Rostec Engineering Administration: Christianehøj 43, 2860 Søborg, Denmark - Email firstname.lastname@example.org - Phone +45 3967 6438
ROSTEC AD8 A/D Converter
High Performance 8 channel 192 kHz 24 bit A/D Converter
Electrical and mechanical specifications
Analog to Digital interface.
* 8 balanced analog line inputs at the back panel, D-SUB 25 female, TASCAM STANDARD.
* 4 transformer balanced AES3 outputs (8 channels) at the back panel, D-SUB 25, YAMAHA STANDARD.
* 1 USB 2.0 Digital interface, TYPE B connector.
* The USB connection is compatible with Mac OS X 10.6.8 or later. Windows is not supported.
* AD Resolution: 24 bits.
* Sampling frequencies: 44.1k, 48k, 88.2k, 96k, 176.4k, 192k.
* AES latency: less than 0.2 mSec.
* USB latency: down to 1.5 mSec (3.0 mSec roundtrip) This is highly dependent on the host computer speed and sampling frequency.
* Inter-channel Gain Mismatch: 0.1 dB.
* Linearity inside passband (passband ripple): 0.035 dB.
* Frequency response: 2nd order analog anti-aliasing filters at 1 Hz - 120 kHz +/- 0.2 dB. Brick-wall digital filters at 0.5 x Fs
* THD+N: 0.00045 % (-107 dB) at 1 kHz.
* THD: 0.00015 % (-116 dB) at 1 kHz (see detailed FFT distortion analysis in the manual).
* Crosstalk between adjacent channels: -105 dB, 20 Hz - 20 kHz.
* Noise: 115 dB RMS, A weighted, 10 Hz - 22 kHz measurement bandwidth.
* Analog input level: +18 dBu +/- 0.2 dB (EBU standard), switchable to +10 dBu +/- 0.2 dB (for vintage mixing consoles, equipment etc).
* Analog level accuracy, calibrated version: +/- 0.01 dB.
* Analog input headroom: + 30 dBu.
* Hum residue from analog power supply, 1st, 2nd, 3rd and 4th harmonic: less than -136 dB referenced to 0dBFS.
* Word clock input:: BNC, unbalanced, unterminated (1.5 kohm), min. 0.2 Vpp, max. 10 Vpp.
* Word clock output: BNC, unbalanced, impedance 75 ohm, 5 Vpp no load, 2.5 Vpp into 75 ohm.
* Internal AES GRADE 2 crystal oscillator.
* Temperature stability: +/-2 ppm from 0 degC to +70 degC.
* Ageing: 2 ppm per year.
* Word clock frequencies: 44.1k, 48k, 88.2k, 98k, 176.4k, 192k.
* Internal crystal oscillator jitter: 2 ps rms.
* Word clock output jitter: 50 ps rms.
* AES data jitter: 50 ps rms.
* Clock input capture range: +/- 80 ppm.
* Lock time approx: 0.2 - 0.4 sec.
* Linear analog, passively cooled, high power, very low noise.
* Thermally and overload protected.
* Mains voltage: Nominal 230 VAC, range 180 - 264 VAC 50-60 Hz (115 VAC version available by request).
* Power consumption: 12 Watts.
* Sturdy steel casing, magnetically and electrically screened. Size 210 mm x 210 mm x 42 mm.
* Analog and digital circuits are magnetically and electrically isolated by internal metal screening and separate ground systems.
* All digital inputs and outputs are ESD protected to 23 kV 15 A surge (IEC61000-4-2 and IEC61000-4-5).
* All analog inputs are ESD protected to 2000V, human body model.
AD8 is a truly high performance 192 kHz 24 bit A/D converter in a half size 19”magnetically shielded metal
enclosure. It features High-End true class A analog circuits with the same transfer characteristics as vacuum
tubes, and a state of the art Analog to Digital Conversion with impressive specifications and exquisite sonic
It connects directly to your favourite DAW via a bit-perfect and class-compliant USB interface. At the same time it
features AES3 transformer balanced outputs aimed at professional studio/broadcast equipment.
The user interface is straight forward and intuitive with at clear “What You See Is What You Get” readout on a
bright OLED display.
A high accuracy calibrated version is available intended for industrial measurements and processing.
Click for larger pictures
With its true class A and carefully designed analog circuitry, Rostec AD8 represents a sound quality that is far above what you will find in
the standard digital interfaces flooding the market today. AD8 is constructed with a throughout balanced architecture, meaning that audio
signals, analog as well as digital, are routed internally as balanced signals, and all analog signal switching is performed by hermetically
sealed relays with gold contacts. There are no digital analog switching, no digital level adjustments, and there are no digital processing,
except from the AD conversion process.
The analog circuit features a soft clipper with a threshold just a little bit above digital clipping. This means that you can ride the converter
hard and continuous at the clipping level in your DAW without getting the ugly sound break-up so well known from standard digital
interfaces and sound cards. At the digital clipping level, the analog circuit still has an extra headroom of 12 dB above the digital clipping.
Also, the power supply is pure analog for a quiet and noise-free environment. We want none of that severe digital noise pollution from
switch mode power supplies, thank you!
This is a purists dream come true. And you can hear it!.
This highly sophisticated design gives AD8 a large dynamic range, huge headroom and ultra low noise and distortion, and the result is a
beautiful relaxed, open, warm and natural sound, with an impressive amount of details and an astonishing depth and perspective. Gone
is the ugly, cold, flat and lifeless sound you get from the typical standard digital interfaces or sound cards. This is classical analog quality
at its very best, and digital technology used wisely.
Readings for audio enthusiasts:
In the design of AD8, special care and attention has been paid to maintain the linearity of the dynamic range, all the way down to the level
where the signal drowns out in the circuit noise.
Maintaining the absolute linearity at the low end of the dynamic range is essential for allowing the human ear to detect the environment
correctly. Back in the stone age humans were depending on their hearing to detect precisely from which direction the attack of the tiger
came, and this information is mostly found in the low level parts of the sound.
Many years have passed, but we still have this ability, and we use it when we listen to music and pin-point the position of the musical
instrument and performers. Maintaining this in the AD conversion process is mandatory for getting the full experience of the music.
In most digital interfaces, this lower portion of the audio signal is polluted with digital noise and non-harmonic ground based noise (from
switch mode power supplies and digital processing), which means that the ear detects this part of the signal as sound garbage with no
clear relationship to the music. The result is, that the environmental information is degraded or partly lost, and the ear loses portions of
the depth and perspective details, giving the music a flat and dimensionless expression.
• 8 channels of Analog to Digital conversion to the DAW via USB, and/or directly to the AES outputs.
* 8 channels of Digital from the DAW routed via USB directly to the AES outputs.
• 192 kHz 24 bit high-end latest generation converters.
• Dynamic range 115 dB (higher internally, but limited by opamp noise).
* USB 2.0 class compliant bit perfect interface.
• Transformer balanced 110 ohm AES outputs.
* Industry leading Low Latency performance.
• Easy interfacing via standard D-sub 25 and USB B connectors.
• Internal low jitter Grade 2 word clock generator.
• Exceptional high immunity against jitter and digital noise from computer work stations.
• Word clock Input has an automatic "sweet spot" detector, providing auto-slicing and signal clean-up.
• Word clock input accept from 0.2 Volts to 10 Volts.
• Electronically balanced analog input buffers.
• Analog JFET and BJT cascode technology with the same characteristics as vacuum tubes for exquisite sonic performance.
* Analog level signal switching by hermetically sealed relays with gold contacts.
• Analog and digital true balanced architecture throughout the unit.
• Linear low noise analog power supply.
• Internal magnetic and electrical screening.
• Digital Inputs and outputs are ESD protected to 23 kV, IEC 61000-4-2 and 15 A surge, IEC 61000-4-5.
• Sturdy steel metal casing, half size 19” 1U height.
• Affordable price. High value for money.
Two units fit nicely on a 19” rack shelf