ADC2

The ADC2 is the successor of our renowned two channel ADC1-MK2 A/D Converter. It uses state of the art A/D chips in our proven "correlation technique" configuration, which lowers converter imperfections. The analog input stages are kept balanced from the input connectors throughout to the converter chips. A high quality microphone preamplifier is built in as a standard feature. AES/EBU and optional Firewire outputs work at up to 192 kHz/24 Bits.

INPUTS:

The ADC2 sports two separate input sections, one stereo pair for line level signals and one stereo pair for microphone level signals. The microphone input can be high pass filtered to cut off rumble noise. A 48 V phantom power source can be switched to the microphone inputs. After a relay controlled attenuator circuit, which uses 1 dB steps over a range of 42 dB, the signal hits the A/D converters. The analog input stage is kept balanced from the XLR connector to the A/D chips.

CONVERTERS:

Two converter channels are used per audio channel which enhances the conversion quality. The analog to digital conversion process can run at 44.1, 48, 88.2, 96, 176.4 or 192 kHz. The parameters of the two conversion channels can be set independently, except for the sampling frequency and the POW-R dithering algorithm.

SYNCHRONIZATION:

Synchronization can be from an internal crystal oscillator or external through AES/EBU (XLR) or word-sync (BNC) connectors. The AES/EBU synchronization input can also be used as a digital audio input. This allows to use the ADC2 as a peak limiter and/or POW-R dithering processor for digital audio signals.

PEAK LIMITER:

The built in digital peak limiter allows for setting a generous headroom on the analog inputs and still get a full scale signal at the converter's output. In addition to the peak limiter with a threshold parameter there is a digital gain control.

OUTPUTS:

The output word-length can be reduced from 24 to 16 Bits with the built in POW-R dithering. It is possible to have one output running at 24 Bits and another one at 16 Bits. The output formats are AES/EBU in one or two wire technique, S/PDIF in single wire as well as Firewire for a direct connection to computers. The Firewire connection can also be used to feed a signal from the computer to the S/PDIF output of the ADC2.

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METERING:

For metering a large bar graph shows the level to the A/D input, the output level, overload conditions and the gain reduction in the aforementioned peak limiter. The peak hold meter with numeric readout can be used to monitor a transfer and check for overloads which may have occurred.

POWER:

Mains voltage: 115 V or 230 V with voltage selector

Fuse rating: 630 mA slow blow

Power consumption: 60 VA max.

SIZE:

Depth: 30 cm

Width: 43,3 cm (19")

Height: 4,4 cm (1HU)

ANALOGUE LINE INPUTS:

Two channels on two XLR female connectors, pin 2 hot

Symmetrical, not earth free

Input impedance > 5 k

Analogue Microphone Inputs

Two channels on two XLR female connectors, pin 2 hot

Symmetrical, not earth free

Input impedance > 5 k

48 V phantom power switchable

AES/EBU INPUT:

Sampling frequencies: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz

All sampling frequencies must lie within ±100 ppm of the nominal sampling frequency

Maximum input word-length: 24 Bits

Channel Status Data: Input accepts professional or consumer format

Connector: XLR female, 110 (termination switchable on/off)

AES/EBU OUTPUT:

Sampling frequencies: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz

Output word-length: 16 Bits, 24 Bits

Connector: Two times XLR male, 110

Professional Channel Status Data format

Single Wire format for sampling frequencies between 44.1 kHz and 192 kHz

Double Wire format for sampling frequencies of 88.2 kHz or higher (switch selectable)

S/PDIF OUTPUT:

Sampling frequencies: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz

Output word-length: 16 Bits, 24 Bits

Connector: One RCA, 75

Professional Channel Status Data format

WORD-SYNC I/O:

Sampling frequencies: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz

Connector: BNC, 75 (termination on input switchable on/off)

TTL level

FIREWIRE:

A Firewire I/O kit is available as an option

MEASUREMENTS:

All measurements are taken at the least sensitive setting of the input attenuators, i.e. +26 dBu sensitivity for line and +6 dBu sensitivity for mic inputs. (Equals the sensitivity for a 0 dBFS output level).

Low Cut Frequency Response:

1st order high-pass, 3 dB point at 40 Hz

Frequency Response:

Fs = 44.1 kHz, 20 Hz...20 kHz: ±0.3 dB

Fs = 48 kHz, 20 Hz...20 kHz: ±0.3 dB

Fs = 88.2 kHz, 20 Hz...30 kHz: ±0.3 dB

Fs = 96 kHz, 20 Hz...30 kHz: ±0.3 dB

Fs = 176.4 kHz, 20 Hz...40 kHz: ±0.3 dB

Fs = 192 kHz, 20 Hz...40 kHz: ±0.3 dB

THD+N at 1 kHz:

Less than 103 dBFS at 3 dBFS output level, unweighted

SNR at 40 dBFS input:

Higher than 110 dB unweighted

Crosstalk:

Less than 120 dB, 0 Hz...20 kHz

CMRR:

Higher than 90dB at 1 kHz

Higher than 80dB at 20 kHz

Higher than 60dB at 20 Hz

Interchannel Phase Tracking:

Better than ±0.3, 20 Hz...20 kHz

Latency:

Fs = 44.1 kHz: 2.6 ms

Fs = 48 kHz: 2.49 ms

Fs = 88.2 kHz: 1.8 ms

Fs = 96 kHz: 1.75 ms

Fs = 176.4 kHz: 1.4 ms

Fs = 192 kHz: 1.38 ms

PARAMETER TABLES:

Analogue Gain Line Input (dB):

26.0, 25.0, 24.0, 23.0, etc. in 1dB steps up to +16.0

Example: with a gain setting of 26.0, a +26 dBu input signal generates a 0 dBFS output signal.

Analogue Gain Mic Input (dB):

6.0, 5.0, 4.0, etc. in 1 dB steps up to +54.0