PHONO PREAMP

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

Based on your system description thread it appears that the outputs of the phono stage would be driving the analog inputs of a Benchmark DAC2 HGC. The analog inputs of the Benchmark (which are only provided as unbalanced RCAs) have a specified impedance of only 20K, which will be marginal (or worse) for use with many tube-based phono stages, including some of those that have been suggested.

For example, the Lamm LP2.1 has a specified nominal output impedance of "typically 2.3K," which I suspect is significantly higher at deep bass frequencies, and even 2.3K does not meet the rule of thumb guideline of a 10x minimum ratio. Also, the ARC Ref Phono 2SE has a recommended load of "50K-100K ohms and 100pF (10K ohms minimum and 2000pF maximum)," which would seem to imply that a 20K load is not ideal.

Regards,
-- Al