User manual ASL INTERCOM ROXX 301

[. . . ] RoXX-Series 301 Personal Headphone Amplifier / Line Checker Manual The RoXX-Series 301 by ASL is a versatile professional stereo headphone amplifier for personal and portable use. The unit is battery powered and accepts all commonly used audio signals: balanced and unbalanced signals at microphone, line or speaker level. This Personal Headphone Amplifier has been designed with great precision. However, designing equipment like this is always a matter of finding compromises between: max. output power, distortion, power consumption, flexibility, mechanical aspects, costs etc. [. . . ] The Personal Headphone Amplifier can be modified so that Ni-MH cells can be charged in the unit. Consult your distributor for more information 18 Beltclip Open the battery compartment on the side of the unit A S L C O M M U N I C A T I O N S Y S T E M S RoXX-Series 301 Manual by turning the knurled screw anti-clockwise. Insert four AA-size 1. 5V batteries in the holder. Put the holder back into the unit, with the holders connection terminals pointing to the side where the beltclip is mounted. Close the battery compartment by putting back the little coverplate and turning the screw clockwise. The Personal Headphone Amplifier is now ready to operate on batteries. Always choose four identical batteries of the same age. Rechargeable NiCd or Ni-MH 1. 2V cells can be used as well. The RoXX 301 is protected against reverse voltage. The ASL RoXX -Series 301 can be switched on by pushing the power button (1). The unit will start whenever the total battery voltage is higher then 4. 0V. The unit will work until the total battery voltage drops below 2. 5V. When the unit switches off because the battery voltage is lower than 2. 5V, the batteries will start to recover a bit. The battery voltage rises, and when it exceeds 4. 0V, the unit will switch on again. By then, the battery voltage will again go down, resulting in switching off the unit at 2. 5V. This frequently and automatically switching on and off means that the batteries are empty and that they should be replaced. The ASL RoXX -Series 301 Personal Headphone Amplifier can be modified for charging four Ni-MH cells in the unit. Consult your distributor for more information. Whenever a RoXX 301 is prepared for charging Ni-MH cells, normal batteries should not been used anymore and reverse voltage protection for the cells does not work anymore!Mains Operation The ASL RoXX -Series 301 Personal Headphone Amplifier can be powered by mains by using a mains adaptor (not supplied with the RoXX 301). Choose an adaptor with an input voltage that matches the local mains voltage. The output of the adaptor needs to supply a DC-voltage between 9 and 24V at a current of 500mA (12 to 18V DC at a current of 1A when the RoXX 301 is prepared for charging Ni-MH cells). The DC-voltage can be either unregulated or regulated. [. . . ] The input labeled "Right/Mono" (14) should be left unused. It would be better to connect the pick-up to the Left/Stereo input and pressing the Stereo/Mono button. The input impedance is now 500k ohms and the pick-up will sound best. Volume Control The unbalanced input section and the balanced input section both have their own volume control knob as descriped in the above sections. The unbalanced input(s) and the balanced input can be used at the same time with the possibility to make a mix between the signals with the two volume control knobs (and the balance and pan knobs). [. . . ]