Amarra and JRiver are two of the better alternatives if you're determined to run from your iMac.
If not, IME you'll get far more musical joy and far less UX frustration moving from Mac/Audirvana to a Linux Core(Roon Nucleus, Intel NUC or in my case Small Green Computer SonicTransporter and Run Roon. Use any tablet, phone, and/or your iMac as remote controls. But that is a whole different conversation. Cheers,
Spencer
If not, IME you'll get far more musical joy and far less UX frustration moving from Mac/Audirvana to a Linux Core(Roon Nucleus, Intel NUC or in my case Small Green Computer SonicTransporter and Run Roon. Use any tablet, phone, and/or your iMac as remote controls. But that is a whole different conversation. Cheers,
Spencer