Alesis HR-16 modding

Alesis HR-16

This article is not meant to be a detailed manual for modding your HR-16, there are numerous pages on the web already explaining what can be done. This is just a little picturebook.

The ups of the Alesis HR-16:

  • great design and easy to understand
  • quite punchy sounds
  • 12 bit with special and very clever ‘compression’ to improve resolution and sn-ratio
  • Sounds can be pitched indiviually
  • Velocity on Drumpads and Midi

Bad contacts

Unfortunately the contacts of drumpads and rubber buttons are often worn out. Users start to use force making things even worse. The hardware of the HR-16 hardly can bear this. There are special coatings getting worn out contact to conduct like new. I made quite good experience with CAIKOTE44.



Most important mod: adjustable global pitch. It’s accomplished with an adjustable Highspeed-Oszillator (LTC-1799) supplying the system clock for the sound generation unit. The rest of the drumcomputers OS is not affected.


Sawing openings

The 48 samples of the HR-16 are stored on 2 EPROMs. By replacing them you can feed new samples into the HR-16. Replacing EPROMs is much faster if the sockets are on the outside. The 3rd socket is for the firmware EPROM, it contains the start addresses of the samples. To be able using the HR16-B’s soundchips you also need to replace the firmware ship.



The sockets on the main PCB fomerly holding the EPROMS are not populated with pinheaders to which the multipin cables are soldered. The other end of the cables are leading to the sockets on the top of the machine.


Cable chaos

Although it looks frightening it works thorougly. The Hardcore-Circuitbender love to interchange different address- and data-cables to get extreme digital sound glitches – not really my thing.



Finally a music video where the modded HR-16 was used: