Technical specifications for a vintage amplifier like the Pioneer A445:

1. **Power Output**: The power output of the amplifier typically ranges from around 20 watts per channel to 50 watts per channel RMS (Root Mean Square), though this can vary.

2. **Frequency Response**: The frequency response typically spans from 20 Hz to 20 kHz, which covers the entire range of human hearing.

3. **Total Harmonic Distortion (THD)**: THD is often less than 0.5% at rated power, indicating low distortion levels.

4. **Signal-to-Noise Ratio (SNR)**: The SNR is usually greater than 70 dB, indicating a good signal-to-noise performance.

5. **Input Sensitivity**: The input sensitivity determines how sensitive the amplifier is to input signals. It is typically measured in millivolts (mV) or decibels (dB) and varies depending on the input source (e.g., phono, tuner, auxiliary).

6. **Input Impedance**: This refers to the electrical impedance presented by the amplifier's input circuits to the connected source components.

7. **Speaker Impedance**: The amplifier is usually compatible with speakers ranging from 4 ohms to 16 ohms impedance.

8. **Inputs and Outputs**: Common inputs include Phono (for turntables), Tape, AUX (Auxiliary), and possibly others like Tuner. Outputs often include connections for speakers and possibly headphones.

9. **Dimensions and Weight**: The dimensions and weight vary depending on the specific model but vintage amplifiers like the Pioneer A445 are typically relatively large and heavy compared to modern equivalents.

10. **Design**: Vintage amplifiers often feature a classic aesthetic with knobs and buttons for adjusting settings and selecting inputs.

11. **Build Quality**: Vintage amplifiers like the Pioneer A445 are known for their solid build quality and durable construction.