User manual ART HEADAMP 6

[. . . ] Moisture: To reduce the risk of fire or electrical shock do not expose the unit to rain, moisture or use in damp or wet conditions. Do not place a container of liquid on it, which may spill into any openings. Heat: Do not locate the unit in a place close to excessive heat or direct sunlight, as this could be a fire hazard. Locate the unit away from any equipment, which produces heat such as: power supplies, power amplifiers and heaters. [. . . ] Independent output level controls on each channel personalize monitoring levels. Input options include XLR and 1/4-inch TRS balanced inputs with matching "Thru" jacks for bridging multiple units. An additional front panel stereo 1/4-inch TRS Direct In jack for quick patch override of the rear panel inputs is included for quick insertion of any stereo source. Eight-segment precision LED level metering on the main bus and four-segment indicators on each output channel provide visual feedback of the signal level at all key points. INSTALLATION The HeadAmp6 may be used in a wide variety of applications and environments. Its rack-mountable steel and aluminum enclosure is both attractive and designed for continuous professional use. However, for better performance and greater reliability we recommend that you not place the unit on top of power amps or other sources of extreme heat, or strong magnetic fields. AC Power Hookup The HeadAmp6 has an internal power supply. Only connect the unit to mains power of the type marked on the rear panel. The power source must provide a good ground connection, and the ground pin on the mains plug should never be defeated. Analog Audio Connections Audio connections to and from the HeadAmp6 are: Rear Balanced Inputs and Outputs: [XLR] [1/4-inch] Front Stereo Aux 1/4-inch Inputs: Front Direct 1/4-inch Input: Front and Rear Stereo Headphone 1/4-inch Outputs: · · · · · · · · · · · · Pin 2 = Pos(+), Pin 3 = Neg(-), Pin 1 = Ground Tip = Pos(+), Ring = Neg(-), Sleeve = Ground Tip = Left, Ring = Right, Sleeve = Ground Tip = Left, Ring = Right, Sleeve = Ground Tip = Left, Ring = Right, Sleeve = Ground Six Independent High-Power Headphone Amplifier Channels Dual Function Balance/Mix Control per Channel Front Panel Stereo Aux Input for each Channel Multiple Monitoring Settings per Channel Individual Output Level Control per Channel Precision Four Segment LED Metering Per Channel Master Volume Control w/ Eight Segment LED Metering Front Panel Direct In Jack One Front and Two Rear Mounted Headphone Jacks per Channel Connects and Drives up to 18 Headphones Simultaneously XLR and 1/4" Main Inputs and Outputs Parallel Main Outputs for Multiple Unit Use 4 CONTROLS and JACKS Front Panel FIGURE 1 - Master Volume, Direct In, and Channel One Direct In Jack The 1/4-inch TRS (Tip, Ring, Sleeve) jack on the front panel provides a stereo unbalanced input which, when used, will override the rear panel balanced inputs. This input is useful for when you want to temporarily insert a different main input signal from what is connected to the rear inputs, or simply make an unbalanced TRS style connection to another headphone output source. Master Volume Control This control adjusts the level of the main signal bus. The eight-segment LED level meter located just to the left of the MASTER VOLUME control displays the audio level on the main signal bus. Mute L, Mute R, and Mono Switches These switches set the stereo headphone outputs to one of three operating modes. (This affects only the headphone outputs and occurs post (after) the balance/mix, and level control sections. ) 1) All Switches Out = Stereo 2) Mute L In & Mute R Out & Mono In = Right Channel Only in Mono 3) Mute R In & Mute L Out & Mono In = Left Channel Only in Mono Stereo Aux In Jack These stereo TRS jacks provide a means of inserting a direct stereo signal into an individual headphone channel. When a plug is inserted into an AUX INPUT jack the BALANCE control for that particular channel changes function to become a mix control adjusting the mix between the signal coming into that channels stereo AUX IN and the main signal bus. Out Jack This stereo TRS 1/4-inch jack provides a connection for each of six output channels to stereo headphones or to additional headphone distribution amplifiers. Two identical output jacks are provided on the rear panel for each channel as well. 5 Balance Control This control provides one of two functions depending on whether there is a plug inserted into the stereo AUX IN for a particular channel. With no plug inserted into the AUX IN jack, the control will vary the Left / Right balance of the main signal bus feed to the channel. With a plug inserted, the control changes function to vary the mix between the stereo signals coming from the main signal bus and the stereo signals coming from the AUX IN for that respective channel. Most modern headphones are medium to high impedance and require only milliwatts to achieve full acoustic output so this should rarely be a problem. If it is a problem simply lower the level or lower the total count of headphones on a particular channel in order to increase the total load impedance as seen by the channel output. There is no direct relationship between headphone load impedance and SPL output. The relevant specification that determines acoustic output is the sensitivity spec of the headphone, i. e. how much SPL it will put out for a given level of input signal, usually rated at 1 mW. Sensitivity is determined by the overall design and construction of the transducer. Typically the power required is about 1/1000th of the equivalent amplifier power required to drive a speaker. [. . . ] 2) If you believe the ART unit is at fault, go to www. artproaudio. com. You may contact Customer Service for more assistance, or directly request a Return Authorization for service in the "resources" area of the website. 3) If you are returning the unit for service, pack the unit in its original carton or a reasonable substitute. The original packaging may not be suitable as a shipping carton, so consider putting the packaged unit in another box for shipping. [. . . ]