Eldartford, probably should have said
600 ohms or less
As for the Krell, here are the specifications for its RCA outputs. No balanced outputs on this model, but who cares with that low an impedance?
Sidebar 1: Specifications
Description: Solid-state, remote-controlled, stereo integrated amplifier with 5 line-level inputs
1 balanced, 3 single-ended
1 single-ended tape loop
1 set of single-ended preamplifier outputs.
Power output: 200Wpc into 8 ohms (23dBW)
*Output impedance: 0.17 ohm*
Even inexpensive cables, such as sold by The BlueJeans Cable Company ($83.00 for 50 Ft. RCA) is only 17 picofarads of capacitance per foot.
The point is, it's what this gentleman needs to keep peace in his home. I have a pair of 60 foot BlueJeans RCA cables in my HT system and it's OK for that use.