MEDUS d/a converter

//MEDUS d/a converter
MEDUS d/a converter 2017-04-22T06:46:16+00:00
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MEDUS d/a converter is Weiss new flagship digital to analogue converter.

  1. Standard Version HKD$168,000
  2. DSD/USB or DLNA option. HKD$188,000
  3. DSD/USB and DLNA option. HKD$198,000
  • Remote control for volume and other DAC setting (including 32dB max. output level trim)
  • Extremely high quality DSP + preamp section by 2nd generation OP2-BP (Exclusive for MEDUS)
  • New front LCD panel for clear input selection, format, sampling rate, filter and volume.
  • New power supply with “Mu-Metal” transformer enclosure.

Medus-PCM-input

e.g. Input 1 / Input resolution 24Bit/176.4kHz / -14.0dB volume / Filter: A

Medus-DSD-input

e.g. Input 3 (USB) / Input resolution DSD / -12.5dB volume / Filter: A

Medus-PCM-input

e.g. Input 1 / Input resolution 24Bit/176.4kHz / -14.0dB volume / Filter: A

Mechanics
The MEDUS employs a twin metal frame. The inner chassis is made of steel and acts as a very effective shield against electrostatic and electromagnetic radiation. The outer frame is made of massive anodized aluminium for additional shielding, resulting in optimal heat convection and beautiful looks.

Power Supply
A powerful non-switching power supply is used. All sensitive voltages have their own regulators which are separated between left and right channels. The result is an analog output free of “digital noise” and channel crosstalk. The power switch activates a semiconductor relay which only switches on or off at zero crossings of the mains voltage. This assures a glitch free power switching. The mains transformer sits in a mu-metal shielding box.

Synchronization
The MEDUS is synchronized by the input signal present at the selected input. Several signal re-clocking schemes are combined for extremely high jitter attenuation down to subsonic frequencies, making the MEDUS virtually immune to jitter. With the USB or Firewire inputs the master clock is generated by the MEDUS.

Digital Inputs
There are a total of four inputs with the following input sockets:

  • Input #1: AES/EBU on XLR or RCA
  • Input #2: AES/EBU on XLR or RCA
  • Input #3: AES/EBU on XLR or USB
  • Input #4: AES/EBU on TOSLINK/DLNA or RCA

Sampling frequencies can be 44.1, 48, 88.2, 96, 176.4 or 192 kHz. Inputs #1 and #2 can be used for the dual wire scheme of transferring 88.2 kHz…192 kHz data. All inputs accept up to 24 Bits of data word-length. Optional inputs are Firewire or ST type glass fiber.

Up-sampling
Signals at 44.1 or 48 kHz sampling frequency are up-sampled in the MEDUS’ DSP chip, using our own up-sampling algorithms. Thus the DAC chip always receives signals at a 88.2 kHz minimum sampling frequency.

Converters
The 32 Bit DAC chip up-samples the input signal to about 1.5 MHz. Four D/A conversion channels are used per audio channel, resulting in exceptional performance specifications. The I/V conversion after the DAC chip uses two of our own discrete OP-AMPs (the OP1-BP) per channel.

Analog Outputs
MEDUS analog processing is done with our own 2nd generation discrete operational amplifier modules, the Weiss OP2-BP. The OP2-BP is arguably the best audio operational amplifier currently available. Four OP2-BP are used per channel, two for current to voltage (I/V) conversion and two for the balanced and unbalanced output stages. The OP2-BP run in class A mode for all common loads. Output levels can be set with a rotary switch at the back of the unit. The level range is 32 dB with a 1 dB step resolution. The outputs are symmetrical on XLR connectors and asymmetrical on RCA connectors. No sound degrading servo mechanisms or AC coupling capacitors are used.

Front panel controls
The power switch allows to switch on or off the MEDUS unit. Four switches select one out of four input sources. A display conveys information on the selected input, the sampling frequency, the output level, the oversampling filter type, the absolute output polarity, the mute status and the coarse output level setting

Remote Control
Allows to control all functions of the MEDUS, namely: The input selected for conversion, the output level, output muting, the coarse output level, the absolute polarity, the oversampling filter type, the display brightness.

Back panel elements from left to right

  • Analog outputs on XLR and RCA connectors with output level switch.
  • Digital inputs 1…4 (three XLR, three RCA, one USB and one TOSLINK connector).
  • Mains connector with fuses and voltage selector.

Optional back-panel elements

  • Firewire connector.
  • ST type glass fiber connector.

Power

  • Mains voltage: 100…120 / 200…240 Volt
    Fuse rating: 500 mA slow blow
  • Power consumption: 80 VA max.
  • Power consumption in standby: 2 VA max.

Size

  • Depth: 30 cm
  • Width: 45 cm
  • Height: 6,6 cm
  • Height with feet: 7,4 cm

Size Remote

  • Depth: 2,5 cm
  • Width: 6,2 cm
  • Height: 16,9 cm

Available Color
Silver, Black

Digital Inputs

  • (3) XLR connectors
  • (1) TOSLINK connector (optical)
  • (3) RCA connectors
  • (1) USB connector
  • All inputs accept professional or consumer standard, i.e. accept AES/EBU or S/PDIF signals
  • Sampling frequencies; single wire scheme: 44.1kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz or 192 kHz on any of the four inputs
  • Sampling frequencies; dual wire scheme: 88.2 kHz, 96 kHz, 176.4 kHz or 192 kHz on inputs 1 and 2
  • DSD64/DSD128/PCM384kHz : On USB input
  • PCM192kHz: On DLNA input
  • Sampling frequency tolerance: ±80 ppm
  • Maximum input word-length: 24 Bits

Analog Outputs

  • (2) XLR Connectors
  • (2) RCA Connectors
  • Servo-less, DC coupled, short circuit proof output circuitry
  • Output impedance: < 100 Ω
  • Output level: variable from −4.0 dBu to +27.0 dBu balanced on XLR connectors (−10.0 dBu to +21.0 dBu unbalanced on RCA connectors) with 0 dBFS input, in 1 dB steps (−4 dBu is 0.49 V, +27 dBu is 17.35 V, −10 dBu is 0.245 V, +21 dBu is 8.67 V)
  • Output stage: Discrete Class A

D/A Converter chip

  • Over-sampling multi-bit sigma-delta converter
  • Four converters per audio channel

Synchronization

  • Synchronized via the input signal
  • Extremely efficient Jitter attenuation down to subsonic frequencies
  • Sampling frequencies: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz

DSP algorithms

Up-sampling, jitter reduction

Measurements
The measurements below have been taken at the following conditions (unless noted otherwise): 1 kHz, +24.0 dBu output level (−3 dBFS input level), 192 kHz sampling frequency (fs).

Frequency Response:

  • Fs = 44.1 kHz: 0 Hz…20 kHz: within ±0.25 dB
  • Fs = 48 kHz: 0 Hz…20 kHz: within ±0.25 dB
  • Fs = 88.2 kHz: 0 Hz…30 kHz: within ±0.75 dB
  • Fs = 96 kHz: 0 Hz…30 kHz: within ±0.75 dB
  • Fs = 176.4 kHz: 0 Hz…40 kHz: within ±0.75 dB
  • Fs = 192 kHz: 0 Hz…40 kHz: within ±0.75 dB

Signal To Noise Ratio (SNR) at −40 dBFS input:

  • > 129 dB un-weighted
    (relative to full scale output)
  • > 132 dB A-weighted
    (relative to full scale output)

Linearity:

  • At 0 to −100 dBFs input level:
    < ±0.05 dB deviation from ideal
  • At −100 to −120 dBFs input level:
    < ±0.2 dB deviation from ideal

Total Harmonic Distortion plus Noise (THD+N) ratio:

  • < −112 dB @ −3 dBFS input
    (0 dBFS = +27.0 dBu)
  • < −115 dB @ 0 dBFS input
    (0 dBFS = +27.0 dBu)

Crosstalk:

  • < −110 dB, 0.20 kHz

OP2-BP: ( Exclusive for MEDUS! )
Eight OP2-BP modules runs in Class A outputs. 4pc as I/V conversion, another 4pc as full balanced output stage. The output levels can be set between -infinity and +27dBu. OP2-BP is the new generation of OP1-BP. There are different in parts and layout. You may look at the follow 2 graphs to see the different. If you would like to read more about the OP1-BP, please click here: Weiss OP1-BP amp stage.

Power Supply:
All sensitive voltages have their own regulators which are separated between left and right channels. The result is an analog output free from “digital noise” and channel crosstalk. A new “Mu-Metal” main transformer enclosure adds max isolation between sensitive section.

Mechanical Design:
The MEDUS employs a twin metal frame. The inner chassis is made of steel and acts as a very effective shield against electrostatic and electromagnetic radiation. The outer frame is made of thick anodized aluminium for additional shielding, for optimal heat convection and for beautiful looks of course.

Medus+MAN301

 

OP2-BP

Same with THD vs level, there you can add the input level (horizontal axiss) and the measured THD+N to get the THD+N relative to full scale. As an example at -60dBFS the THD+N is -70dB, so the THD+N relative full scale is -130dB. This THD+N figure,we cannot use and DAC-ADC method to measurement.

The linearity graph is incredibly good.

Crosstalk

It is impossible to measure the (THD+N) quality of MEDUS with the DAC – ADC approach. One has to do it as shown in the above thd-fft-96.gif file. There the 1kHz signal has been suppressed in the analog domain via the AP system (as it is done in a THD measurement, you see the dip around 1kHz caused by the notch filter which notches out the 1kHz tone). This signal then is A/D converted and a FFT is done. Because the 1kHz signal is suppressed, the dynamic range of the signal is much less, i.e. just the harmonics and noise and thus the A/D converter does not have to process a huge dynamic range. The AP then recalculates the proper scaling as if the 1kHz tone was still there. So the 3rd harmonic in the graph is more than 120dB below full scale.