Because the official sources are gone, the community has stepped in to archive the software. These sources are not officially sanctioned by Roland, and you should be aware of the legal gray area. However, they are currently the most functional way to obtain the plugin.
If finding a functional download link and configuring a bit-bridge proves too tedious, several modern alternatives offer a similar workflow and sound palette without the compatibility headaches: edirol super quartet vst 152 download link
A widely used, affordable utility for Windows that converts 32-bit VSTs into a format 64-bit DAWs can read. Because the official sources are gone, the community
Because the Super Quartet is a discontinued product, it is no longer sold or officially supported by Roland. Consequently, you won't find a direct, official retail page to purchase it. Instead, consider these approaches and precautions: If finding a functional download link and configuring