ROM expansion turns Roland TR-707 into an 808, LinnDrum and more

It gives you eight sound banks of iconic drum machine sounds.

Roland 727 HKA Design PCB

Image: HKA Design

For those old school enough to still work with a Roland TR-707 or 727, have we got news for you. HKA Design has announced a ROM expansion that lets you add on the sounds of the iconic TR-808, TR-909, LinnDrum, Linn LM-1 and Oberheim DMX.

The expansion gives you a total of eight sound banks, including the stock sounds of both the TR-707 and TR-727. Switching between banks is performed by holding down one of the first 8 step keys while turning the machine on.

Aside from the new sounds, HKA Design said that the modified TR-707 or 727 should behave just like a stock unit – with no loss in function. As such, it should also be compatible with other modifications or circuit bends you may have previously added. Check out the mod in action below.

The kit does require a fair amount of soldering, but comes with instructions on how to install the expansion without wrecking your precious vintage unit. The full kit consists of a pre assembled PCB, a ribbon cable and a DIP socket.

HKA Design also shared a detailed write-up on his process of porting the sounds from the TR-808, TR-909 LinnDrum, LM-1 and DMX over to the 707 and 727. You can read here.

The expansion kit is available at $60 through

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