FAQ .... Continued
A: Issue with the design...
Replace R280 with two series resistors. In the center or the two resistors take two diodes (one silicon and one germanium) two ground. See schematic below:
In the picture below, the germanium diode is replaced with a germanium transistor.. Heat drift is same, no current required... does the job. (Please forgive the lack of focus)
Q: When Limiting, VERY Low frequency output is caused by the limiting action. This shows up as a significant DC component (Speakers REALLY move).
A: Issue with the design...
The limiter action interacts with the bias level of the second stage. The bias servo operates to quickly and the result is sub 10 hz modulation that tracks limiting action. To correct this either change a capacitor or add an additional one in parallel to increase the time constant.
Change C2 from 2.2u/63v to 22u/63v. (Not easy to change cap without removing motherboard. Easiest thing to do is add a capacitor in parallel. See photo below.