounding groove.

When listening to classic records with an LM1, it's fun to examine and attempt to guess what version and variation of LM1 they were using. 🥁

The Samples

The differences in sound are best explored through the one-hits. This is not an extensive multi-sampling, but (3) 18x hit kits from each LM1, including all of the drum voices. We built these into three Ableton drum racks, with a macro knob that switches between the two machines - a very effective way to compare them. We also included the stems from the video above for fun :)

We're curious which LM1 you prefer. Can you hear any other major differences? Is one better suited for a certain style? What do they sound like mixed together?