Product Overview

DH20/22

Comrex’s Digital Hybrid series are high quality single- and dual-line telephone interfaces. Designed to interconnect a standard telephone line and your audio equipment, the DH Series enables users to send and receive audio from a connected telephone line. When the very best audio quality is required for talk shows, news feeds, production, recording studios, or internet applications, these digital hybrids are ideal.

With DSP technology, the DH20 and DH22 deliver the deepest and most stable hybrid null, ensuring maximum isolation between the send and caller audio. This means no echo or “bottom of the barrel” sound.

Additionally, the DH20 and DH22 come with selectable automatic gain control (AGC) and caller ducking. With AGC, each call will be delivered to the equipment at the same level. Caller ducking reduced the caller’s audio level when the announcer speaks, providing a more “controlled” environment. Additionally, we’ve added a speaker amplifier, so you can connect a speaker directly to the unit and monitor callers without headphones.

DH30

The DH30 digital hybrid provides a high quality interface between a standard telephone line and your audio equipment. Designed with both AES/EBU and analog inputs and outputs, the DH30 works with the latest digital and analog consoles. To ensure quality sound in studios that have open speakers and microphones, the DH30 is equipped with an acoustic echo cancellation feature.

The DH30’s digital signal processing (DSP) has multiple adjustable parameters to provide you with the best send and caller audio signals. New audio processing features such as the compressor and downward expander functions ensure that the best audio reaches your audience. All audio processing features are programmable via the front panel controls. For the deepest, most reliable hybrid null, and the best quality caller audio for your application, the DH30 is the answer.

Easy to use and install, the DH30 has simple front panel controls and remote control capability. These controls put the On, Off, Rec, and Cue functions right at your fingertips. The DH30 also includes a 2W monitor amp with volume controls right on the front panel. The Rec function sends a start/stop signal to your external recording device. The Cue function allows you to control which audio signal should be sent to the caller, allowing you to switch from the Send input to the Cue input at the touch of a button.

Features

DH20/22

  • DSP digital technology ensures the very best audio quality and the deepest, most reliable hybrid null
  • Built-in speaker amplifier
  • Selectable AGC ensures every caller is at the same audio level
  • Selectable caller ducking
  • Selectable auto-answer/auto-disconnect compatible with most telephone central offices including loop current interruption and busy/reorder tones
  • Remote control and status

DH30

  • Record and Cue functions
  • 24-bit digital signal processing (DSP)
  • Remote control via contact closures or RS-232
  • Adjustable caller control (ducking), three-band equalizer, compressor and expander.
  • Selectable auto mix-minus, auto answer and disconnect, and acoustic echo cancellation
  • AES/EBU digital or analog audio input and output

Specifications

DH20/22

  • Mic or line input
  • Automatically accepts all worldwide voltages
  • Worldwide compliant, including FCC, CSA, CE and CTR21
  • Dry line capability (U.S. version only)
  • Balanced audio in and out
Connections
  • Caller Output: XLR male, 0dBu nominal, adjustable, balanced, 50 Ohm impedance
  • Aux Output: XLR male, 0dBu nominal, adjustable, balanced, 50 Ohm impedance
  • Telco Line: RJ-11 connector, POTS line or analog extension from a PBX or dry line (no DC offset voltage)
  • Telco Set: RJ-11 connector
  • Remote: DB-25 Female
  • Remote Send Input: 0dBu nominal, adjustable, unbalanced, 20k Ohm impedance
  • Remote Caller and Aux Output: 0dBu nominal, adjustable, unbalanced, 50 Ohm impedance
  • Control Inputs: Remotely activate any of the following functions with a switch closure to ground: On, Off, and Monitor Mute
  • Status Outputs: Remotely check the status of the hybrid using the On and Off status outputs. Status outputs are open collector outputs rated at 30VDC and 40mA maximum
  • Monitor Output: 1/4″ stereo jack: Tip=+phase, Ring=ground, Sleeve=ground, 1W output into an 8 Ohm load
  • Send Input: XLR female, Mic/Line selectable, -55/0 dBu nominal, adjustable, balanced, bridging, 20k Ohm impedance
Telephone Transmit
  • Nominal send input of 0 dBu referenced to -15 dBu onto the telephone line
  • Frequency Response: 250 Hz to 3.5 kHz, ±1dB
  • Distortion: <0.1%
Telephone Receive
  • Nominal telephone line level of -15 dBu referenced to caller output of 0 dBu
  • Frequency Response: 250 Hz to 3.5 kHz, ±1 dB
  • Distortion: <0.1%
Mix-Minus
  • Caller-to-Send separation: 50 dB nominal
  • Tail time: 32 milliseconds
Controls
  • On/Off Buttons
  • Volume Up/Down Buttons
Status LEDs
  • On Status, Off Status
  • Send Audio Presence
  • Caller Audio Presence
Adjustments
  • Send Input Level
  • Caller Output Level
  • Auxiliary Input Level
  • Auxiliary Output Level
  • Burst Adapt Select
  • Mic/Line Select
  • Caller Boost Select
  • Momentary/Latching Select
  • Auto Answer/Disconnect Select
  • Caller Control Select (0, 6, 12, or 18 dB)
  • AGC Select
  • Auto Mix-Minus Select
  • Aux Mix Select
Null
  • Send-to-Caller separation: 55dB nominal
  • Tail time: 32 milliseconds
Power & Physical
  • Power: IEC Type, Auto Adjusting 100-240VAC, 2A, 50/60Hz, 30W
  • Size: 17.125″ L x 10.125″ D x 1.75″ H (43.6 cm x 25.7 cm x 4.44 cm)
  • Weight: 6.35 lbs (2.88 kg)
  • Operating Temperature: 32-100° F (0-38° C)
  • Humidity: 0-80 percent

DH20-back_MainImage DH22-back_MainImage

 

DH30

  • Remote controllable presets
  • Password protected
  • Selectable auto mix-minus
  • Selectable acoustic echo cancellation
  • Selectable auto answer and disconnect
  • Integrated monitor amp with front-panel volume control
  • Adjustable caller control (ducking)
  • Adjustable three-band equalizer
  • Adjustable compressor and expander
  • Bass boost
  • Microphone send and cue preamps
  • Automatically accepts all worldwide voltages
  • Three selectable presets for customized audio
  • Worldwide compliant including FCC, CSA, CE, CTR 21
Connections
  • Cue In: XLR Female, Mic/Line selectable, -55 or 0 dBu nominal, adjustable, balanced bridging, 20k Ohm impedance, selectable 12VDC phantom power
  • Caller Output: XLR male 0dBu nominal, adjustable, balanced, 50 Ohm impedance
  • Aux Output: XLR male 0dBu nominal, adjustable, balanced, 50 Ohm impedance
  • Telco Line: RJ-11 connector – POTS line or analog extension from a PBX or dry line (no DC offset voltage), A-Lead supervision provided
  • Telco Set: RJ-11 connector, A-Lead supervision provided
  • Remote: DB-25 Female
  • Remote Send Input: 0dBu nominal, adjustable, unbalanced, 20k Ohm impedance
  • Remote Caller and Aux Output: 0dBu nominal, adjustable unbalanced, 50 Ohm impedance
  • Control Inputs: Remotely activate any of the following functions with a simple switch closure to ground: On, Off, Cue, and Rec along with preset selection controls 1,2, and 3 or with Send, Caller, and Monitor Mute controls
  • Status Outputs: Remotely check the status of the hybrid using the On and Off status outputs. Status outputs are open collector outputs rated at 30VDC and 40mA maximum
  • Monitor Output: 1/4″ stereo jack Tip=+phase, Ring=ground, Sleeve=ground, 1W output into an 8 Ohm load
  • Send Input: XLR female Mic/Line selectable, -55/0 dBu nominal, adjustable, balanced, bridging, 20k Ohm impedance
  • AES/EBU In: XLR, Pin 1=ground, Pin 2=+phase, Pin 3=-phase; 32, 44.1, or 48 kHz sample rate
  • AES/EBU Out: XLR, Pin 1=ground, Pin 2=+phase, Pin 3=-phase; 32, 44.1, or 48 kHz sample rate
  • RS-232: DB9 Female Connector, 9,600 baud rate, used for status and control via a PC or other RS-232 controller
  • Record Control: DB9 Female, Start, stop, and enable outputs are open collector outputs rated at 40VDC and 50mA maximum
Controls
  • LCD programming display, ENTER/ESC/st programming buttons, Monitor volume control, Send-level LED bar meter, Caller-level LED bar meter, Record, cue, Hybrid On/Off, Buttons with status LEDs
Telephone Transmit
  • All measurements referenced at -15 dBm level on the phone line
  • Frequency response: 250 Hz to 3.5 kHz, ±1 dB
  • SNR: >70 dB
  • Distortion: <0.15%
Telephone Receive
  • All measurements referenced at -15 dBm level on the phone line with caller processing options bypassed
  • Frequency response: 250 Hz to 3.5 kHz, ±1 dB
  • SNR: >70 dB
  • Distortion: <0.1%
Echo Cancellation/Mix-Minus
  • Tail time: 120 milliseconds
  • Null: 50 dB
Telco Cancellation
  • Tail time: 32 milliseconds
  • Null: 55 dB
Null
  • Send-to-Caller separation: 55 dB nominal
  • Tail time: 32 milliseconds
Power & Physical
  • Power: IEC Type, Auto Adjusting 100-240VAC, 2A, 50/60 Hz, 30W
  • Dimensions: 17.125″ L x 10.125″ D x 1.75″ H (43.5 cm x 25.7 cm x 4.44 cm
  • Weight: 6.7 lbs (3.04 kg)
  • Operating Temperature: 32-100° F (0-38° C)
  • Operating Humidity: 0-80 percent

DH30-back_MainImage

Parts

Power Cord (EAC Socket)

$8

More Info

Product Support

Need help with your product? Click below to find troubleshooting tips, new software, and technical support.

Get Product Support

Find a Dealer

Looking to make a purchase? Click below to find an authorized Comrex dealer in your area.

Find an Authorized Dealer

Want to Learn more?

Contact us