The Article
The Air Audio Balanced Mains Power Supply: power without the noise
4th April 2017
A 2kVA balanced transformer with multi-taps for 220, 230,240, 250 VAC voltage inputs. The power is supplied by a large, low impedance balanced output transformer with an earthed centre-tapped secondary. The transformer core is run at reduced flux density, is impregnated with varnish and the centre ‘hole’ resin filled to reduce mechanical buzz. This is then isolated within a 4mm thick damped aluminium case with further damping panels internally
This balanced transformer configuration produces an output voltage consisting of a symmetrical pair of identical but out-of-phase voltages (i.e. the two ‘live’ wires are inversely phased and like balanced signal wires). The company say that there is a reduced noise floor because, “… at the central earth point these equal and opposite currents meet and cancel each other out, they are not superimposed on the earth. This is known as ‘common-mode rejection’.”
Balanced mains power is used in almost all recording studios, to provide the lowest noise floor but only now is this technique becoming accepted in the home audio and A/V world. Power amplifiers are generally less improved audibly than digital source components, phono-stages and pre-amplifiers, “Large power amplifiers require their own dedicated balanced supply in our opinion,” said the company. “Practically, we suggest all digital and low signal level source components should be powered through one of our balanced transformers, alongside integrated amplifiers up to say 100W/channel.”
Features include a low hum transformer, supported on a vibration isolation platform inside substantial damped aluminium casework for minimum noise as all times and a switchable output balanced voltage display. The supply also arrives with anti-surge electronics to prevent fuses blowing when it is turned on while the unit can be used with any additional passive distribution blocks and/or RF/EMI electronics. Spanning 180mm x 230 x 330mm, the unit weighs in at 16Kg. Price is £1,400.
To learn more, click www.airaudio.co.uk or call 01491 629629.
Hi Paul: Now this baby is worthy of an evaluation; we know precisely its mode of operation (i.e. technology employed -to tackle AC line noise).
pj
I’ll try and grab one – thanks for the reminder, Peter, in all the commotion, it had slipped on by.
Hi Paul: When I read the following:
“.Power amplifiers are generally less improved audibly than digital source components, phono-stages and pre-amplifiers, ‚ÄúLarge power amplifiers require their own dedicated balanced supply in our opinion,‚Äù said the company. ‚ÄúPractically, we suggest all digital and low signal level source components should be powered through one of our balanced transformers, alongside integrated amplifiers up to say 100W/channel.‚Äù
It tells me that the company knows a thing or two; a single AC power supply (such as a single large 1.5-2.0 KVa transformer) although a most welcome addition for use with premium hi-fi, is not the end-all, be-all for those seeking the best sound possible. For that, multiple Balanced Supply’s and/or Bal. with AC-Re-generation (digital components) goes a long way in extracting the finest performance from our beloved hifi’s.
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pj