Linn LM-1 HiHat

YouTube via rolandsh1000
"This video documents the sample output of the Linn LM-1 as compared to the Oberheim DXa. The Linn LM-1 has been well noted for its characteristic 'groove' which is felt to be unique among EPROM-based digital drum machines.

Many have suggested that the slightly imperfect timing of the Linn LM-1 is responsible for the feel and I think that's at least partially true. But the LM-1 also has a unique way of creating its HiHat sound, which I wanted to show.

Most EPROM-based drum machines (re)trigger their Hat sample from the beginning of the sound in the stored EPROM. This gives a consistent but static delivery of the sound sample. The LM-1, however, has its EPROM clocked continuously, which means the sample is always being looped. To trigger the Hat sound, the LM-1 merely applies a volume envelope to the DAC. This means that the LM-1's HiHat output is a little different each time it is triggered. My guess is that Roger Linn did this either because memory was very expensive in the late 1970's or he's brilliant in realizing that each strike of a real cymbal is unlikely to be exactly the same ... or both!

The video shows the EXT CLOCK OUT of the LM-1 triggering the DXa via the Oberheim's EXT CLOCK IN (not MIDI). The top trace is the Hat sample of the Oberheim DXa and the bottom trace is the Hat sample output of the LM-1. You can clearly see the difference in the sampled waveform between the two machines.

I tried hacking my DXa to do this and it sounded kind of cool, but you really have to have the right HiHat sample for it."