Ah, that's easy. They're connected to my Constellation Inspiration integrated amp's speaker terminals. The S400IIs also have nice binding posts; Mads really went through and used very-high quality parts throughout this speaker's components.
I set the volume on the Inspiration to Unity Gain, and then adjust the actual output volume using the P1's LEEDH volume control, which I find to be superior sonically to the Inspiration. So effectively, the Inspiration integrated simply functions as the power amplifier. The amplifier section of the Inspiration integrated amp
is the "standalone" Constellation Inspiration stereo power amp, just with half the number of output devices, so it outputs 100 Wpc RMS instead of 200 Wpc. Other than that, they are identical.
So...it's
really good power amp, too.
With my 'Beths, which are nominally 6 ohm, sometimes I also the P1 as the preamp for use with my little Amp Camps amps I built up. Running as bridged monos, they put out 15 Wpc pure Class-A power, so they're more than enough for the levels I listen at (nominally 68-74 dB). And, as they're designed by Nelson Pass, they sound...
really good. I also upgraded the parts specification doing the build, with all Vishay metal-film resistors, and larger value audio-grade caps in the power supply.
The little ACAs sound...GREAT. That's Nelson for ya...
-Stephen aka PC