User Manual
Model 1726 Headphone Demonstrator
Introduction
The Model 1726 amplifier is designed to demonstrate headphones featuring analog or digital Toslink® connections. It supports PCM-2 and Dolby® 5.1 digital signals. The 1726 is compatible with any audio or audio-video player. With an RS-232 compatible player and custom programming, it can trigger specific tracks for each headphone output. Contact your Account Manager for details regarding player control.
Features
Choose desired features and select using the DIP switches as shown. Cycle power after making changes to the DIP switches.
SilenTouch™
Prevents switching noise when activating tracks.
Feature Switches: [Diagram showing DIP switches, e.g., Switch 1: OFF, Switch 2: ON, Switch 3: OFF, Switch 4: ON]
Timeout Dial
All outputs deselect after a period of inactivity, defined by the timeout interval. The timeout interval is set by the Timeout dial, in increments of 15 seconds. If the timeout switch is set to 0, the demonstration does not time out. When a customer makes a selection, the timer resets.
| Interval | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|
| Seconds | 15 | 30 | 45 | 60 | 75 | 90 | 105 | 120 | 135 | Never |
Analog Gain Switch
The gain can be set to Low, Mid, or High, depending on the Sound Pressure Level (SPL) desired for analog headphones on display. Digital audio outputs are not affected. See page 4 for setup instructions.
[Image of Analog Gain Switch]
Connections
Digital Audio Inputs/Outputs
Connect an optical cable from the media player's output to the 1726 optical input. Connect an optical cable from each of the headphone output connectors to the corresponding headphone's audio port. Connect only one audio cable to each headphone system.
Analog Audio Inputs/Outputs
Connect an analog stereo cable from the media player's output to the 1726 analog 3.5 mm input. Connect an analog 3.5 mm cable from each of the headphone output connectors to the corresponding headphone's audio port.
RS-232 Port
The 1726 can be programmed to send RS-232 commands to a compatible player. Use a standard serial cable (male to female) for RS-232 communication. Contact your Audio Authority Account Manager for details.
| GND | RX | TX | Transfer Rate | Data Bits | Parity | Flow Control | Character type | Connector | Electrical Rating | |
|---|---|---|---|---|---|---|---|---|---|---|
| Shell, Ground | Pin 5, Ground | Pin 3, Rx | Pin 2, Tx | 9600 bps | 8 | None | None or Off | ASCII | DB-9 | Pins 2 and 3, ±15 VDC |
SD Status LED
See audioauthority.com/product_details/1726 for more information.
Power Input
Connect the included 12V power supply to the Power Input port. Connect a 5.5 mm jumper cable from the 12V Power Bus connection to other 1726 units if desired.
Media Player Guidelines
To maximize the performance of the 1726 amplifier, it is recommended to use the highest quality music files possible. Uncompressed FLAC or WAV files are ideal, but high bit-rate MP3 files may also be suitable for demonstration. If headphones to be demonstrated have both analog and digital inputs, the media player must provide both analog and digital signals simultaneously. The Audio Authority Model 1703 music player is recommended for this purpose.
Player Control Option
Certain audio or video devices are compatible with the 1726 player control feature. Any source device can provide audio, but with a compatible player and custom programming, the 1726 can trigger a specific track for each selected headphone output. The player must have its own dedicated volume controls. Contact your Account Manager for details.
Installation
- Read these instructions and set the Feature switches for the desired demo behavior (refer to page 3). Cycle power to the 1726 after making any changes to the Feature switches.
- Attach the 1726 to a surface using the provided screws.
- Connect push-buttons for headphone selection. Push buttons can be 4-wire or 2-wire momentary switches and can be illuminated (2-5 volt LED).
- Connect an RS-232 cable to a media player if serial control is utilized.
- Connect the power supply to AC power, then to the 1726 power port.
- Connect audio input(s) from the media player to the 1726 amplifier.
- Connect audio output to headphones.
- Adjust the analog gain switch using the guidelines provided below.
Analog Gain Switch Settings
The setting for the Analog Gain Switch depends on the headphones being displayed. The interaction between headphone impedance (Ohms) and sensitivity (dB) influences the Sound Pressure Level (SPL) when combined with the Model 1726's output power. Set the media player output volume, using dynamic material, to the maximum level before distortion occurs. Reference each of the headphones being displayed and adjust the Analog Gain Switch to achieve a suitable listening level. If the headphones on display have a wide range of sensitivity and impedance, consider grouping them into two or more sets, each with a different gain setting.
Operation
To begin a demonstration, select each pair of headphones from the headphone display and press the product select button. The demo concludes after the timeout interval, measured from the last product selection. All outputs are muted after each demo.
