A few words on the New Model 24
It's three units in one package: a tube DAC, a solid state DAC, and a tube Line Amp.(and a headphone amp)
You may evaluate the sound of the SS DAC by feeding its output(the Upper Analog out terminals on the rear panel, see picture) back into M24's Line In, either directly with a good (short)RCA interconnect, or better still, through a coupling transformer (more on this later)
Then you can instantly compare the difference of the SS DAC and the Tube DAC by pushing the button next to the volume control.
The SS version is designed to yield a slightly lower level. It can of course be used with other Line Amps.