MSB Technology Platinum DAC III Скачать руководство пользователя страница 3

Страница: 3 / 12

Unique Technology - the past and the future

Over 10 years ago early DACs were all 16 bit ladder DACs, with a precision laser-trimmed
resistor creating the appropriate analog level for each of the bits. The DACs worked well and
sounded good. They were quite expensive as very accurate resistors were required. Then along
came the “single bit” DACs. Rather than using a resistor to create an analog level, pulse width
modulation was used. Basically each bit was created by turning a switch on and off for the
appropriate length of time. The resulting square wave pattern was filtered to create a smooth
output. The expensive resistors were gone, and so was the good performance. Next came the
Delta Sigma DAC. It used the same pulse width modulation but rather than creating a single
large pulse for each data point, the data point was created with many small pulses. This allows
the pulses to be smoothed with a less radical filter, and improves the sound. As you can see,
upsampling the input signal to a higher frequency reduces the filtering requirements and thus
improves the sound. This is the current state-of-the-art as exemplified in the LINK DAC III with
the upsampling option.

The Platinum draws from the older, superior ladder technology, but with incredible improvements. The Platinum contains four 24 bit MSB
DAC modules (seen below). The Platinum is fully balanced so there
is a matched pair of 24 bit DAC modules for the inverted and non-
inverted signals on each of the right and left channels. Finally, each
DAC module contains one R2R ladder DAC with a 23 bit negative
sign and one R2R ladder DAC with a 23 bit positive sign. Together
this makes a true 24 bit DAC. This design allows the quieter moments
in your music to be true to the music, without the linearity errors near
zero that plague normal ladder and delta-sigma DAC designs. With
a dual 24 bits of combined resolution, a 24 bit source gives a true 24
bit resolution without the losses and errors that make your normal 16
or 24 bit DAC perform far less than their actual resolution (normal 16
bit DACs only muster a meager 12 bits of resolution). The Platinum
is carefully designed so as to require no DC correction in the output
stage. This allows direct DC coupling on the output stage for pure,
uncolored sound -- with no output filtering to muck up your high end
or smear your bass attack. And for those who require a balanced
analog output, the separate positive and negative DACs directly
drive the balanced outputs, with no analog output stage at all!

Another major difference in the Platinum is the type of output.
Essentially all ladder DACs produce a current output. This is
converted to a voltage output with a current to voltage converter.
This problematic circuit colors the sound and introduces non-linearity.
The Platinum is a true voltage DAC with a voltage output right from
the source. All amplifiers have slew rates greater than 1000 Volts/
microsecond. The output impedance of the Platinum is 50 ohms.

Special Features

The DAC III has many special features. The following sections discuss these features and how they work.

Upsampling and filtering

As MSB technology has developed, so has our DAC architecture. Our advanced digital
filter now replaces the asynchronous upsampling of earlier models. The 16X Digital filter
goes way beyond our older 4X upsampling. To play a 24/192 disc the Platinum only needs
to be plugged into a DVD-A player with an MSB XPORT output. The new upsampling
feature dynamically buffers and re-clocks all the data and clock signals to provide a virtually
jitter-free source directly to the DACs.

The selectable digital filter response permits the user to choose the filter design they prefer.
It allows for the selection of a standard brick-wall filter or a slow roll-off filter, both at half
the sampling frequency. Each provide a distinct, glorious listening experience. You may
favor one or the other, or enjoy changing the filter response to suit the music you listen to.
Music with less high frequencies may benefit from the slow roll-off filter.

To play a 24/192 disc the source player needs to have an MSB Network or XPORT output.
If your DVD-A player does not have the MSB Network output, it can be added. A 192k
input will override the upsampling settings.

Cus

Cust

tom MSB Digit

om MSB Digit

om MSB Digital F

al F

al Filt

ilt

ilter

The DAC III has a custom DSP based Digital filter and clock module. This breakthrough
technology is new in the DAC III. For the first time ever, we have created our own Custom
Digital Filter for the Platinum DACs. Previous versions of the Platinum DAC used the Burr-

IGN

AVE

, 19.95

TEST

TONE

COPE

SETTINGS

2 V/

DIV

, 10

USEC

DIV