The cathode current is only 0.15 mA, but the preamplifier delivers a 3.5x gain. There is more detail on his website. It would be interesting to subject this circuit to a full audio analysis and ...

Each preamplifier has 16 inputs, including 9 analog and 7 digital connections. From analog to digital, the C55 and C2800can accommodate a wide range of audio sources, including turntables via ...