User's Manual MICtube STEREO TUBE PREAMP www.altoproaudio.com Version 2.
result in damage to the product and possibly the user. Unplug the product before electrical storms occur and when unused for long periods of time to reduce the risk of electric shock or fire. SAFETY RELATED SYMBOLS CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN 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.
Operating Conditions Servicing Always install in accordance with the manufacturer's instructions. To avoid the risk of electric shock and damage, do not subject this product to any liquid/rain or moisture. Do not use this product when in close proximity to water. Refer all servicing to qualified service personnel only. Do not perform any servicing other than those instructions contained within the User's Manual. Do not install this product near any direct heat source. Do not block areas of ventilation.
Preface Dear Customer, Thanks for choosing LTO Stereo Tube Preamplifier and thanks for choosing one of the 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 CONTENT 1. INTRODUCTION ............................................................................................5 2. FEATURE LIST ..............................................................................................5 3. CONTROL ELEMENTS .................................................................................5 3.1 The Front Panel a. Guidepost of The Front Panel b. Supplementary Descriptions 3.2 The Rear Panel a. Power Supply Connection b. Analogue Inputs/Outputs 4.
1. INTRODUCTION Thank you very much for expressing your confidence in LTO products by purchasing our MICtube Stereo Tube Preamplifier. With the MICtube you have acquired an extremely musical and flexible Stereo Microphone Preamplifier which is based on many years of experience and findings in amplifier technology and is used through the world in renowned studios, sound reinforcement systems as well as in broadcast and television studios.
a. Guidepost of the front panel (1) Power LED (2) CHANNEL 1 Output Level Display LED (3) CHANNEL 2 Output Level Display LED (4) Phantom Power Switch (5)(6) Phase Reverse Switch (7)(8) 20dB PAD (9)(10) Combination Microphone (XLR) and Instrument (1/4 inch) input (11)(13) Input Gain Control (0 to 30 dB) (12)(14) Drive Control (0 to 40 dB) b.
-10dBV ) or professional level (+4dbu). When the gain is too low, the tube effect becomes less audible and the S/N (Signal to Noise) ratio deteriorates. Generally, Dynamic mics and instruments without preamps will require more gain than condenser mics and instruments that have a built-in preamp. If you should require more signal out of the preamp for a hotter recording level, cranking up the gain should provide all the signal that you'll need.
4. INSTALLATION & CONNECTION: 4.1 Mains Connection - Please ensure that the LTO MICtube Stereo Microphone Preamplifier is connected to the correct supply voltage before operating this unit. - Only use the 18VAC AC/AC Adaptor provided by LTO. 4.2 Audio Connection The LTO MICtube Stereo Tube Preamp presents with balanced XLR connectors and 1/4" TRS phone jack and it can be interfaced by several ways to support a variety of applications without any signal loss. a.
Balanced Unbalanced 1 2 3 Tip Sleeve TIP SLEEVE Tip Ring TIP RING SLEEVE 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 1 1 2 3 2 3 4.3 Rack Mounting 5. APPLICATIONS 5.
On the output side, which may damage subsequent devices, so you should turn down all the level controls beforehand, or you can press the 20dB Pad (7/8) to attenuate the incoming signal level about 20dB, then hook up a microphone to the XLR and 1/4" Combination Input (9/10), use either the jack or XLR output connectors to connect the audio system.
11 A B C D X3 X2 1 2 3 4 5 6 X1 1 CH1 MICROPHONE INPUT X3 X2 1 2 3 4 5 6 X1 CH1 MICROPHONE INPUT 1 + PAD(20dB) U2(INA163) + PAD(20dB) U1(INA163) -15VDC +15VDC +12VDC +48VDC 2 2 POWER SUPPLY VOLTAGE REGULATORUPPLY PHANTOM TUBE-12AX7 Block Diagram 3 AC18V 3 3 1 3 1 PHASE PHASE 2 2 4 2 22 33 3 11 1 1 3 2 4 2 22 33 3 11 1 1 3 2 4 4 CH2 OUTPUT CH1 OUTPUT A B C D 6. TECHNICAL SPECIFICATIONS 6.
6.2 Specifications Input XLR Impedance 1/4" High Z Connectors 5K Ohm 1M Ohm NeutrikTM Combo XLR Balanced 1/4" Unbalanced 100 Ohms 100 Ohms Tube Drive Gain Phase Reverse 0dB to +40dB 0dB to +30dB Output Panel Controls 20dB Pad +48V Phantom Power Performance THD + Noise Signal To Noise Power Supply Rejection Amplifier Type <0.5% >90dB >98dB Dual Servo 8-Digit LED -24dBu to +18dBu Weight Dimensions Chassis Panel 1.
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.
3.5 In no event shall LTO be liable for any incidental or consequential damages. Some states do not allow the exclusion or limitation of incidental or consequential damages, so the above exclusion or limitation may not apply to you. 3.6 This warranty gives you the specific rights, and these rights are compatible with the state laws, you may also have other statutory rights that may vary from state to state.
SEIKAKU TECHNICAL GROUP LIMITED No. 1, Lane 17, Sec. 2, Han Shi West Road, Taichung 40151 Taiwan http://www.altoproaudio.com Tel: 886-4-22313737 email: alto@altoproaudio.com Fax: 886-4-22346757 All rights reserved to ALTO. All features and content might be changed without prior notice. Any photocopy, translation, or reproduction of part of this manual without written permission is forbidden. Copyright c 2005 SEIKAKU GROUP NF00870-2.