Para standard corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:dirkmueller:Factory/standard/home:dirkmueller:Factory.repo
zypper refresh
zypper install amsynth
Para p corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:dirkmueller:Factory/p/home:dirkmueller:Factory.repo
zypper refresh
zypper install amsynth
Para a corra o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:dirkmueller:Factory/a/home:dirkmueller:Factory.repo
zypper refresh
zypper install amsynth