Review | Sound On Sound, Jan 1987
Yamaha's DX7 may well be a classic keyboard but its MIDI implementation and small onboard memory are starting to look decidedly limited compared to newer generation keyboards. What's needed is an upgrade, and the add-on E! board from America's Grey Matter Response is certainly that! Martin Russ enthuses over its features.
Review | Music Technology, Sep 1987
for the DX7, Version 2.0
The debate over whether to upgrade to a DX7II takes on a new dimension with the possibilities that this expansion board brings to the original. Jim Burgess is impressed.
Review | Music Technology, May 1988
For the DX7II
Grey Matter Response's E! expansion for the DX7 virtually gave it the power of the DX7II; E! for the DX7II represents another quantum leap in DX capability. Chris Many checks it out.