A more limited spectrum of tests was run on the Sumo than is usually the case because its floating ground requirement was incompatible with some of our test equipment. As can be seen from fig.1, the Andromeda II has only a very slight rolloff at the frequency extremes. There was a slight mismatch in gain between the two channels: an insignificant (in practice) 0.3dB. The 1kHz input impedance measured 42k ohms. The output impedance was below 0.06 ohms up to 1kHz, rising gradually to a maximum of 0.09 at 20kHz.
Fig.1 Sumo Andromeda II,…