Additionally, I believe (though I am not 100% sure) that the ARC is a full tubed preamp and does not have coupling capacitors in use for its output. Krell does recommend that if you use a full tubed preamp that you activate the coupling capacitors in your Krell amp for protection for DC signals. Of course, you are now adding these caps into the signal (the only caps in the Krell signal) so this may impact the sound as well of the amplifier.
Just out of curiosity, any krell amp owners running all tubed pre-amps (without coupling capacitors to prevent the passing of possible DC - ie. from the tubes) into their Krell amps? Have you activated the coupling capacitors in your krell amps? If not, any problems? What preamps are you running?
Just out of curiosity, any krell amp owners running all tubed pre-amps (without coupling capacitors to prevent the passing of possible DC - ie. from the tubes) into their Krell amps? Have you activated the coupling capacitors in your krell amps? If not, any problems? What preamps are you running?