Analog to Digital Converter

The RDL HR-ADC1 is a broadcast-quality analog-to-digital audio converter designed for stereo audio systems requiring flexible digital formats, selectable conversion settings, external synchronization, and detailed front-panel monitoring. It accepts balanced and unbalanced stereo analog audio and provides AES/EBU, coaxial S/PDIF, and AES-3ID outputs. Operation is selectable up to 24-bit resolution and a 192 kHz sample rate.

Ideal Use Cases

The HR-ADC1 fits audio paths where analog stereo sources must connect to digital equipment using professional or coaxial digital audio formats. Its input, output, and synchronization options accommodate several system requirements without changing converters.

• Broadcast-quality conversion of balanced or unbalanced stereo analog audio.
• Systems requiring AES/EBU, coaxial S/PDIF, or AES-3ID digital audio connections.
• Applications that must operate at selectable sample rates and 16-, 20-, or 24-bit resolution.
• Audio systems that need synchronization from an external AES/EBU, S/PDIF, or AES-3ID source.

Why Choose This Model

Six sample rates are supported: 44.1, 48, 88.2, 96, 176.4, and 192 kHz. Resolution is front-panel selectable at 16, 20, or 24 bits. The converter can use an internally generated sample rate and bit depth or operate with external synchronization enabled from the front panel.

Separate left and right front-panel controls provide adjustable audio input gain trim. Metering can use peak or average ballistics with a selectable 0 dB reference. Peak metering also offers selectable hold and peak-store modes. Dedicated indicators display power, external-sync lock, sample rate, bit depth, audio levels, and peak levels.

Installation and Integration

Balanced input connections include 30 kΩ XLR and terminal-block interfaces, while two 30 kΩ RCA jacks support unbalanced audio. Nominal balanced input level is +4 dBu, with an adjustment range from +2 to +26 dBu. Nominal unbalanced level is -10 dBV, adjustable from -11 to +11 dBV for 0 dBFS.

External synchronization inputs comprise a transformer-isolated 110 Ω AES/EBU XLR, a 75 Ω S/PDIF RCA jack, and a 75 Ω AES-3ID BNC connection. Outputs include transformer-isolated 110 Ω AES/EBU on XLR, 75 Ω S/PDIF on RCA, and selectable 75 Ω AES-3ID on BNC.

The unit measures 1.7 inches high, 8.6 inches long, and 4.59 inches deep. It requires ground-referenced 24 Vdc at 300 mA. The recommended PS-24AS power supply for the USA or PS-24AX for international use is not included.

Performance Highlights

Specified frequency response is 10 Hz to 20 kHz within ±0.125 dB and 20 Hz to 20 kHz within ±0.05 dB. At 24-bit resolution, unweighted dynamic range is greater than 114 dB. THD+N is less than -105 dBFS, or 0.0006%, from 20 Hz to 20 kHz using the internal sample rate. Residual noise is less than -135 dB from 10 Hz to 20 kHz. Crosstalk is less than -115 dB at 50 to 60 Hz and less than -105 dB at 15 kHz.

What Makes It Different

The HR-ADC1 brings balanced and unbalanced analog connectivity, three digital output standards, three external synchronization formats, selectable conversion parameters, and extensive metering into one focused converter. Four programmable feature menus cover metering ballistics, the meter’s 0 dB reference, peak hold or store behavior, and display intensity.

Its 49 indicators include power and external-sync lock status, six sample-rate indicators, three bit-depth indicators, 26 audio-metering indicators, and 12 peak-metering indicators. A transformer-isolated AES/EBU output and transformer-isolated AES/EBU synchronization input are included in the specified connection set.

Final Assessment

For systems requiring stereo analog-to-digital audio conversion across AES/EBU, coaxial S/PDIF, and AES-3ID formats, the RDL HR-ADC1 provides clearly defined control over sample rate, resolution, input level, synchronization, and metering. Its specifications cover conversion through 24 bits and 192 kHz, while the front-panel controls and indicators expose the settings needed during integration and operation.