Clean power for hi-fi...
The James Audio mains conditioner provides the power needed for your h-ifi system to perform at its best and does this without the negative effects that some conditioners introduce....
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If you would like to find out more, talk to the designer or take advantage of our 30 day no quibble home trial, please email us with details of your system and any mains problems you are experiencing.
News
The new Mk.6 mains conditioner was in action at the Bristol Sound and Vision show and helped Neat Acoustics win the BFA Best Stereo Demonstration award. Neat used a clever combination of acoustic panels and the James Audio power conditioner to overcome some of the main barriers to good quality sound at a hi-fi show.
James Audio 1kVA Power Conditioner - Model FIDT6FS
The power conditioner is suitable for hi-fi systems with a total RMS output power up to 600W (250W in the case of pure Class A power amplifiers). It can easily supply the additional requirements of several hi-fi separate sound sources.
It offers the combined advantages of isolation transformers and high attenuation filters but overcomes the limitations of either and brings many additional benefits:
Output sockets
Power at the output sockets is galvanically isolated from the mains network by a custom-built isolation transformer, incorporating an earthed screen between its input and output. This component is at the heart of a complex wide-band filter.
Output voltage
The output is a nominal 240V, balanced about earth but without a hard connection to earth. This is a better configuration than normal mains, where neutral is tied to earth, causing noise mode-conversion due to asymmetric impedance.
Low frequency filtering
The low frequency filtering extends far below the 150kHz lower limit of current EMC legislation. The audio and ultrasonic bands, to which hi-fi equipment is intrinsically sensitive, are also addressed (see graph above). The differential-mode (live to neutral) filtering has a roll-off frequency below 250Hz, i.e. below the 5th harmonic of the 50Hz mains.
Isolation transformer
The isolation-transformer permits the use of sufficient common-mode filtering capacitance to earth on the output side. (This could not otherwise be achieved without creating incompatibility with safety earth-leakage breakers.) The common-mode (live + neutral to earth) filtering is so good that the C-M test signal injected at the mains input port was below the lower resolution of the RF millivoltmeter connected at the output between DC and 100kHz. (See graph above)
RF filtering
The construction uses a custom EMC enclosure and RF techniques to ensure that the filter is not by-passed at radio frequencies but remains effective into the microwave region. Both the transmission modes were measured using a spectrum analyser with tracking generator and pre-selector. Over the measurement range, 100kHz to 1800MHz, the attenuation remains above 60dB, i.e. less than one millionth of the RF noise on the mains gets to the outputs.
Low output impedance
The output impedance is very low, due to large values of high pulse-rated differential capacitance. The source-impedance remains low as frequency increases and allows the sourcing of high transient currents.
Transformer hum from DC on the mains
The power conditioner can eliminate the annoying acoustic ‘buzz’ which is occasionally heard from the enclosure of some hi-fi units, especially amplifiers. This is caused by low levels of DC on the mains, due to single-rectifier loads, such as a hairdryer on the ‘low’ setting. It can push the magnetic circuit of a toroidal power-supply transformer into the saturation region, causing a dramatic increase in audible noise.
Noise coupling
Each output socket has a local filter block, linked to a central distribution block. This reduces the noise coupled between hi-fi separates and can prove especially beneficial if some units have a switch-mode power supply (smps).
Protection from mains spikes
The conditioner includes over-voltage clamping, as well as 4.4kV galvanic isolation, so hi-fi equipment connected via this unit enjoys considerable protection from potentially disastrous high-voltage transient events on the mains.
