The GFI System Rossie is a dynamic multi-filter pedal that packs three filter effects into one compact box: an envelope filter that responds to your picking, a step filter that creates groovy arpeggiated patterns, and a manual filter you control yourself1. Each of the three modes offers the same four classic filter shapes, lowpass, bandpass, highpass and peaking, so you can shape the effect to sit anywhere in your tone1. It is a digital pedal, which is worth noting in a category that, as Delicious Audio's Paolo De Gregorio observed, "more than any other hangs on to its analog origins"2.
The Rossie arrived as GFI System's newest release in February 20242. It lists at USD 249.001.
Three modes and four filter shapes
The Rossie's circuit offers three modes, and each one works differently2:
| Mode | What it does |
|---|---|
| Envelope Filter | A colorful resonant filter that follows your picking dynamics12 |
| Step Filter | Creates groovy arpeggiated filter patterns1 |
| Manual Filter | Filter control by hand or by expression pedal12 |
Within any mode you choose one of four filter types: lowpass, bandpass, highpass, or peaking1. A lowpass shape sweeps from bright to dark, a bandpass isolates a moving band of frequencies, a highpass thins the sound from full to thin, and a peaking shape boosts a narrow band rather than removing anything. Sweep range and resonance width are also adjustable, so you control how far the filter travels and how sharp its peak is1.
A dedicated Mix knob blends the wet and dry signal1, which lets you keep some of your original guitar tone under the filtered sound, a useful option on an effect that can get as extreme as a resonant filter at full sweep.
A small display shows the parameters' levels and the chosen mode2, so you can see where the controls sit without guessing.
Footswitches, presets and expression control
The Rossie carries two footswitches. The On/Off switch does double duty: press it to bypass the effect, and hold it down to trigger a momentary ramp effect2. The filter sweeps only while the switch is held, then lets go when you release it, which works for quick accents and transitions.
The pedal stores two presets2, enough for a pair of contrasting settings but far fewer than a multi-effects unit holds.
The expression pedal input allows wah wah action as well as control of other parameters2. Plugging in an expression pedal turns the Rossie's manual filter into something close to a wah pedal, with your foot sweeping the filter instead of your picking dynamics driving it.
Power and connections
The Rossie runs on 9V DC with a negative center pin, and the power supply is not included1. Current consumption is about 110 mA1, which is modest by digital pedal standards but rules out a battery, and it is worth checking that a small daisy chain can deliver enough current for it alongside other digital pedals.
The Rossie is mono: one input, one output2. Players running stereo rigs will need to place it before a split or accept a mono filter in the chain.
Its input impedance is 1 MOhm and its output impedance is 1K Ohm1, figures that mean it plays nicely with both passive pickups and the inputs that follow it. The enclosure measures 12 (L) x 7.2 (W) x 5.5 (H) cm and weighs 0.6 Kg (1.6 lbs)1, a compact footprint for a pedalboard.
GFI System publishes an English user manual for the Rossie, dated January 19, 2023, available as a download from the maker's site3.
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Questions
Is the GFI System Rossie analog or digital?
It is digital. Delicious Audio describes the Rossie as a digital, dynamic multi-filter pedal, which is notable because filter effects more than most have historically stayed analog. Its converters run at 24-bit resolution according to GFI System's specifications.
Is the Rossie stereo?
No. The Rossie has a mono input and a mono output, so it is a mono pedal throughout. Players building stereo boards will need to look elsewhere for a filter with two outputs.
How many presets does the Rossie store?
It stores two presets. That is enough to keep one sound for verses and another for choruses, but players who want a large library of filter settings will find it limited compared with bigger multi-effects units.
Can I use an expression pedal as a wah with the Rossie?
Yes. The Rossie has an expression pedal input that allows wah wah action as well as control of other parameters, so plugging in an expression pedal gives you manual filter control much like a traditional wah, without the foot rocking.
What does holding the Rossie's on/off switch do?
Holding down the On/Off footswitch acts as a momentary ramp effect. The filter sweeps only while you keep the switch held, then returns when you release it, which is handy for quick accents and transitions.
Sources (3)
- Rossie Filter, GFI System
- GFI System Rossie Multi Filter, Delicious Audio, 2024-02-05
- GFI System, GFI System, 2023-01-19
