Types of Noise
There are many forms of noise that a Hi-Fi or AV system can be subject to or even produce.
If the actual pieces of equipment are buzzing this is generally one or more of the following:
- poor transformer design or construction
- Use of a product not designed for the users' power line frequency
- Poor mechanical mounting of the product
- An over-voltage mains supply
- A significantly distorted mains supply
- DC present on the mains supply
If there is noise from the speakers then it may be one or more of the following:
- Poor noise performance of one or more of the pieces of equipment
- Incorrectly matched sensitivities between products (e.g. power amp too sensitive for a pre-amp, speakers too efficient for a power amp)
- Under voltage supply (may cause regulators within a product to drop out of regulation)
- Earth grounding loops
- No earth
- Poor or high impedance earth
- Significant distortion of the mains supply
- Significant mains born or environmental RF present
- Significant electromagnetic field present, which can effect the equipment or the cabling.
All Isol-8 mains filters act to reduce mains-born wide-spectrum noise. The frequency and degree of attenuation depends on the model; each Isol-8 unit delivering better results as one progresses up the range. In addition, Isol-8 models with isolation transformers will, to a large degree, stop DC from passing to the equipment at the expense of some mechanical noise if the DC content is very high. Only complete regeneration can provide an absolutely pure waveform, devoid of any aberrations.
It must be remembered that much of the acoustic improvements that mains filtering bring about is due to what we don't actually hear. No piece of equipment is perfect and even a small amount of mains born energy other than the 50 or 60Hz fundamental can have a significant deleterious effect on how the equipment handles the actual audio (or video) signal passing through it. This is particularly significant with 'high gain' kit where there is only a millivolt signal level to begin with.
© 2008 ISOL-8 Teknologies Ltd. Tel: 020 8856 8856
www.intergage.co.uk
