Model 6176 Channel Strip Universal Audio Manual Number 65-0013 Revision 1.2 Universal Audio, Inc. www.uaudio.com 2125 Suite A, Delaware Ave. Santa Cruz, CA 95060 (831) 466-3737 voice (831) 466-3775 fax www.uaudio.com The 6176 Channel Strip Thank you for purchasing the 6176 Channel Strip. This unit brings together 1 channel of our 2-610 Mic Pre with an 1176 Limiter. The 610B was inspired by the microphone preamp section of the 610 console designed by my father, M.T. "Bill" Putnam, in the 1950s. The 610 was a rotary-control console and was the first console of the modular design. Although technologically simple compared to modern consoles, the 610 possessed a warmth and character that kept it in demand for decades. As a prominent part of my father's United/Western studios, the 610 was used on many classic recordings by Frank Sinatra and Sarah Vaughan. The Beach Boys Pet Sounds, the Doors LA Woman, and Van Halen's debut album were all recorded on the 610. The legendary Wally Heider used the 610 in his remote truck for many of his best-known live recordings. At Ocean Way Studios (formerly United), the 610 is lovingly preserved and still used in Studio B. You may be familiar with the fact that there were many versions of the 1176 produced throughout the years. We patterned our reproduction on the D/E versions. These versions were characterized by the transformer input stage, LN circuitry, and the class A (1108 style) output stage. Later versions replaced the class-A output stage with a push-pull class-AB output stage, and eventually replaced the transformer input with a differential op-amp circuit. That highly recognizable blackface 1176 sound was best captured by the version that we are reproducing. In addition to the 1176LN and 2-610, Universal Audio has released reproductions of the classic Teletronix LA-2A Leveling Amplifier and the 2108 microphone preamplifier which is based on the 1108 line amps that were used in my father's studios. Universal Audio also creates software emulation's of our vintage hardware that run on our UAD-1 DSP card as well as Digidesign's Pro Tools platform. All of these products are designed to meet the demands of the modern recording studio, yet retain the character of vintage equipment. These products have been quite an enjoyable adventure to develop and we're sure the next phase will be even more fun! We thank you for your support and we thank my father, Bill Putnam. Thank you, Bill Putnam IMPORTANT SAFETY INSTRUCTIONS Before using this unit, be sure to carefully read the applicable items of these operating instructions and the safety suggestions. Afterwards keep them handy for future reference. Take special care to follow the warnings indicated on the unit itself, as well as in the operating instructions. 1. 2. 3. Water and Moisture ­ Do not use the unit near any source of water or in excessively moist environments. Object and Liquid Entry ­ Care should be taken so that objects do not fall, and liquids are not spilled, into the enclosure through openings. Ventilation ­ When installing the unit in a rack or any other location, be sure there is adequate ventilation. Improper ventilation will cause overheating, and can damage the unit. Heat ­ The unit should be situated away from heat sources, or other equipment that produce heat. Power Sources ­ The unit should be connected to a power supply only of the type described in the operating instructions, or as marked on the unit. Power Cord Protection ­ AC power supply cords should be routed so that they are not likely to be walked on or pinched by items placed upon or against them. Pay particular attention to cords at plugs, convenience receptacles, and the point where they exit from the unit. Never take hold of the plug or cord if your hand is wet. Always grasp the plug body when connecting or disconnecting it. Grounding of the Plug ­ This unit is equipped with a 3-wire grounding type plug, a plug having a third (grounding) pin. This plug will only fit into a grounding-type power outlet. This is a safety feature. If you are unable to insert the plug into the outlet, contact your electrician to replace your obsolete outlet. Do not defeat the purpose of the grounding-type plug. 8. 4. 5. 6. 7. Carts and Stands ­ The unit should be used only with a cart or stand that is recommended by the manufacturer. The unit and cart combination should be moved with care. Quick stops, excessive force and uneven surfaces may cause the unit and cart combination to overturn. 9. Wall Or Ceiling Mount ­ The unit should be mounted to a wall or ceiling only as recommended by the manufacturer. 10. Cleaning ­ The unit should be cleaned only as recommended by the manufacturer. 11. Nonuse Periods ­ The AC power supply cord of the unit should be unplugged from the AC outlet when left unused for a long period of time. 12. Damage Requiring Service ­ The unit should be serviced by a qualified service personnel when: a) The AC power supply cord or the plug has been damaged: or b) Objects have fallen or liquid has been spilled into the unit; or c) The unit has been exposed to rain; or d) The unit does not operate normally or exhibits a marked change in performance; or e) The unit has been dropped, or the enclosure damaged. 13. Servicing ­ The user should not attempt to service the unit beyond that described in the operating instructions. All other servicing should be referred to qualified service personnel. Notice This manual provides general information, preparation for use, installation and operating instructions for the Universal Audio 6176 Channel Strip. The information contained in this manual is subject to change without notice. Universal Audio, Inc. makes no warranties of any kind with regard to this manual, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Universal Audio, Inc. shall not be liable for errors contained herein or direct, indirect, special, incidental, or consequential damages in connection with the furnishing, performance, or use of this material. Copyright © 2003 Universal Audio, Inc. All rights reserved. This manual and any associated software, artwork, product designs, and design concepts are subject to copyright protection. No part of this document may be reproduced, in any form, without prior written permission of Universal Audio, Inc. Trademarks LA-2A, 1176LN, 2-610, 2108, 6176 and the Universal Audio, Inc. logo are trademarks of Universal Audio, Inc. Other company and product names mentioned herein are trademarks of their respective companies. 2 Table of Contents 610B Specifications .......................................................................................4 1176 Specifications .......................................................................................5 610B Operating Instructions...........................................................................6 610B Front Panel.................................................................................6 Input Select.............................................................................7 Gain ........................................................................................7 Level.......................................................................................8 Pad..........................................................................................8 Polarity ...................................................................................8 EQ Controls ............................................................................8 Meter Function ..........................................................................8 +48 V (Phantom Power)..........................................................8 Join / Split...............................................................................9 1176 Operating Instructions .........................................................................10 1176 Front Panel .............................................................................10 Input Level .............................................................................10 Output Level............................................................................11 Attack Control .........................................................................11 Release Control........................................................................11 Compression Ratio...................................................................11 Meter Function ........................................................................12 Meter Calibration.....................................................................12 Join / Split................................................................................12 Stereo Operation................................................................................12 6176 Rear Chassis........................................................................................13 Connectors ........................................................................................13 1176 Input Loading ..........................................................................13 Fuse...................................................................................................13 Voltage Select ...................................................................................14 History .........................................................................................................15 3 610B Specifications Microphone Input Impedance Balanced Line Input Impedance Hi-Z Input Impedance Maximum Microphone Input Level Maximum Output Level Internal Output Impedance Recommended Minimum Load Frequency Response Maximum Gain Signal-to-Noise Ratio Tube Complement Power Requirements Selectable, 500 W or 2k W 20k W Selectable, 2.2M W or 47k W +18 dBu (2K input Imp. & 15 dB Pad in) +20 dBm 80 W 600 W 20 Hz to 20 kHz +0, -1 dB 65 dB (500 W input impedance) > 90 dB @ maximum gain One 12AX7A and one 6072A per channel 115V/230V Special Note: The 610B is virtually identical to one side of a 2-610 with two exceptions. The front panel ­15dB Pad and a different power supply. We have added a MOSFET regulator to the 610B's High Tension power supply. This regulator, besides keeping the voltage stable, reduces the supplies noise contribution to a negligible level. 4 1176LN Specifications Input Impedance: Output Load Impedance: External Connections: Frequency Response: Gain: Distortion: Selectable, 15k W or 600 W 600 W (floating) XLR Connectors +/- 1 dB. 20Hz to 20 kHz 40 dB, +/- 1dB Less than 0.5% T.H.D. from 50 Hz to 15 kHz with limiting, at 1.1 seconds release setting. Output of +22 dBm with no greater than 0.5% T.H.D. Greater than 75 dB Adjustable from 20 to 800 microseconds. Adjustable from 50 milliseconds to 1.1 seconds. Using 1176 SA stereo interconnect accessory Signal-Noise Ratio: Attack Time: Release Time: Stereo Interconnection: General: Power Requirements: Dimensions: Weight: 115V / 230V operation 3.5" vertical, for mounting in standard 19" rack (2RU). 12 lbs. (Shipping weight 14.5 lbs.) 5 610B Operating Instructions The 610B is a vacuum-tube microphone/instrument/line preamplifier. The main circuit has two gain stages that utilize a dual-triode tube operating in a class A single-ended configuration. Variable negative feedback is applied to both of these stages to control gain, distortion, and frequency response. Balanced inputs and outputs are transformer coupled. 610B Front Panel (left side) The front panel has Input Select, Gain, Level, EQ, Pad and Polarity controls as well as a Hi-Z Input. The center section contains (Figure 2) the power ON/OFF switch, pilot light, JOIN-SPLIT switch and a 48 V phantom power ON/OFF switch. Each control is discussed in the following sections. GAIN POLARITY PAD HIGH FREQUENCY HIGH BOOST/CUT -5 -10 0 +5 GAIN +10 -15 dB 4 PAD 3 2 1 0 Hi-Z LEVEL 5 HIGH 7K 6 7 8 9 10 200 70 10K 4.5K LOW 100 -3 -4.5 -6 -3 -4.5 -6 -1.5 0 +1.5 +3 +4.5 +6 -9 +9 Mic 500 Line Hi-Z 47K 2.2M OUT ø INø 2.0K -1.5 0 +1.5 +3 +4.5 +6 -9 +9 INPUT SELECT LEVEL LOW BOOST/CUT LOW FREQUENCY INSTRUMENT INPUT Figure 1: 610B Front Panel 6 610B Input Select The Input Select switch determines which input is active: Mic, Line, or Hi-Z. Within both the Mic and Hi-Z areas, the switch includes two settings to select between input impedances. · Mic: Selects the signal from the rear-panel, balanced, MIC INPUT XLR connector. The impedance for the MIC INPUT can be set to 500 W or 2K W. Switching between these two positions while listening to a connected microphone may reveal a different tonal quality and / or gain. A typical mic preamplifier should have an input impedance equal to about 10 times the mic output impedance. For example, if your mic has an output impedance between 150 W and 200 W, set the switch to the 2K position. However, since making music is not necessaril ...