Universal-audio LA-3A Manuel d'utilisateur

Model LA-3AAUDIO LEVELERUniversal Audio Manual Number 65-1301Revision 1.53

7• When changing operating voltage, the fuse value must be changed as well.• Make sure the LA-3A is properly set for the voltage in your area before

8Stereo Setup / Calibration1. Set the STEREO ADJ control to full Clockwise.2. Set the PEAK REDUCTION knob to 0.3. Set the GR / OUTPUT switch to OUTPU

9WHAT COMPRESSORS DOThere are four main reasons to use a compressor:1. Prevent loud transients or volume bursts from overdriving a recording device o

10Compressing VocalsThe LA-3A is very popular for vocals. First of all, like many pieces of “vintage” gear the LA-3A has a unique “sonic signature” pr

11Dual UnitThe LA-3A shipping carton contains all the necessary brackets and hardware required for standard 19” rack mount. Bracket and hardware locat

12COMPRESSOR THEORY OF OPERATIONCompressor BasicsBefore we dig in to a description of the compressor circuit, it is useful to examine the general char

13In contrast to an amplier, whose job is to present a constant gain, a compressor varies its gain in response to the level of the input signal. Lar

14The T4 CellDIA GR AM OF TH E T 4 E LECT RO -OPT IC AL C EL LThe cell T4 is comprised of an electro-luminescent (EL) panel and a photoelectric ce

15milliseconds) to approximately half of its off resistance. The remainder of its release can take place over as much as several seconds.The next asp

16HISTORICAL NOTESNAT “K ING” C OLE WI TH BI L L PUT N AM SR.Bill Putnam Sr. was awarded the 2000 Technical Grammy for his multiple contribution

iiIMPORTANT SAFETY INSTRUCTIONSBefore using this unit, be sure to carefully read the applicable items of these operating instructions and the safetysu

17The 610 PreampThe 2-610 was inspired by the Putnam-designed 610 console built in 1960 for his United Recording facility at 6050 Sunset Boulevard in

18Universal Audio 175 and 176 vacuum tube limiters, the 1176LN retained the proven qualities of these industry leaders, and set the standard for all l

330 Encinal Street • Santa Cruz CA • 95060-2101 • www.uaudio.com • toll-free: 866-UAD-1176 • voice: 831-466-3737 • fax: 831-466-3775LA-3ASession Reca

iiiTHE LA-3A AUDIO LEVELERThank you for purchasing the LA-3A Audio Leveler. The LA-3A is a solid-state version of Universal Audio’s vacuum tube based

1TABLE OF CONTENTSLA-3A SPECIFICATIONS 3LA-3A FRONT PANEL 4 Peak Reduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Gai

2COMPRESSOR THEORY OF OPERATION 12 Compressor Basics. . . . . . . . . . . . . . . . . . . . . . . . . . . 12 The T4 Cell. . . . . . . . . . . .

3LA-3A SPECIFICATIONSBalanced Line Input Impedance. . . . . . . . 600Ω oatingMax. Input Level. . . . . . . . . . . . . . . . . . . . -0dBm @ 50dB

4LA-3A OPERATING INSTRUCTIONSThe LA-3A is a solid state compressor that automatically reduces the level of loud signals in order to maintain a more co

5function is determined using the two-position switch below the GAIN knob to the left of the meter. When OUT-PUT is selected, a meter reading of 0 co

650/30 dB Gain Switch The 50/30 dB GAIN switch is an input pad to prevent high output devices from overdriving the input transform-er of the LA-3A. Se