Audes ST-1500 Power Conditioner

Using ST-1500 with any AV equipment, including both solid state and tube devices, improves the quality of sound reproduction. The most significant results are achieved when the power conditioner is used with power amplifiers. During highly dynamic parts of an audio track (e.g. tutti fortissimo of a full symphonic orchestra, sounds of large ethnic drums, bass parts of experimental electronic music, cinematic SFX) a powerful amplifier must draw substantial current surges from a power supply unit, which can reach magnitudes of 50–100 A, while maintaining voltage levels without dips. An ordinary domestic socket, which is connected to a distribution board using long electrical cables, is not capable of providing such current levels due to relatively high output impedance. ST-1500 has a very low output DC resistance therefore it can easily supply high current surges without facing voltage dips. This is achieved by using a transformer with a very large core resulting in a very small magnetic flux density. In turn the response time of a power amplifier to a changing audio signal is reduced, which benefits reproduction of transients, especially in lower frequency bands. An audio reproduction system exhibits a wider dynamic range, which results in more realistically sounding musical instruments and cinematic SFX.

Another problem in power supply of high-quality equipment is noises in electrical networks. They appear when switches and controllers of electrical motors, dimmers and regular lighting, as well as switch-mode power supply units of modern AV equipment are used nearby. High-quality CEE 7/3 sockets are galvanically isolated from an external electrical network. The transformer is equipped with a reliable electrostatic shield. Arriving electrical interferences are counteracted using a mutual cancellation principle. The secondary winding of the transformer is separated into two halves and has an artificial centre tap, which is connected to the earth clips of each socket outlet. The ST-1500 transformer was designed to work as low-pass filters with a cut-off at 800 Hz, since all electrical network interferences happen at much higher frequencies. Secondly, the filtering effect is caused by self-inductance of a very large core, because of which magnetic flux cannot change instantaneously under a transient disturbance. All of the above technical aspects allow to almost entirely remove electrical network noises providing reliable high-quality power supply to audio equipment.

When the power conditioner is first switched on the transformer is subject to an inrush current of approximately 20 A during magnetisation of the transformer core. Due to this a soft start is implemented into the power conditioner. A special ballast resistor limits the current surge, so that other electrical equipment, which is connected to the same electrical network, remains unaffected.

Audes power conditioners have an overload protection and a thermal protection, which switches the transformer off if temperature of the transformer reaches 90 °C. Once the temperature drops to 75 °C the device will reconnect to the electrical network automatically. The transformer was designed to maximise the number of turns in the primary winding. Because of this under the no-load condition the power consumption of ST-1500 is low.

The normal operating ambient temperature range for ST-1500 is 10–25 °C. At lower temperatures additional heating is required to prevent condensation. At higher temperatures additional external cooling is required.

ST-1500 produces virtually no acoustic noise, which allows its use not only with domestic High-End audio equipment, home cinemas and show rooms, but also in sound recording studios.