Stk411-210e Circuit | Diagram

| Component | Value | Purpose | |-----------|-------|---------| | Rf (pin1-6) | 22kΩ | Feedback resistor | | Ri (pin2 to GND) | 1kΩ | Input grounding resistor | | Ci (series with input) | 2.2µF | DC blocking (optional) | | Cc (between pin 7 and 6) | 100µF | Bootstrap / supply filtering | | Cs (V+ to GND) | 100µF + 0.1µF | Power decoupling | | Zobel (pin6 to GND) | 10Ω + 0.1µF | High-frequency stability |

| Component | Value | Voltage Rating | Quantity | | :--- | :--- | :--- | :--- | | Resistor (R1) | 47kΩ (Input) | 1/4W | 2 | | Resistor (R2) | 100kΩ (Cin to GND) | 1/4W | 2 | | Resistor (R3) | 560Ω (Feedback to GND) | 1/2W | 2 | | Resistor (R4) | 47kΩ (Feedback loop) | 1/4W | 2 | | Resistor (R5) | 10Ω (Zobel) | 2W | 2 | | Resistor (R6) | 2.2Ω (Output inductor parallel) | 2W | 2 | | Capacitor (C1) | 1.8µF (Input coupling) | 50V (Film) | 2 | | Capacitor (C2) | 100pF (Feedback compensation) | 50V (Ceramic) | 2 | | Capacitor (C3) | 0.1µF (Zobel) | 100V (Polyester) | 2 | | Capacitor (C4) | 100µF (Bootstrap) | 100V (Electrolytic) | 2 | | Inductor (L1) | 1µH (Air core, 10 turns) | N/A | 2 |

The STK411-210E requires a split supply (±Vcc). A recommended supply: stk411-210e circuit diagram

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.

Left Channel Path:

Right Channel Path:

Shared Power & Control:

| Symptom | Likely Cause | Fix | |-----------------------|------------------------------------|--------------------------------| | No output, IC hot | Short in output or bad IC | Check Zobel network, replace IC| | Distorted sound | Low supply voltage or bad caps | Check ±Vcc, replace bootstrap cap| | One channel dead | Broken pin, cracked IC | Reflow solder, replace IC | | Oscillation (RF noise)| Missing Zobel network or long leads| Add R4/C4 close to IC | | Power-on pop | No input RC delay | Add 10k/47µF to ground at input |

| Pin | Name | Description | |-----|------------|------------------------------------| | 1 | INPUT(-) | Inverting input (Ch1) | | 2 | INPUT(+) | Non-inverting input (Ch1) | | 3 | GND | Ground | | 4 | N.C. | Not connected | | 5 | V- | Negative power supply | | 6 | OUTPUT | Speaker output (Ch1) | | 7 | V+ | Positive power supply | | 8 | N.C. | Not connected | | 9 | INPUT(+) | Non-inverting input (Ch2) | | 10 | INPUT(-) | Inverting input (Ch2) | | Component | Value | Voltage Rating |

Note: Some datasheets show 12-pin versions — verify your exact IC. STK411-210E is typically 10-pin.