Electro-Harmonix Q-Tron Plus Envelope Filter Pedal

Envelope follower plus effects loop. Like the original with added Effects Loop and Attack Response Switch. The Effects Loop lets you place an additional effect between the Q-Tron 's preamp and filter section without changing the envelope drive. The added Response Switch selects between a slow, smooth, vowel-like attack and the fast, snaked response of the original Q-Tron.