R7 (10k) and C7 (2n2) form a first-order LPF with a corner frequency of 7.2kHz. Increasing either of those would lower the frequency and cut more high end.
R7 (10k) and C7 (2n2) form a first-order LPF with a corner frequency of 7.2kHz. Increasing either of those would lower the frequency and cut more high end.