Long IC Cable Run



Hi, I'm in the process of sorting out a new room in a new house. The configuration I'm shooting for requires running 16 feet of cable from my preamp to amp, and I'm wondering if an unbalanced RCA type configuration will be ok considering the long length? Otherwise, can my components be modified and made balanced (they are all unbalanced)? My system consists of a Rogue 99 Magnum preamp, Threshold S300 amp, and Arcam cd36 player. My speaker cables are Synergistic Designer Reference, power cables are VH Audio flavor 4, and no interconnects yet . . . Thanks.
128x128bdalessio
There are two main considerations:

1)The cable should be well shielded, to minimize noise pickup. It's hard to be more specific than that, because success or failure would depend on how large and how close the nearby sources of electrical noise are.

2)The capacitance of the cable should be low, so that it does not roll off the highs in combination with the output impedance of the preamp. Determine the capacitance per foot of the cable (you may have to ask the manufacturer), then multiply by 16 to get the total capacitance, then calculate the capacitive reactance (impedance) at 20 kHz based on the formula 1/(2PiFC), where Pi is 3.14, F is 20,000 Hz, and C is the total capacitance in farads. C will probably be on the order of 500 to 1000 picofarads (a picofarad is a trillionth of a farad). If the result of that formula is significantly larger than the preamp's specified output impedance, you'll be ok.

Regards,
-- Al
Even XLR cables this long can degrade the sound- RCA much worse. Check with Rogue that the output of your preamp can drive it.

Your best bet is to rethink positioning the system to accomodate <1.5M cables
IC's of that length are fine, but please do pay attention to the post by Al regarding cable shielding and capacitance. You need a cable that is designed to handle that length of run. Please note that if you have an sources of nearby electromagnetic noise (AC wiring for example), a coaxial style interconnect will not be a good choice. You need a cable with ability to reject electromagnetic and electrostatic noise.
16 feet is not that long and any good quality shielded cable will do the job. If your components are truly balanced then balanced cables are the way to go though I doubt you will here any difference between single-ended and balanced, with single-ended components, at 16 feet.
The ideal solution for this application is the Photon AMP cable from Harmonic Technology (formerly Cyberlight). This presents a load to the pre of about 12" of interconnect and since the audio signal is converted to light and back to audio, there is ZERO chance of any ground noise or hum. Not a cheap solution to be sure, but an excellent one. Check with Mark at Rogue - they showed with HT Cyberlight cables at CES a couple of years back. Good Luck!
>>11-20-08: Tweak1
Even XLR cables this long can degrade the sound<<

Totally and unequivocally not true.

Balanced cables were designed for much longer runs than 16'.
Tweak1 is wrong. That long cables are bad and long wires are good is the position of Pierre at Mapleshade and some others. That long interconnects are better than long speaker wires is maintained by Martin Colloms and others. I have tried both and find the latter to be correct. But as the others say use care in selecting the cable you use. I use SilverBlue from Audio Synthesis. I have no idea of its current cost. And be sure that the preamp can drive the cable. It is best to check with the manufactures. I use unbalanced over 4M and it works very well.