Use an Expression Pedal as Wah or Volume with Spark Control X – Help Center

An expression pedal plugged into Spark Control X lets you control Spark app parameters hands-free with your foot.

What you can do with it:

Wah - sweep classic wah effects in real time.
Guitar Volume - swell or duck your guitar without touching the amp knobs.
Music Volume - independently ride backing track volume (Spark 2, Spark EDGE, Spark LIVE).

Spark Control X has two 1/4" TRS jacks, so you can hook up two expression pedals at once and assign a different function to each.

Set Up Your Expression Pedal

You'll need a standard TRS expression pedal (sold separately).

Not every "pedal" works here. An expression pedal is different from a wah or volume pedal - if yours isn't responding, jump to If Your Pedal Isn't Responding.

Step 1: Pair Spark Control X with your amp

Before assigning functions, make sure Spark Control X is already paired with your Spark amp. Follow the guide for your model:

Step 2: Plug in your expression pedal

Use a TRS cable and plug into either expression pedal jack on Spark Control X.

TRS (Tip-Ring-Sleeve) connector diagram

Step 3: Open the Footswitch Menu

On the Tone Page in the Spark app, tap the icon to the left of the ToneCloud icon.

Tone Page with Control icon to access Footswitch Menu

Step 4: Assign a function

Tap Exp Pedal, then choose what you want the pedal to control.

Assign expression pedal in the Footswitch Menu

Pick Wah Pedal LFO or Volume Control:

To use it as a wah: after assigning Wah Pedal LFO, double-tap the COMP/WAH effect in the Spark app and pick Auto Wah (or J.H. Legendary Wah if you own the Experience Jimi Hendrix expansion pack).

Spark app COMP/WAH picker showing Auto Wah and J.H. Legendary Wah

Guitar Volume behavior: The pedal controls the GUITAR knob on your amp. There's no threshold - fully pressed = maximum. Use the amp's MASTER knob to cap the top volume.

Battery note: Connecting an expression pedal drains the Spark Control X battery faster - even in standby.

If Your Pedal Isn't Responding

Are you plugging in a wah pedal or a volume pedal? That's the most common reason - and it won't work with Spark Control X.

Wah pedals and volume pedals process your guitar signal directly - they have to sit in the audio path. Spark Control X doesn't route audio; it sends Bluetooth control commands to the Spark app. So any pedal that needs to touch the actual audio signal won't work here.

What works instead: an expression pedal. It sends a control signal (not audio) that the Spark app uses to adjust digital parameters like wah, volume, or other assignable functions.

What to look for when shopping

TRS (Tip-Ring-Sleeve) connection
No built-in audio processing - it must be a passive expression pedal, not a wah or volume pedal

Known compatible models: Mission Engineering EP-1, Moog EP-3, Roland EV-5, Boss FV-500, M-Audio EX-P. Ask your music shop to confirm before buying.

FAQ

Q: What does the expression pedal control by default?

A: Guitar Volume. Change it in the Spark app's Footswitch Menu.

Q: Can I connect two expression pedals at once?

A: Yes - Spark Control X has two jacks. Assign a different function to each.

Q: Does the expression pedal affect battery life?

A: Yes. Battery drain increases while a pedal is connected, both in standby and when powered on.