Rhodes, from a technical standpoint the Sutherland PhonoBlock appears to be suitable for use in your system. Regarding output impedance specifically, John Atkinson’s measurements indicate "200 ohms across the audioband," which is fine for use in conjunction with a 20K load impedance.
As Jond alluded to, though, the sonic quality it is capable of providing figures to be limited by the Benchmark, and I suspect also by your power amplifiers.
Good luck, however you decide to proceed. Regards,
-- Al
As Jond alluded to, though, the sonic quality it is capable of providing figures to be limited by the Benchmark, and I suspect also by your power amplifiers.
Good luck, however you decide to proceed. Regards,
-- Al