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Phil Allison[_4_] Phil Allison[_4_] is offline
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Default Questions About the Event TR5 Schematic

Paul wrote:


The subsonic filter looks to be a unity-gain, non-inverting
topology. The series cap C6 is obviously a high-pass filter, but
how are the values for R10 and R11 chosen? Where is the "RC time
constant" that determines when the low frequencies start rolling off?



** The active filters used are all "Sallen-Key" types.

http://sim.okawa-denshi.jp/en/OPstool.php

Similar S-K filter stages are connected around the two LM3886 power amps - after scaling each output (eg R7 & R8) to give unity gain. This doubles the roll off slopes to 24db/octave.


..... Phil