The 1176 will faithfully compress or limit at the selected ratio for transients, but the ratio will always increase a bit after the transient. The attack and release are program dependent, as is the ratio. The way the 1176 sounds, and specifically, the way all-button mode sounds, is partially due to its being a program dependent compressor. This became known as "All-button" mode or British mode, and is popular enough to be explicitly supported by modern clones of the 1176. However, British engineers discovered it was possible to push all four buttons in at once, an unexpected use case that led to unintended behaviour, with a substantial increase of harmonic distortion. The ratio buttons are designed to be mutually exclusive, so that pressing one ratio button deselects the others. Two units can be linked for proper stereo operation (not just dual mono).Release times are adjustable from 50 ms to 1100 ms (0.05–1.1 seconds).Four different compression ratios are available: 4:1, 8:1, 12:1, and 20:1.The threshold is set higher on higher ratios. The release time is program-dependent: it is quicker after transients to obtain a more consistent level, but it slows down after sustained and heavy compression to reduce pumping effects. The compression character is handled by attack and release times and four selectable compression ratios. As its predecessor, the 1176 utilizes soft knee compression and fixed threshold: compression amount is controlled through the input control. The 1176 uses a field-effect transistor (FET) to obtain gain reduction arranged in a feedback configuration.
Six UREI 1176LN (revision H) compressors stacked in individual flight cases
The original design was reproduced and revised thanks to the extensive design notes left by Bill Putnam. and Jim Putnam, and re-issued the 1176LN as its first product. However, the company was re-established as Universal Audio in 1999 by the sons Bill Putnam, Jr.
īill Putnam sold UREI in 1985 and Revision H was the last series produced by the original company. It was renamed to 1176LN and the face color changed to the now familiar solid black. Revision C, designed in 1970, saw one of the major design evolution, with less noise and harmonic distortion. The initial units (A and AB revisions) were available in 1967 and were informally referred as "blue stripe" for their blue-colored meter section. After successfully adapting the 108 tube microphone preamplifier into the new FET-based 1108, he redesigned the 175 and 176 variable-mu tube compressors into the new 1176 compressor. In 1966, Bill Putnam, engineer and founder of Universal Audio, began to employ the recently invented field-effect transistors (FET), replacing vacuum tubes in his equipment designs. One of 1176 predecessors, UA 175 Limiting Amplifier