Summary of the content on the page No. 1
User's Manual
MICtube
STEREO TUBE PREAMP
www.altoproaudio.com
Version 2.3 September 2005
English
Summary of the content on the page No. 2
result in damage to the product and SAFETY RELATED SYMBOLS possibly the user. Unplug the product before electrical storms CAUTION occur and when unused for long periods of RISK OF ELECTRIC SHOCK DO NOT OPEN time to reduce the risk of electric shock or fire. This symbol, wherever used, alerts you to the presence of un-insulated External Connection and dangerous voltages within the Always use proper ready-made insulated product enclosure. These are voltages mains cabling (power cord). Failure to d
Summary of the content on the page No. 3
Operating Conditions Servicing Always install in accordance with the Refer all servicing to qualified service manufacturer's instructions. personnel only. Do not perform any servicing other than To avoid the risk of electric shock and those instructions contained within the damage, do not subject this product to any liquid/rain or moisture. Do not use this User's Manual. product when in close proximity to water. Do not install this product near any direct heat source. Do not block areas of venti
Summary of the content on the page No. 4
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. The LTO line presents unparalleled analogue and digital products made by Musicians
Summary of the content on the page No. 5
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.
Summary of the content on the page No. 6
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 televi- sion studios. The LTO MICtube meets highest and no-compromise requirem
Summary of the content on the page No. 7
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. Supplementary Descriptions -Phantom Power Switch (4): This switch activates the +48 volts phantom power to supply condenser mics and any other devices requiri
Summary of the content on the page No. 8
-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 con- denser 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. To obtain the best possible S/N (Signal to Noise)
Summary of the content on the page No. 9
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. Wiring Configuration Either the 1/
Summary of the content on the page No. 10
Summary of the content on the page No. 11
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. Now, power up the entire equipment, if you wish to use a condenser mic requiring +48V phantom power, please press the Phantom Power Switch (4) (to avoi
Summary of the content on the page No. 12
6. TECHNICAL SPECIFICATIONS 6.1 Block Diagram 11 1 2 3 4 Block B Diagram D D 1 3 2 4 CH1 OUTPUT X1 U1(INA163) X3 X2 + PAD(20dB) 2 1 1 2 22 2 3 33 3 4 3 5 11 C 1 C 6 PHASE CH1 MICROPHONE INPUT TUBE-12AX7 1 3 2 4 X1 U2(INA163) X3 X2 + PAD(20dB) 1 CH2 OUTPUT 2 3 1 B B 4 2 5 PHANTOM 2 3 6 22 33 PHASE 3 CH1 MICROPHONE INPUT 11 1 +48VDC POWER SUPPLY +12VDC +15VDC VOLTAGE REGULATORUPPLY AC18V -15VDC A A 1 2 3 4
Summary of the content on the page No. 13
6.2 Specifications Input XLR Impedance 5K Ohm 1/4" High Z 1M Ohm TM Connectors Neutrik Combo Output XLR Balanced 100 Ohms 1/4" Unbalanced 100 Ohms Panel Controls Tube Drive 0dB to +40dB Gain 0dB to +30dB Phase Reverse 20dB Pad +48V Phantom Power Performance THD + Noise <0.5% Signal To Noise >90dB Power Supply Rejection >98dB Amplifier Type Dual Servo Meter 8-Digit LED -24dBu to +18dBu Physical Weight 1.05Kg 199(W) 153(D) 45(H)mm Dimensions Chassis Steel R Panel Brushed Aluminum ( LTO Style) Powe
Summary of the content on the page No. 14
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. Please fill out all the information carefully and genuinely, miswriting or absence of this card will
Summary of the content on the page No. 15
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. 14
Summary of the content on the page No. 16
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 NF00870-2.3
