HeadAmp 4 Pro Five Channel Headphone Amp with Listen and Talkback Project Series User’s Manual
IMPORTANT SAFETY INSTRUCTIONS – READ FIRST This symbol, wherever it appears, alerts you to the presence of uninsulated dangerous voltage inside the enclosure. Voltage that may be sufficient to constitute a risk of shock. This symbol, wherever it appears, alerts you to important operating and maintenance instructions in the accompanying literature. Please read manual. Read instructions: Retain these safety and operating instructions for future reference. Heed all warnings printed here and on the equipment.
TABLE OF CONTENTS IMPORTANT SAFETY INSTRUCTIONS – READ FIRST ................................. I INTRODUCTION ............................................................................................... 1 OVERVIEW ....................................................................................................... 2 SETTING UP ..................................................................................................... 2 UNPACKING ................................................................
INTRODUCTION Thank you for purchasing Applied Research and Technology’s HeadAmp 4 Pro. After getting familiar with the HeadAmp 4 Pro, you’ll realize what a great investment you’ve just made. The HeadAmp 4 Pro is a unique product. It contains five high quality headphone amps and adds talkback to any one or all of the outputs as well as the ability to monitor or mix any input to a special output.
OVERVIEW The HeadAmp 4 Pro is a multi-purpose tool for audio engineering and recording. Enclosed in a tabletop chassis are five headphone amps with talkback capability. Up to five of the inputs can be monitored at once. The HeadAmp 4 Pro is designed to work seamlessly with any classroom, recording, sound-reinforcement, or electronic instrument setup. The HeadAmp 4 Pro maintains exceptional signal integrity and extremely low noise. Each 1/4" input accepts line level signals that can be adjusted for level.
The external mic jack is designed for low impedance balanced mics. This input provides phantom power for mic that need it and can be safely used with mics that do not require it. We recommend using only high quality cables equipped with the appropriate connectors. Powering up When power is applied, the Power switch will illuminate indicating the unit is on. It is important to remember to turn the HeadAmp 4 Pro output controls to minimum before connecting to any of the outputs.
FRONT PANEL CONTROLS & INDICATORS Figure 1 - Front view External mic jack The external mic jack is a balanced mic level input. This input is intended for use with a dynamic or phantom powered microphone. It will not accept line level inputs without clipping. The external mic input provides +48V on pins 2 and 3 for condenser mics while safely supporting the use of dynamic mics. Power switch The Power switch turns the entire unit on or off. The switch cap doubles as a power indicator.
Output controls Each output control provides level adjustment from 10dB of gain to completely muted for each output channel. The audio used for Listen is selected before this control so you can adjust the headphone levels without worrying about changing the listen buss levels.
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Talk switches The four Talk switches are used to direct the talkback mic to individual channels. These switches are momentary and slightly mute their respective input signal when passing through the talkback audio. Talk All switch Depressing the Talk All switch is the same as depressing ALL of the Talk switches plus it enables talkback into the Listen output. The Listen output's normal audio signal is completely muted while the talkback signal is passed on when this switch is depressed.
REAR PANEL FUNCTIONS Figure 3 - Rear view Power Connect the power supply provided with your unit to this jack. The HeadAmp 4 Pro is designed for use with a 9V AC power supply rated at 1000mA. Using a DC power supply will not work. Using a power supply of greater voltage may damage your unit. Using a power supply of greater current (9VAC, but >1000mA) will work OK. When power is applied to the unit, the Power switch will be lit. If this switch is NOT lit, check the power source and connections.
Main inputs The Main Inputs are stereo (TRS) or mono (TS) input jacks that accept line or headphone level signals. The Main Inputs are the audio source for all of the outputs that do NOT have audio connected to the Aux Input jacks. Use the Left (stereo) input if you have a stereo TRS cable. Use both the Left and Right input if you have mono (TS) cables for each input.
Headphone outputs The Out jacks can drive headphones as well as line level inputs. The Out controls on the front of the unit adjust the volume of all of the audio present on the corresponding output. Each output contains either the Main input audio or the Aux input signal for that channel if the jack is used. If the Talkback Footswitch or the Talk All switch are active, the Main or Aux audio are muted (by about 30 dB) and talkback audio is present.
APPLICATIONS Recording The HeadAmp 4 Pro is at home in the modern studio. Since most current setups have little in the way of analog processing like a mixer, The HeadAmp 4 Pro fills in the gap. The talkback feature allows everyone to keep the headphones on and still communicate. The main mix is connected to the main input and is supplied to all channels. Individual headphone mixes are sent to the Aux inputs, which override the main input.
Instruction Individual instruments are patched in through the Aux inputs. They can then be monitored and you can provide individual feedback using the talkback function available on each output. Using the talk all function, you can address the entire group. Using multiple HeadAmp 4 Pro's, you can have each student use one unit as a mixer with up to four inputs. The student uses the Listen output for his headphones. Each student unit's Main Input is connected to the teacher's unit.
WARRANTY INFORMATION: Limited Warranty (USA only): Applied Research and Technology will provide warranty and service for this unit in accordance with the following warrants: Applied Research and Technology, (A R T) warrants to the original purchaser that this product and the components thereof will be free from defects in workmanship and materials for a period of three years from the date of purchase.
SERVICE: The following information is provided in the unlikely event that your unit requires service. 1) Be sure that the unit is the cause of the problem. Check to make sure the unit has power, all cables are connected correctly, and the cables themselves are in working condition. You may want to consult with your dealer for assistance in troubleshooting or testing your particular configuration. 2) If you believe that the ART unit is at fault, go to www.artproaudio.com.
SPECIFICATIONS: Input Connections: ........................................................................................1/4" stereo TRS (except Main Right input which is TS only) Input Impedance: 1/4" ....................................................................................>10K Ohms XLR input........................................................................................................2K Ohm Maximum Input Level: 1/4".....................................................................
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