The Poly Effects Flat V is a touch-screen, dual-channel gain pedal from Poly Effects. Poly describes it plainly: "Flat V is a gain pedal with 2 channels"1.
What it does
The Flat V is built around two overdrive channels that can be used separately or stacked. MusicRadar's Jonathan Horsley described it as "two channel beast, with dual-footswitches, and the capability of swapping the order the channels stack"3, so either channel can feed the other depending on which gain structure you want.
| Feature | What it gives you |
|---|---|
| Two channels | Separate drives, usable alone or stacked3 |
| Swappable stack order | Either channel can feed the other3 |
| Four diode options | Clipping choices that shape each channel's character2 |
| Auto-wah and tremolo | Built-in effects beyond the gain stages3 |
| MIDI-switchable presets | Preset recall from a MIDI rig4 |
Beyond the two drives, Horsley noted that "you can also throw your tone off course with auto-wah and tremolo"3, making it part overdrive and part multi-effect, though its core brief is gain.
Poly also highlights a blending feature: "You can blend with the waveshapes, MIDI or an envelope that reacts to your playing"1. In practice that means the mix between the two channels can be shaped dynamically or controlled externally rather than only by a static knob setting.
The pedal carries four diode options, the clipping choices that shape the character of each channel2.
Those same four diode options later became the basis of Poly's Kanso, a standalone diode overdrive the company extracted from the Flat V's Diodes A channel in a slightly different arrangement2.
Controls and MIDI
The front panel uses touch sliders on the screen rather than physical knobs. The controls work like this:
- Touch sliders on the screen set the main parameters3.
- Pressing any secondary function button places all the sliders into secondary function mode, so one press shifts the whole control surface to a second set of parameters3.
- Dual footswitches handle the two channels3.
For players running a MIDI rig, the pedal has MIDI-switchable presets. On That Pedal Show, Mick Taylor explained the design brief: "Josh wanted an overdrive pedal to cover all his gain needs, including MIDI switchability"4. The published MIDI CC map assigns CC 1 to Blend Override, where a value of 0 to 127 sets the A to B blend, intended for an expression pedal or a mod wheel5.
Where it came from
Poly Effects announced the Flat V on 17 January 2023 as a signature pedal with Josh Smith3, and it was shipping by March of that year4. Guitar Pedal X's Stefan Karlsson later called it "Josh Smith's Touch-Screen Signature Flat V Dual-Channel Overdrive Collaboration with Poly Effects"2, and the pedal's diode circuitry has since spawned the Kanso standalone diode overdrive2.
Videos
Andertons Music Co
R.J. Ronquillo
Josh Smith (Guitarzan)
Questions
Can the Flat V's two channels be used at the same time?
Yes. MusicRadar describes the Flat V as a two-channel pedal with dual footswitches, and the channels can stack into one another, with the order of the stack swappable. That means you can run one channel into the other for more gain, and choose which channel comes first.
Does the Flat V work with MIDI?
Yes. The pedal has MIDI-switchable presets, which was part of Josh Smith's brief for the design, according to That Pedal Show. A MIDI CC map also assigns CC 1 to a Blend Override function, where a value of 0 to 127 sets the A to B blend, intended for an expression pedal or a mod wheel.
Sources (5)
- Josh Smith Flat V, Poly Effects
- Guitar Pedal X, Guitar Pedal X, 2026-01-14
- Josh Smith teams up with Poly Effects for the Flat V, a two-channel overdrive like you've never seen before, MusicRadar, 2023-01-17
- The Ultimate Do-It-All Overdrive? Poly Flat V, Kernom Ridge, CB Automatone Preamp MkII, That Pedal Show (YouTube), 2023-03-10
- Voes | MIDI-CC, Voes, 2024
