Pro Audio

Turn your TR-707/727 into a range of classic drum machines with ROM expansion

HKA Designs are now offering a ROM expansion for the Roland TR-707 and TR-727, adding iconic sounds from a variety of vintage drum machines.

UK-based design engineer Harry Axten has developed a new ROM expansion kit for the Roland TR-707 and TR-727.

The HKA Designs kit now makes this vintage drum machine more versatile than ever.

TR HKA Design ROM Expansion

The kit gives your drum machine 8 banks of sounds to select from, including both the TR-707 and TR-727. This allows people who don’t own both machines to turn one into the other, or into a TR-808, TR-909, LinnDrum, Linn LM-1, Oberheim DMX, and TR-707 + TR-727 mix. All of these sounds can be heard on many albums, the machines becoming iconic in their own right.

HKA achieve this without changing the TR-707 interface. The bank switching is done by holding down one of the first 8 step keys while turning the machine on. The settings are remembered for the next time you power it on, plus the whole installation is easily reversible.

All sounds within the banks are switched except for the last two sounds (crash + ride/quijada + chime), which remain the same across all banks. The entire library is stored as 8-bit linear PCM at either 12.5kHz or 25kHz sample rates. The kit just requires some beginner soldering and wire stripping skills to install.

The TR-707 expansion kit retails for £60 with free shipping included, although sold out at the time of writing. To keep up to date visit the HKA Designs website.