Detail 01
Lowpass filter mode
Sweeps below the cutoff, cutting highs. This is the classic thick funk quack most players reach for.
Product detailSKU #1274034486405
Electro-HarmonixXO Q-Tron Plus Envelope Filter Guitar Effects Pedal
funkrock
Independent shopping perspective
The Korena take
Envelope filter for guitar or bass, around $190. For players who want auto-wah quack on funk rhythm parts or moving filter textures in rock.
Strong match
Who this is for
- Funk rhythm playing where picking hand drives the filter sweep
- Rock leads that need a vocal, talkbox-adjacent midrange sweep
- Bass players chasing synth-style movement without a synth pedal
Consider the trade-offs
When to look elsewhere
- Players wanting a fixed wah pedal with a treadle
- Light pickers — weak attack barely opens the filter
- Anyone needing an always-on subtle tone shape
What matters in use
The specifications, translated
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 02
Bandpass filter mode
Passes a narrow band and drops both ends. Nasal, vocal, sits forward in a band mix.
Detail 03
Highpass filter mode
Keeps the top and thins the low end. Bright, glassy sweeps that stay out of a bassist's way.
Detail 04
Bandpass mixed with dry signal
Keeps your unprocessed tone under the filter, so the effect adds movement without gutting body or note definition.
Detail 05
Up or down sweep direction
Up opens as you dig in, the familiar wah-forward sound. Down closes on attack, giving backwards, sucking swells.
Final check
Know before you order
- 01Set the sensitivity to your pickups and pick attack before judging the sound
- 02Plan board space and a free power output before ordering
- 03Envelope filters react to input level; a boost in front changes everything
Product questions
Before you decide
Straight answers to the questions shoppers most often ask about this product.
01Is this the same as a wah pedal?
No. A wah sweeps when you rock a treadle. This sweeps automatically from how hard you play, so both hands stay on the guitar.
02Does it work on bass?
Yes. Envelope filters are a bass staple, and the lowpass mode plus the dry blend option keep the low end from disappearing.
03Why does it barely do anything sometimes?
Input level. Low-output pickups or a light touch won't push the envelope enough. Raise the sensitivity or hit the strings harder.
04What's the point of the down sweep?
It closes the filter on attack instead of opening it, which sounds reversed and synth-like. Good for a change of texture on one section.
Reference
Full specifications
The complete catalog record, organized around the decisions musicians make when comparing gear.
1 detailsSound
- Select The Filter Used By The Effect
- Lowpass, Bandpass, Highpass or a mix of Bandpass with dry unprocessed sound.
1 detailsOther
- Selects Direction of Filter Sweep
- upwards or downwards.
