Marshall Power Brake

[hovis90]

Hi all, I was wondering if anyone could tell me what L1, L2 and C1 are doing in the Marshall Power Brake?



R3 is what attenuates the load.
Am I right in thinking L2 and C1 make an LC circuit/bandpass filter?

If anyone can explain this to me, and how it works - it would be greatly appreciated

[Enzo]

They are there to add some reactance to 8 ohm amplifier load R3. Those parts and R3 are a speaker emulator.


That emulated load is placed across the amp output in varying amount. Then the autoformer tap feeds the output to speaker in the desired amount of signal.

[Chuck H]

Right. Put another way, they make the load look more like a speaker to the amp so the amp will behave similar to how it would straight into a speaker.