Instruction/ maintenance manual of the product 2-1176 Universal Audio
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Model 2-1176 Dual 1176LN Limiting Amplifier Universa l Audio P art Num ber 65- 00047 Universal Audio, Inc. Customer Service & Tech Support: 1-877-MY-AUDIO Business, Sales & Marketing: 1-866-440-1176 www.
- i - Notice This manual provides general information, preparation for use, installation and operating instructions for the Universal Audio 2-1176. The information contained in this manual is subject to change without notice.
A Letter From Bil l Putnam, Jr. ___________________________________________________________ - ii - Thank you for purchasing the 2-1176 Dual 1176LN Limiting Amplifier. My father designed the original 1176 back in 1966, and he was very pleased with his accomplishment.
Importa nt Safet y Instruc tions ___________________________________________________________ - iii - Befo re u sing thi s un it, b e su re t o ca refu lly r ead the app lica ble item s o f the se o per atin g in stru ctio ns a nd t he safe ty s ugg estio ns.
Table of Content s __________________________________________________________ - 1 - A Letter From Bill Putnam, Jr. ................................................................................................................ Important Safety Instructions .
The Two Page, Tw o Minute Guide To Getting S tarted __________________________________________________________ - 2 - No one likes to read owner’s manuals. We know that. We also know that you know what you’re doing—why else would you have bought our product? So we’re going to try to make this as easy on you as possible.
The Two Page, Tw o Minute Guide To Getting Started __________________________________________________________ - 3 - Step 7: Set the Attack and Release knobs for both channels fully counterclockwise (to their SLOW position).
Front Pa nel __________________________________________________________ - 4 - NOTE: The 2-1176 provides two channels, each of which have identical front panel controls. (1) Attack - Sets the amount of time it takes the 2-1176 channel to respond to an incoming signal and begin gain reduction.
Front Pa nel __________________________________________________________ - 5 - (4) Meter - A standard VU meter that displays either the amount of gain reduction or output level for the channel, depending upon the setting of the Meter Function switch. ( see #3 above ) Occasionally, one or both meters may require calibration.
Front Pa nel __________________________________________________________ - 6 - (8) LINK / DUAL switch - Sets the 2-1176 to either dual mono or stereo linked operation. When set to the down (DUAL) position, the 2-1176 operates as two separate compressors, with the two channels operating completely independent of one another.
Rear Pa nel __________________________________________________________ - 7 - NOTE: The 2-1176 provides two channels, each of which have identical rear panel controls. (1) Line INPUT - Connect line-level input signal for each channel to these balanced XLR connectors.
Interco nnections __________________________________________________________ - 8 -.
Insider’s Secrets __________________________________________________________ - 9 - Whatever you can do with an 1176LN, you can do with a 2-1176... two times over. In addition, Link mode allows the 2-1176 to process not just monophonic signals, but stereo signals such as drum or backing vocal submixes.
Insider’s Secrets __________________________________________________________ - 10 - Jim Scott, who won a Grammy for Best Engineered Album for Tom Petty’s Wildflowers , adds, “I use 1176s real conservatively and they still do amazing things. I always use them on vocals.
Insider’s Secrets __________________________________________________________ - 11 - “When I am mixing,” Johns adds, “I mult the bass drum and the snare. The bass drum will not be even, so the first bass drum track—the one that doesn’t have the 1176 on it—gets to breathe.
Insider’s Secrets __________________________________________________________ - 12 - “Treating some electric guitar sounds that had been previously recorded,” Curwin added, “allowed the opportu.
Insider’s Secrets __________________________________________________________ - 13 - Controlled Distortion The unique sonic characteristics of the 2-1176 make it an effective tone shaper as well.
Insider’s Secrets __________________________________________________________ - 14 - mode. Adding a bit of slam-compressed audio to the mix produced a brighter mix without high- frequency overload. It also really helped both drums and guitars maintain a strong place in the mix without overwhelming vocals and bass.
The Tech nical St uff __________________________________________________________ - 15 - History o f the 11 76 The original Universal Audio 1176, designed by Bill Putnam, was a major breakthrough in limiter technology – the first true peak limiter with all transistor circuitry offering superior performance and a signature sound.
The Tech nical St uff __________________________________________________________ - 16 - Another significant redesign occurred in 1973. The revision F output stage was modified to provide higher output current capability by using a push-pull circuit design borrowed from Universal Audio's new 1109 preamplifier.
The Tech nical Stu ff __________________________________________________________ - 17 - Compre ssor / Lim iter Basi cs The function of a compressor is to automatically reduce the level of peaks in an .
The Tech nical St uff __________________________________________________________ - 18 - Input Signal and Threshold The first and perhaps most significant factor in compression is the level of the input signal. Large (loud) input signals result in more gain reduction, while smaller (softer) input signals result in less gain reduction.
The Tech nical St uff __________________________________________________________ - 19 - maximum value. At very high ratios of 20:1 or greater (some limiters even offer a theoretical infinite ratio of .
The Tech nical St uff __________________________________________________________ - 20 - Output (Makeup Gain) Finally, output controls are employed to make up for the gain reduction applied by the gain reduction circuitry; on the 2-1176, this is the function of each channel’s Output knob.
The Tech nical St uff _______________________________________________________________________ - 21 - 1. While in Link mode, send stereo signal to the 2-1176 but monitor the left channel only.
The Tech nical St uff __________________________________________________________ - 22 - To make such a cable, first acquire the following components: (1) Female XLR cable connector (1) Male XLR cable .
The Tech nical St uff __________________________________________________________ - 23 - Mainten ance In formatio n Meter Calibration The 2-1176 meters may occasionally need to be calibrated. This is accomplished by adjusting the Zero Set potentiometer, located through a small hole on the front panel between each channel’s Input and Output knobs.
The Tech nical Stu ff __________________________________________________________ - 24 - Changing Fuses The AC power fuse is located on the power supply circuit board inside the 2-1176, directly behind the AC power connector, accessed by removing the top panel of the 2-1176.
The Tech nical St uff __________________________________________________________ - 25 - 2-1176 C ircuit De tails The fundamental problem facing Bill Putnam Sr. when he began designing the 1176 limiter was how to keep its FET operating within its linear region in order to keep distortion sufficiently low.
The Tech nical St uff __________________________________________________________ - 26 - Input Section Figure 2 - Input Section As shown in Figure 2, the 1176 input section is comprised of an adjustable passive attenuator followed by a transformer.
The Tech nical St uff __________________________________________________________ - 27 - As shown in Figure 3, gain reduction is achieved by a Field Effect Transistor (FET) which is used as a variable resistor. In the 1176, the FET acts like a resistor whose resistance is controlled by the voltage applied to its gate.
The Tech nical St uff __________________________________________________________ - 28 - Output Amplifier The output amplifier is a Darlington pair followed by a class A stage based on a 2N3053 transistor. The 1176 output stage was essentially the same as the Universal Audio 1108 pre-amplifier.
The Tech nical St uff __________________________________________________________ - 29 - As shown in Figure 5, this circuit controls the amount of compression as well as the attack and release times of the limiter. The input to this circuit is taken from the output of the preamplifier section, just before the volume control potentiometer (R23).
Glossary of Terms __________________________________________________________ - 30 - Ambient noise - Low-level noise created by environmental factors such as fans, air conditioners, heaters, wind noise, etc. Attack time - Describes the amount of time it takes compressor circuitry to react to and reduce the gain of incoming signal.
Glossary of Terms __________________________________________________________ - 31 - dBm - Short for “decibels as referenced to milliwatt,” dissipated in a standard load of 600 ohms.
Glossary of Terms _______________________________________________________________________ - 32 - Peak reduction - A synonym for compression or limiting. Program dependent - Refers to a parameter that varies according to the characteristics of the incoming signal.
Recall S heet __________________________________________________________ - 33 -.
Specific ations _______________________________________________________________________ - 34 - Input Impedance 15 k Ω , 600 Ω selectable Output Load Impedance 600 Ω (floating) Frequency Response 20 Hz to 20 kHz ± 1 dB Gain 40 dB, ± 1 dB Distortion > 0.
Addition al Resou rces/Pro duct Re gistration/W arranty/ Service & Suppo rt __________________________________________________________ - 35 - Addition al Resou rces We’ve got a pretty cool website, if we may say so ourselves. Check us out at http://www.
An important point after buying a device Universal Audio 2-1176 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Universal Audio 2-1176 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Universal Audio 2-1176 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Universal Audio 2-1176 you will learn all the available features of the product, as well as information on its operation. The information that you get Universal Audio 2-1176 will certainly help you make a decision on the purchase.
If you already are a holder of Universal Audio 2-1176, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Universal Audio 2-1176.
However, one of the most important roles played by the user manual is to help in solving problems with Universal Audio 2-1176. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Universal Audio 2-1176 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
