The Guyatone FB-X Funky Box is a tube-driven envelope-controlled filter, built to produce automatic wah and swept filter effects in a compact pedal format. It is the second offering in the Guyatone Flip Series of tube-powered floor-effects, meaning a real tube sits in the circuit rather than a simulation.1
Controls and wah modes
The FB-X gives the player two main controls over the envelope response:
Together they set how hard a picking attack triggers the filter and how quickly the sweep closes again.1
Beyond the envelope controls, the pedal offers switchable wah modes that allow the Funky Box to operate in multiple frequency bands. RockBoard's PedalPedia describes this as making the FB-X "perfect for use with an" extended range of instruments, and the multiple bands mean the same envelope response can be centered on guitar, bass, or keyboard ranges rather than one fixed band.1
Switching and status are handled electronically:
- Effect LED indicator, showing when the effect is engaged1
- Electronic silent switching, which the maker positions as making the FB-X ideal for live or studio performance1
How it tracks and sounds
The maker's own description is candid about the pedal's character:
"with its somewhat relaxed tracking and warm tube tone, the sounds that come out of the Funky Box are often unpredictable and never boring"
For a player, that suggests the FB-X is less a precision tool than a filter with personality, where the tube stage colors the sweep and the response leaves room for happy accidents1.
Power requirements
The FB-X needs 12V DC, center negative, and draws 160mA.1 Both figures are worth noting on a pedalboard: the voltage is above what many pedals share, and the current draw is high enough that a low-output supply position or a daisy chain may not run it reliably.
The FB-X runs on 12V DC at 160mA. Plan a dedicated supply output for it rather than sharing with other pedals.1
Where it sits in the Guyatone range
The FB-X belongs to the Flip Series, Guyatone's line of tube-powered floor-effects, and is the second offering in that series.1 Players looking at envelope filters from the same maker may also come across:
For the wider category, see Filter Pedals.
Questions
What power supply does the Guyatone FB-X Funky Box need?
The FB-X Funky Box runs on a 12V DC supply with a center negative plug. That is a higher voltage than many pedals use, so it may not share a supply with the rest of a board without a dedicated output. Check the supply requirements before wiring it into a daisy chain.
How much current does the FB-X Funky Box draw?
The FB-X Funky Box draws 160mA. That is well above the current many pedal power supplies provide on a single output, so a supply rated for higher current or a dedicated output is the practical choice for this pedal.
Is the Guyatone FB-X analog?
Yes. The FB-X Funky Box is an analog circuit, built around a tube as part of Guyatone's Flip Series of tube-powered floor effects.
Does the Funky Box use a real tube?
Yes. The FB-X is part of the Guyatone Flip Series of tube-powered floor-effects, so it uses a tube in its circuit rather than simulating one.
Is the Funky Box silent when switching?
Yes. The FB-X uses electronic silent switching, which the maker positions as making the pedal well suited to live and studio performance, alongside an Effect LED indicator that shows when the effect is engaged.
What is the Guyatone Flip Series?
The Flip Series is Guyatone's line of tube-powered floor-effects pedals. The FB-X Funky Box is the second offering in that series, pairing a tube circuit with a compact pedal format.
Sources (1)
- FB-X Funky Box by Guyatone, RockBoard PedalPedia, 2026
