I read the latest Hifiman HE-560 review over at Headfonia and found the following to be very interesting: I've read somewhere that with certain tubes the Crack output impedance can get as low as 70 ohm. And the HE-560 is 50 +/- 8 ohm. Not a terribly large difference. Perhaps it's something to try?
10/8/14 at 4:13am