The Technical Stuff
__________________________________________________________
- 25
-
Input Section
Figure 2 - Input Section
As shown in Figure 2, the 1176LN input section is comprised of an adjustable passive attenuator
followed by a transformer. The purpose of this section is to reduce the signal level so as not to
overdrive the FET based gain reduction stage. Additionally, the adjustable input level is used to
control the amount of compression. This input circuit was used in Revisions A-F. With Revision G, a
differential op-amp input instead of the attenuator / transformer input stage was used.
Gain Reduction Stage
Figure 3 - Gain Reduction Stage
As shown in Figure 3, gain reduction is achieved by a Field Effect Transistor (FET) which is used as a
variable resistor. In the 1176LN, the FET acts like a resistor whose resistance is controlled by the
