ELECTRO HARMONIX Q-Tron Plus

ELECTRO-HARMONIX Q-Tron+ Envelope Filter with Effects Loop

Electro-Harmonix Q-Tron+ is the most powerful dynamic filter ("auto-wah") in the EHX series, offering studio-quality sound and unique signal routing capabilities. This pedal is based on the original 70s "Mu-Tron III" design (created by Mike Beigel) but enhanced with an innovative Effects Loop feature.

The effects loop (Send/Return) in this pedal is unique because it is inserted between the preamplifier and the filter section. This means that the dynamic detector responds to your clean, direct playing (attack), even if you plug a strong fuzz, distortion, or modulation effect into the loop. The result is that the filter is perfectly controlled by your finger dynamics, but it filters an already distorted sound, which would be impossible with ordinary pedals.

The pedal offers a wide range of sounds: from a gentle "bubble" to a sharp, screaming funk tone. The Response switch allows you to select the reaction speed (Fast/Slow), and the Range switch - the frequency range (Hi/Lo). The four-position Mode switch (LP, BP, HP, Mix) allows you to choose which frequencies the filter will pass, providing complete tonal control.

Key Features

• Effects Loop: Integrated loop allows inserting effects before the filter without losing dynamic control.
• 4 Filter Modes:
  • LP (Low Pass): Emphasizes low frequencies.
  • BP (Band Pass): Emphasizes mid frequencies (classic "wah").
  • HP (High Pass): Emphasizes high frequencies.
  • Mix: Mixes the BP filter with the clean signal.
• Response Switch: Changes attack speed (Fast – for percussive playing, Slow – for smooth, vocal sound).
• Range Switch: Hi (for high frequencies / solo) and Lo (for rhythm / bass) settings.
• Gain and Peak Control: Gain sets the filter sensitivity, Peak – the sharpness of the resonance ("Q").
• Overload LED: Indicator warning of an overly strong signal to avoid unwanted distortion.
• True Bypass: When the effect is off, the signal bypasses the circuit unchanged.

Technical Specifications

• Manufacturer: Electro-Harmonix (EHX)
• Model: Q-Tron+
• Type: Envelope Filter with FX Loop
• Circuitry: Analog
• Bypass: True Bypass
• Connections:
  • 1 x Input (1/4" female)
  • 1 x Output (1/4" female)
  • 1 x FX Send (1/4" female)
  • 1 x FX Return (1/4" female)
• Power: 24VDC-100mA adapter (included). Attention: Do not use standard 9V adapters.
• Dimensions: 146 x 121 x 64 mm

What's in the box?

• 1 x Electro-Harmonix Q-Tron+ pedal
• 1 x 24VDC-100mA power supply
• 1 x User manual

Intended for?

• Experimenters who want to combine auto-wah with fuzz or distortion pedals.
• Funk, Fusion, and Rock guitarists looking for an authentic Jerry Garcia or Bootsy Collins style sound.
• Musicians who need maximum dynamic filter control in the studio.