Hairball Audio

HB76 - Mono FET Compressor

HB76

In 1966 Bill Putnam Sr. put the finishing touches on the first Urei 1176. In the 10 years that followed, Putnam would release 8 different revisions (A-H) and create one of recording industries most acclaimed compressors. Along with the LA-2A (also Putnam's design), the 1176 compressor is a studio cornerstone.

The HB76 uses Mnats J printed circuit boards. Similar to the Gyraf 1176, the Mnats version is based on the Urei 1176LN revision F. All 1176s compress in the same manner, using a Field Effect Transistor as a voltage variable resistor, in which the resistance between the drain and the source terminals is controlled by a voltage applied to the gate. The differences between the revisions can mostly be found in the input and output stages. Revisions A-E used a class A input and output stage. This resulted in a fair amount of "musical distortion" or "color", a sound which defined the early 1176 revisions.

Revisions F-H changed the output stage to a class A/B "push-pull" circuit. This provided more output drive and a flatter EQ response that some favored. The Mnats version used the revision F output stage and incorporates options for a transformerless input (Revisions G-H) or a balanced input in which several transformer options are available.

The HB76 uses transformers on the input and output. High quality Lundahl (made in Sweden) transformers are used on either end providing a clean and clear signal from start to finish. The focus is placed on the compression, allowing the 1176 FET gain reduction circuit to work it's magic. Your ears will be amazed!

Incorporating 1176 knobs and pushbutton switches, the HB76 has not only the sound of the 1176, but the feel and look. Please stop by our store to view our inventory of FET compressor knobs and switches.

Build info:
Mnats Website

Additional Resources:
Gyraf's 1176 Page
Prodigy-Pro Forum
Hairball Audio Store

 

Coordinates

N 47°31'59.300"
W 122°23'08.501"

email: info@hairballaudio.com