Sources Harmony Central
Citation : Owners of Waldorf's Microwave II or XT will soon be able to triple the number of available voices to 30 with a new expansion option. This option offers three times the internal DSP power of the synthesizer, and earlier models will also benefit with the additional effects that are only found on later Microwave II and XT models.
The upgrade procedure varies depending on the serial number of the unit, and in some cases, the main board will be completely replaced in order to complete the upgrade. The price of the upgrade is the same in either case however.
To accept an upgrade order, owners will have to provide the machine type (Microwave II or XT) and the serial number. The upgrade must be performed by official Waldorf distributors or service centers. The upgrade should be ready in the first quarter of '99.