1. What is an Analog Unpowered Mixer?

An analog mixer is an audio console where the signal flow is processed continuously through physical circuitry (wires, resistors, and potentiometers) rather than being converted into digital data.

• "Unpowered" Defined: These mixers do not have built-in power amplifiers. They must be connected to powered speakers (active) or an external power amplifier connected to passive speakers to produce sound.
  • They are sometimes called passive mixers, but that is a misnomer. Real passive mixers do not have power supplies. This guide doesn't cover passive mixers.
• The "Analog" Appeal: Unlike digital mixers that use menus and screens, analog mixers generally offer "one knob per function." This provides immediate tactile control and zero latency (no processing delay), making them highly reliable and intuitive for live performance.

2. Main Features & What They Do

The "Channel Strip" is the vertical column of controls representing one input. Understanding one strip means understanding the majority of the board.

The Input Section (Top of the Strip)

• Mic Input (XLR): A balanced connection for microphones. It expects a weak signal that needs boosting.
• Line Input (1/4" TRS): For connecting keyboards, drum machines, or playback devices.
• Hi-Z / Instrument Input: A specialized input (often on the first few channels) that allows electric guitars or basses to be plugged in directly without a Direct Box (DI), preserving their tone.
• Gain / Trim: This is not a volume knob. It adjusts the input sensitivity to boost a weak microphone signal to a working level (Line Level) before it enters the rest of the mixer.
• Phantom Power (+48V): A switch (often global) that sends electrical voltage down the XLR cable to power condenser microphones or active DI boxes.
• Low Cut / HPF (High-Pass Filter): A button that cuts off low frequencies (usually below 80-100Hz). It removes stage rumble, microphone handling noise, and vocal "pops" without affecting the main sound.

The Insert Point

• What it is: A 1/4" TRS jack that acts as both an input and an output simultaneously.
• What it does: It creates a signal loop to "insert" external hardware (like a compressor or outboard EQ) directly into that specific channel's path.

Equalization (EQ)

• What it does: Shapes the tone by boosting or cutting specific frequencies.
• Fixed EQ: Standard High (Treble), Mid, and Low (Bass) knobs fixed at specific frequencies.
• Swept-Mid EQ: Found on intermediate/pro boards. It features two knobs for the mid-range: one to pick the specific frequency (e.g., finding a "honky" vocal frequency) and one to cut or boost it. This is a massive selling point for fixing problem sounds.

Aux Sends (Auxiliaries)

• What they do: These knobs split the signal to send a separate mix to a different location, independent of the main speakers.
• Pre-Fader (Monitors): The signal is sent before it hits the bottom volume fader. If the engineer changes the house volume, the band's monitor volume remains unchanged. Essential for stage monitors.
• Post-Fader (Effects): The signal is sent after the fader. If you turn down the vocal fader, the reverb on that vocal turns down with it. Essential for FX units.

Output & Dynamics

• One-Knob Compression: Found on many modern analog boards (like Yamaha MG series or Mackie ProFX). It simplifies complex dynamics processing into a single knob that evens out volume spikes (e.g., whispering vs. screaming).
• Pan: Places the sound in the left or right stereo field.
• Mute / On: Silences the channel instantly.
• PFL (Pre-Fader Listen) / Solo: Sends that specific channel's audio to the engineer's headphones and the main LED meters, allowing them to check levels/quality without affecting the audience's mix.

Fader: The slider at the bottom that controls the final volume of that channel going to the main mix.