1176LN Compressor Limiter
The original Universal Audio 1176LN 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. Evolved from the popular Universal Audio 175 and 176 vacuum tube limiters, the 1176LN retained the proven qualities of these industry leaders, and set the standard for all limiters to follow.
I’m currently in the process of building two compressors based on the 1176LN revision F originally designed by Bill Putnam at Urei in 1966. The first major modification to the 1176 circuit was designed by Brad Plunkett to reduce noise, thus the 1176LN, where LN stands for low noise. They are now being sold by Universal Audio. Gyraf Audio, a Danish audio electronics research and development company has provided information for construction and calibration of a clone of the 1176LN whose design and performance is very close to the original.
The Gyraf Audio design is based on the UREI 1176LN Revision F with a push-pull output stage rather than the previous class A output. The class A output on the original required a difficult to find output transformer with a tertiary feedback winding. The schematic can be found here.
I received some circuit boards from Mnats and have populated them. Its ready to go but the project is now on hold until I can find a suitable chassis and faceplate design.