The Guyatone Ultron is an envelope filter pedal that works as an auto-wah or manual-wah, tracking how hard you play and sweeping a filter in response. Premier Guitar reviewed it as the "Ultron Hybrid Optical Envelope Filter," and MusicRadar reviewed it under its full model name, the Guyatone GST-UO5 Ultron.12
What it does
The Ultron's circuitry is based on the Mu-Tron III envelope filter of the 1970s. MusicRadar describes the GST-UO5 as offering three main types of envelope filtering, and Premier Guitar notes that Guyatone based the optical circuitry on the "iconic Musitronics Mu-tron III," adding that "it shows."12
Like the Mu-Tron III, the pedal offers selectable high-pass, band-pass and low-pass filter types, so the swept filter can be shaped to emphasize different parts of the signal. The control layout matches Guyatone's related Ultrem pedal, with six Effects Modes and six selectable Wave Forms.1
Internal dip switches let the Ultron be fine-tuned for instruments beyond guitar, such as bass or keyboards.1
What reviewers said
Premier Guitar's reviewer was positive about how the filter responds and how quickly it can be set up1:
"It sounds so much more natural than any auto-wah I've played through in the past"
The same review found it easy to quickly dial in a great sound, and responsive enough to encourage ditching the pick, which speaks to how much playing dynamics shape the effect.1
Related Guyatone filters
Guyatone has a history in this corner of the filter world. The company's earlier WR-3 Wah Rocker was an envelope filter in its own right, and the FB-X Funky Box is another filter design from the brand. The Ultron sits alongside these as its optical, Mu-Tron III-based take on the auto-wah.12
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Questions
What is the Guyatone Ultron?
The Ultron is an envelope filter pedal from Guyatone that works as an auto-wah or manual-wah. Premier Guitar describes it as a hybrid optical design, with the filter circuitry based on the Musitronics Mu-Tron III of the 1970s. It provides selectable high-pass, band-pass and low-pass filter types, six effects modes and six wave forms, and internal dip switches to tailor it to instruments such as bass or keyboards.
How much does the Guyatone Ultron cost?
Premier Guitar's March 2021 review listed the Ultron at $425 USD. That was the price given at the time of the review, so current street prices may differ.
Sources (2)
- Guyatone Ultrem and Ultron Hybrid Optical Effects, Premier Guitar, 2007-06-12
- Guyatone GST-UO5 Ultron review, MusicRadar, 2007-12-10
