This is the latest V4.10 OS for your SD-1 whether it is the 21-voice or 32-voice model, made with a brand new & never before used chip, & shipped quickly & safely, packaged in anti static materials. The ROM comes with a 1 year warranty. Adding this OS to a 21 voice model doesn't give you the extra voices, but it does let you load in 32 voice-mode patches as well as the ability to load in the 4.10 Sequencer OS.

2 DAY SHIPPING IS INCLUDED IN THE LISTING PRICE! If you make an offer below the listing price it will not ship with 2 day shipping. Feel free to put in an offer if you are not in a rush.

We also offer the SQX-70 upgrade for the SD-1, and stock many other ROM upgrades, if you can't find something you need, send us a message!