Model 381 On-Air Beltpack User Guide Issue 2, March 2020 This User Guide is applicable for serial numbers M381-00151 and later with application firmware 1.1 and later and STcontroller application version 2.07.00 and later. Copyright © 2020 by Studio Technologies, Inc., all rights reserved www.studio-tech.
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MODEL 381 ON-AIR BELTPACK Table of Contents Revision History ........................................................... 4 Introduction ................................................................... 5 Getting Started ............................................................. 8 Operation ...................................................................... 14 Technical Notes ............................................................ 18 Specifications ..............................................
MODEL 381 ON-AIR BELTPACK Revision History Issue 2, March 2020: • Revised nomenclature associated with operation of talkback button. Issue 1, January 2019: • Initial release. Issue 2, March 2020 Page 4 Model 381 User Guide Studio Technologies, Inc.
MODEL 381 ON-AIR BELTPACK Introduction The Model 381 On-Air Beltpack offers a unique combination of audio resources to directly support a complete broadcast “stand-up” on-air position. Using Dante® audio-over-Ethernet technology, the unit provides main and talkback output channels, talent cue (IFB) input, and sidetone capabilities, as well as essential user controls in a compact, portable package.
MODEL 381 ON-AIR BELTPACK Setup and Operation Set up and operation of the Model 381 is simple. An etherCON® RJ45 jack is used to interconnect with a standard twisted-pair Ethernet port associated with a PoE-enabled network switch. This connection provides both power and bidirectional digital audio. A broadcast headset or handheld (“stick”) microphone can be directly connected to the unit’s 3-pin XLR microphone input connector. This input is compatible with dynamic or condenser microphones.
MODEL 381 ON-AIR BELTPACK is preserved while minimizing the chance of signal overload. A configuration choice allows selection of the signal source for the Dante main output channel. The choices are either the output of the microphone preamp or the output of the compressor circuit. These choices are referred to as “pre-compressor” or “post-compressor.” The ADC section utilizes a high-performance integrated circuit that supports sampling rates of 44.1, 48, 88.2, and 96 kHz with a bit depth of up to 24.
MODEL 381 ON-AIR BELTPACK Future Capabilities and Firmware Updating The Model 381 was designed so that its capabilities and performance can be enhanced in the future. A USB connector, located on the unit’s main circuit board (underneath the unit’s cover), allows the application firmware (embedded software) to be updated using a USB flash drive. The Model 381 uses Audinate’s Ultimo™ integrated circuit to implement the Dante interface.
MODEL 381 ON-AIR BELTPACK or P48 phantom powered microphones. A microphone should be connected such that its common is on connector pin 1, its signal high (+) is on connector pin 2, and its sign low (–) is on connector pin 3. An STcontroller configuration setting allows the P48 microphone power sources to be enabled or disabled as desired. Details on configuring the unit will be described later in this guide.
MODEL 381 ON-AIR BELTPACK also need to be subscribed (routed) with the desired Dante transmitter (Tx) channels. These two audio signals will provide a Model 381 user with their headphone cue signals. The Model 381 has a default Dante device name of ST-M381- and a unique suffix. The suffix identifies the specific Model 381 that is being configured. The suffix’s actual alpha and/or numeric characters relate to the MAC address of the unit’s Ultimo integrated circuit.
MODEL 381 ON-AIR BELTPACK Microphone Input – Gain Choices are 36 dB, 42 dB, 48 dB, 54 dB, and 60 dB. be routed to both the left and right headphone output channels. The gain of the Model 381’s microphone preamplifier can be selected from among five choices. The compressor active LED, orange in color and visible on the bottom of the Model 381’s enclosure adjacent to the microphone input connector, can act as a guide when setting the preamp gain.
MODEL 381 ON-AIR BELTPACK The control on the right, labeled B, will allow adjustment of input channel 2. Note that in this mode the level of the sidetone audio signal will be determined by the configuration of the Fixed Sidetone Level setting. Ch 1 & 2 Level / Balance This mode is provided primarily for use in “stereo” applications such as live music events or radio broadcasts.
MODEL 381 ON-AIR BELTPACK Talkback Active In this mode the sidetone function will be active whenever the talkback function is active and the audio signal is present on the Dante talkback output channel. Whenever the main output function is active sidetone audio will not be enabled. Always Active In this mode the sidetone function will always be active and sidetone audio will be continuously routed to the headphone output.
MODEL 381 ON-AIR BELTPACK can be appropriate when the most accurate representation of the microphone input signal is desired. This would allow maximum “downstream” control of a signal that is to be used for “on-air” or other primary purposes. Any processing of audio coming from the main output channel would need to be performed in equipment that’s “post” (after) the Model 381 in the audio chain. The downside of selecting pre-compressor is an increased risk of signal overload.
MODEL 381 ON-AIR BELTPACK pushbutton switch will flash on and off approximately eight times. (Of course, the Identify command will not change the on/off status of the button.) In addition, the SYS and SYNC status LEDs, located directly below the etherCON RJ45 connector on the bottom panel, will slowly flash green. After a few seconds this LED identification pattern will cease and normal Model 381 talkback button LED and Dante status LED operation will resume.
MODEL 381 ON-AIR BELTPACK knobs to be in the “out” position when the level needs to be adjusted and in the “in” position when protection from an unwanted change is desired. Analog audio signals do not pass directly through the two controls. The position of the controls is recognized by the Model 381’s processor which then adjusts the actual signal level within the digital domain.
MODEL 381 ON-AIR BELTPACK • In the Ch 1 & 2 Level / Balance mode the control on the left, labeled A, adjusts the level of both the Ch 1 and Ch 2 input audio signals as they are sent to both the left and right headphone output channels. The control on the right, labeled B, will adjust the level balance of audio input Ch 1 and audio input channel 2. The level of the sidetone audio will follow the Fixed Sidetone Level configuration and will be sent to both the left and right headphone output channels.
MODEL 381 ON-AIR BELTPACK Depending on the configuration of the Headphone Output – Controls selection in STcontroller, the level of the sidetone audio will be determined either by the selected value in the Fixed Sidetone Level configuration or by adjustment of the right control, labeled B, that is located on the top panel. Typically, providing a precise sidetone level is not important and most users will not be concerned about setting it to a specific value.
MODEL 381 ON-AIR BELTPACK An exception does arise when trying to directly interconnect two Dante-enabled devices that use Ultimo integrated circuits to implement Dante. The Model 381 uses the Ultimo “chip” and, as such, a direct oneto-one interconnection to another Ultimobased product is not supported. An Ethernet switch linking the two units is required to successfully interconnect two Ultimo-based devices.
MODEL 381 ON-AIR BELTPACK button is released. Once the talkback button is released normal operation will then take place. As an example of what would be a typical firmware display, if the talkback button’s LED “flashes” green once followed by the LED “flashing” orange once it would indicate that application firmware version 1.1 is present in the Model 381. A selection in the STcontroller software application allows the Model 381’s application firmware version to be identified.
MODEL 381 ON-AIR BELTPACK 5. After a few seconds the Model 381 will run a “boot loader” program that will automatically load the new application firmware file (m381.bin). This loading process will take only a few seconds. During this time period the talkback button LED will flash slowly in alternate colors. Once the entire loading process is over, taking approximately 10 seconds, the Model 381 will restart using the newly-loaded application firmware. 6.
MODEL 381 ON-AIR BELTPACK Specifications Power Source: Power-over-Ethernet (PoE): class 2 (low power, ≤6.49 watts) Network Audio Technology: Type: Dante audio-over-Ethernet AES67-2013 Support: yes Dante Domain Manager (DDM) Support: yes Bit Depth: up to 24 Sample Rate: 44.1,48, 88.
MODEL 381 ON-AIR BELTPACK Appendix A STcontroller default Model 381 configuration values: Microphone Input – P48 Phantom Power: Off Microphone Input – Gain: 42 dB Headphone Output – Routing: Dual-Channel Stereo Headphone Output – Controls (A/B): Ch 1 Level/Ch 2 level Headphone Output – Sidetone Mode: Main Active Headphone Output – Fixed Sidetone Level: Off Talkback Button – Operation: Momentary System Mode – Main Output Source: Post-Compressor Model 381 User Guide Studio Technologies, Inc.