AVM Evolution CD3NG Manual de Instruções - Página 4

Procurar online ou descarregar pdf Manual de Instruções para Leitor de CD AVM Evolution CD3NG. AVM Evolution CD3NG 10 páginas.

1. Basic information about the CD3NG

The case is fully made of steel. This material acts as a shield and protects drive and circuitry against

interferences from external magnetical and electrical fields. The audio-connectors are all gold plated to

minimize electrical losses and provide long lasting perfect contacts.

A toroidal transformer together with 10.000µF of capacitance supplies the power for the CD3NG's circuitry.

All voltages are well regulated to avoid hum and are additionally buffered by large capacitors directly in the

circuitry where they are needed.

The disc is read by a drive especially made for CD. It can theoretically read CDs at 2 times the normal

speed. Thus the positioning of the laser pickup and the focus regulation can act very quick. So the drive

never comes to it's limits when reading audio CDs at normal speed. Besides normal audio compact discs the

drive can also read CDROMs and some CDRWs.

The CD3NG is equipped with upsampling circuitry and highly precise a/d converters. The theory of function

will be described in the following text. If You are not interested in technical details, skip these chapters and

simply listen to the music coming from the CD3NG. You will discover Your CD collection anew! And that is

what we want to achieve. Because application of new technologies is not just a gimmick but offers audible

and measurable advantages to the listener.

The quantity of information on a CD is defined by the audio format of 44,1 kHz sampling rate and 16 bits of

resolution. Additional informations (i.e. higher resolution or bandwith) cannot be created by any electronic

circuitry playing back such a CD. It is a fact that conventional d-/a converter systems do not fully reproduce

the given information. This has several reasons: Converting a digital signal to an analogue signal produces

analogue noise. This is because the digital (quantized) values which represent the signal are discrete with a

very fine – but nevertheless limited - resolution. Therefore exist slight deviations in respect to the analogue

original signal which was continuous (means infinite resolution). These deviations are random and cause an

additional noise to the original signal when it is converted from the digital domain to the analogue domain.

This kind of noise is called quantization noise.

The characteristic of this noise is that it has an energy which depends on the resolution used to quantize the

original signal and which is continuously spread over the whole range of the sampling frequency bandwidth.

It is obvious that this noise can mask fine details of the originally recorded music.

For physical reasons it is not possible to avoid quantization noise. Also a reduction of the total noise energy

is not possible because the noise has been created when the signal was recorded. An elegant solution of

this problem is to increase sampling frequency when re-converting the signal from digital to analogue. The

upsampling converter installed in the CD3NG can increase sampling frequency from 44,1 kHz up to 192 kHz.

When re-converting the upsampled signal the upsampling converter produces the same amount of noise

energy as a conventional converter.