Stk411-210e Circuit Diagram -

For exact PCB layouts and component values:

                     +21V ──┐
                           ┌┴┐ Cc
                           │ │ 100µF
                           └┬┘
                            │
Input1 ──┬── 10µF ── 47kΩ ──┤ Pin2 (IN1)
         │                   │
        GND                  │
         │                   │
         └── 47kΩ ───────────┤ Pin1 (NF1)
                             │
                        ┌────┤
                        │    │
                     22kΩ    │
                        │    │
                       GND   │
                             │ Pin5 (OUT1) ──┤ Speaker 8Ω
                             │                │
                             │               GND
                             │
                       100pF ─┐ (Zobel)
                        10Ω  ─┤
                             ─┘
                            GND
(Repeat for Channel 2: Pin11, Pin12, Pin8)

The STK411-210E requires a split supply (±Vcc). A recommended supply:

Power calculation:
For ±21V into 8Ω: Max output swing ≈ ±19V (losses). Pmax = (19²)/(2×8) ≈ 22W peak, but thermally limited to 15W continuous per channel. stk411-210e circuit diagram

Below is a simplified but complete stereo circuit using the STK411-210E:

                          +Vcc   +Vcc
                            |      |
                            └──┬───┘
                               │
                         10µF  │  100µF
                          ┌┐   │   ┌┐
                          ││  (7)  ││
          CH1 INPUT ──┬─22kΩ──2│   │6─┬─ TO SPEAKER (R)
                      │        │  STK  │  │
                      │   47pF │ 410E  │  │
                      └─47kΩ──1│      3│─GND
                              │       │
          CH2 INPUT ──┬────9   │       │
                      │      10│       │47pF
                      └───────────────┘
                   GND──────3────────GND
                           │
                          -Vcc