User's Manual HPA4 4-Channel HEADPHONE AMPLIFIER R LTO www.altoproaudio.com Version 2.
the recommended fuse type as indicated in this manual. Do not short-circuit the fuse holder. Before replacing the fuse, make sure that the product is OFF and disconnected from the AC outlet. SAFETY RELATED SYMBOLS CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN Protective Ground This symbol, wherever used, alerts you to the presence of un-insulated and dangerous voltages within the product enclosure. These are voltages that may be sufficient to constitute the risk of electric shock or death.
Preface Dear Customer: Thanks for choosing LTO HPA4 4-Channel Headphone Amplifier and thanks for choosing the one of results of LTO AUDIO TEAM job and researches. For our LTO AUDIO TEAM, music and sound are more than a job...are first of all passion and let us say...our obsession! We have been designing professional audio products for a long time in cooperation with some of the major brands in the world in the audio field.
TABLE OF CONTENTS 1. INTRODUCTION.....................................................................................................................................4 2. FEATURE LIST ......................................................................................................................................4 3. CONTROL ELEMENTS .........................................................................................................................4 3.1 The Front Panel 3.2 The Rear Panel 4.
1. INTRODUCTION Thank you very much for expressing your confidence in LTO products by purchasing our HPA4 4-Channel Headphone Amplifier. With the HPA4 you have acquired an extremely musical and flexible 4-Channel Headphone Amplifier. Featuring four stereo headphone amplifiers, the LTO HPA4 4-Channel Headphone Amplifier performs a number of necessary tasks, not all of which are headphone related.
1. Direct In Input The Direct In Input is used to feed the external program sources into the main signal path, comparing to the Main Input on the rear panel, this input presents the priority character. 2. Input Gain Control This control sets the input signal level coming from Main In. 3. Input Level Meter This meter tells you the level of the main input signal coming from Main/Direct In, and the range goes from -18dBu to +18dBu. 4.
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4. INSTALLATION & CONNECTION 4.1 Mains Connection This is a dual voltage unit. Please ensure that the LTO HPA4 4-Channel Headphone Amplifier is set to the correct supply voltage before plugging the power cord into the wall outlet, use the same fuse as marked on the fuse holder at the AC power connection socket. Do not insert power cable into the unit until voltage has been correctly set. Do not plug the power cable into AC power until voltage has been correctly set.
Balanced TIP RING SLEEVE Tip Ring Sleeve SLEEVE RING TIP 3 3 1 1 2 2 1 3 2 TIP RING SLEEVE Tip Ring Sleeve 1 2 1 2 3 3 Tip Ring 1 2 3 Sleeve Unbalanced 1 Tip Ring 3 2 Sleeve TIP RING SLEEVE Tip 1 3 2 Sleeve 1 2 3 1 2 3 1 TIP SLEEVE 2 3 1 2 3 Tip TIP SLEEVE Sleeve SLEEVE TIP Tip Ring TIP RING SLEEVE SLEEVE RING TIP Cent r e Screen Tip Sleeve Tip Ring Sleeve Sleeve Tip Cent r e Sleeve Screen Tip Ring Centre Sleeve Screen TIP SLEEVE TIP RING SLEEVE 2 2 3 3
Headphone output 1 INPUT LEVEL(dBu) 18 12 6 6 0 12 OUTPUT LEVEL(dBu) 18 CLIP 18 MUTE 12 6 0 MUTE L 6 12 Headphone output 2 OUTPUT LEVEL(dBu) 0 0 18 CLIP R 18 MUTE MONO 12 6 0 MUTE L 6 12 Headphone output 3 OUTPUT LEVEL(dBu) 0 0 18 CLIP R 18 MUTE MONO 12 6 0 MUTE L 6 12 Headphone output 4 OUTPUT LEVEL(dBu) 0 0 18 CLIP R 18 MUTE MONO 12 6 0 MUTE L 6 12 0 0 18 CLIP R MONO 3 2 R LTO HPA4 4 2 5 1 6 0 INPUT GAIN TREBLE AUX IN 4 TREBLE AUX
Background musical signals Headphone Output 1 Main Input INPUT LEVEL(dBu) 18 12 6 6 0 12 OUTPUT LEVEL(dBu) 18 CLIP 18 MUTE 12 L 6 MUTE 0 6 12 0 OUTPUT LEVEL(dBu) 0 18 CLIP R 18 MUTE MONO 6 12 L MUTE 0 6 12 OUTPUT LEVEL(dBu) 0 0 18 CLIP R 18 MUTE MONO 12 L 6 MUTE 0 6 12 OUTPUT LEVEL(dBu) 0 0 18 CLIP R 18 MUTE MONO 12 L 6 0 MUTE 6 12 0 0 18 CLIP R MONO 3 2 R LTO HPA4 4 2 5 1 6 0 INPUT GAIN MAIN SECTION TREBLE AUX IN 4 15 15 BASS HEADPH
6. TECHNICAL SPECIFICATIONS AUDIO INPUT MAIN input Connectors XLR and 1/4" jack Type HF filtered, servo balanced input Impedance 40 kOhms balanced, 20 kOhms unbalanced Max.input level +21 dBu balanced and unbalanced CMRR typ.40 dB, >55 dB @ 1kHz AUX IN and DIRECT IN input Connectors Type 1/4" TRS (tip=left, ring=right, sleeve=ground) Impedance >15 kOhms unbalanced Max.
7. WARRANTY 1. WARRANTY REGISTRATION CARD To obtain Warranty Service, the buyer should first fill out and return the enclosed Warranty Registration Card within 10 days of the Purchase Date. All the information presented in this Warranty Registration Card gives the manufacturer a better understanding of the sales status, so as to purport a more effective and efficient after-sales warranty service.
SEIKAKU TECHNICAL GROUP LIMITED No. 1, Lane 17, Sec. 2, Han Shi W. Road, Taichung, 401 Taiwan http://www.altomobile.com Tel: 886-4-22313737 email: info@altomobile.com Fax: 886-4-22346757 All rights reserved to ALTO Mobile. Due to continued development in response to customer feedback, product features, specifications and/or internal/external design may be changed without prior notice. No photocopying, translation or reproduction of any part of this user manual is allowed without prior written permission.
