Other Parts Discussed in Thread: OPA171,
I am trying to drive 64 Ohms impedence speaker using single-ended input. The input source is again 64 Ohms speaker preamplified by ~30dbs using OPA171. The whole system is operating on 12V.
My problem is at lower volume it gives distorted/garbled sound output and then with a slightly larger sound input the volume becomes too high (seems like the chip has AGC internal to it working in reverse fashion).
I tried different output filters and finally selected output filter calculated according to document slou032, with no improvement at all.
Would appreciate the reasoning behind this.