Benefits of balance power / isolation transformer with balance output
As a revision, a typical household mains is 240Vac (or 120Vac) referenced to ground. The neutral line is actually connected to ground at some point of the wiring in or before the house. Balance power is to have out of phase +120 and -120Vac at live and neutral lines, where it still show 240Vac when measured across both terminals +120Vac – (-120Vac) = +240Vac, and is seen by connected equipment to be no different than a normal 240Vac power.
What is the benefits of having balance power?
- It provides very, very low noise floor in the connected electrical / electronic devices.
- The connected equipment / systems can see increase of as high ~8x-10x dynamic range.
- Power supplies does not have 100% efficiency. Portion of the returned energy are channeled back onto the source (mains/transformers) as electrical noise.
- These returned energy cause ground noise, and is bad as all the signals are grounded to this same polluted ground line. Visualize this:
- All your signal cables, power cords, speaker cables, analog and digital circuits have ground pin/cable and all are shunted to ground to get rid of all the noises picked up along the way, and to use the ground as ground-reference. How important do you think it is to have a clean ground?
- The more front end the gear is, the more important it is to have better power because the signal level is lower and the gain is higher.
- If noise floor is high, SNR (signal-to-noise ratio) will need be low.
- If gain is high, any noise will be amplifier significantly.
- With conventional mains power, the returned energy rides on the neutral (a.k.a. ground) line, thus polluting it with electrical noises (voltage ripples or current spikes).
- With balanced mains power – returned energy stays at only live and neutral lines, and is cancelled at ground (center) line. Equal and opposite (out of phase) returned energy cancels each other, thus keeping the ground free of electrical noises.
- The better the power balance, the better the noise cancellation, and the wider the noise rejection bandwidth. Therefore the design of the balance isolation transformer for absolute balanced output is critical to the noise rejection.
- Even so, a normal balanced transformer will yield better results than a normal transformer.
- Better clarity, clearer stereo imaging, more details unearthed, blacker blacks, darker background, and higher contrast.
- If you feel that your equipment sounds and look better at a certain time of the day or night, that means you are affected by the mains and balanced power will help.