Harry Axten aka HKA Design should be well konwn to you now, with his array of modifications for classic hardware units - bringint them up to date with a wealth of features. Here is his 707 modification, giving the machine 8 banks of sounds you can select, including the stock sounds from both the TR-707 and TR-727. The 8 banks included are :
Here's what he has to day:
Realised I haven't done a video showing the current version of the TR-707 ROM Expansion modification - it now allows switching kits at any time while the machine is running, done by holding down the enter button and pressing one of the first 8 step buttons. This TR-707 also has the optional cymbals board installed, which allows the last two sounds (crash & ride cymbal) to change as well. More information here -
Get all the info here: https://hkadesign.org.uk/tr707expansion.html
About the author [midierror]: midierror makes nifty Max For Live devices, innovative music hardware, award winning sample packs and hosts a podcast speaking to people in the music world.
Developments for Korg's instrument have been slow but promising.