Well Gooberdude; if anyone has any measurements as to why this is, please be sure to share them with us. After all; this is the Lab section and we do take some interest in measurements.
d.b.
Dang Dan... why do you have to harsh everyone's buzz? Gooberdude might not be a technical Poindexter, but his interest is real. I've no idea why (or if) these biased interconnects work, but some folks whose opinions I value seem to think they're the cat's meow. Supposedly, they work on the assumption that a signal that never traverses the return/shield potential has some benefits vis a vis dielectric involvement. Sounds like typical whitepaper scientifical stuff to me
Nor does it jive with what little I know of instrumentation driven shields.
That being said, for the truly enthusiastic diyer (meaning someone with more enthusiasm than common sense, like myself), if you have the proper components, you could do a very interesting experiment.
If your preamp's output is driven single rail, as is typical of many tube output preamps, or its similarly single rail output solid state like -
http://www.tnt-audio.com/clinica/preamble.htmland it blocks this dc offset with an output capacitor,
AND
Your poweramp has an input capacitor with a voltage rating sufficient to handle the pre capacitor voltage from the preamp, then,
Remove the output capacitor from your preamp, and let the poweramp's input capacitor deal with (block) this offset voltage.
This will -
1.Bias the signal leg of the interconnect so that its voltage swing will never ever cross the voltage of the return/shield, providing whatever benefits associated with dielectric grooviosity.
2. Eliminate coupling capacitors, rather than add them for the intervening biasing, as well as using the preamps inherent biasing ability, rather than add ancillary circuitry.
3. Be a virtual guarantee that if you don't power on your poweramp last, and power off it first, you will blow your poweramp and/or speakers.
4. Even if you reap tremendous subjective improvement with this Byzantine arrangement, you'll not know if it was due to the biasing or the elimination of the preamp's output cap......
If you don't fully follow and understand this, don't even consider doing this. And don't ask me for further explanation. Its function and danger should be obvious to anyone attempting it.
Dangerous and hairshirt. Who could ask for anything more?
Then again, a current Stereophile class A rated $20K solidstate amp will go into oscillation and self destruct if you power it up with no speaker load attached........
EDIT - Actually, point #4 is not true. You could make a 'definative' conclusion by doing the following. With that same single capacitor/channel connection between preamp and amp, listen (double blinded, single blind...) and evaluate. Then simply move that single capacitor to the source end of the interconnect, and the signal passing though the interconnect is not longer biased. Slick.
One could even do this with a SB2/3 running directly into a poweramp. Use the digital volume control and take the output via the analog output, bypassing the output caps. The dac and/or opamps are running single rail, and the outputs, sans cap, never cross ground.
