Parasound A21+ amplifier and Topping Pre90 preamplifier

This is one combo where the messed-up gain or impedance or whatever of the pre90 did not conflict with the amp. The other good case was with the Benchmark AHB2. With these 2 amps the pre90 sounded exactly like the great Benchmark LA4 preamp. With other amps the pre90 drove me nuts with volume issues (too loud).

Topping Pre90 line preamplifier | Stereophile.com

I have the A23+ with Pre 90, it is fabulous. Very high performance preamp. Especially with xlr.