GFI System Specular Tempus

The GFI System Specular Tempus is a stereo delay and reverb pedal in one compact box. GFI describes it as "a powerful reverb and delay effect processor in a compact pedal," with 32 hand-crafted algorithms, 32 presets, stereo input and output, tap tempo and what the maker calls extensive inter-connectivity¹. It launched in October 2017, combining the circuits of two earlier GFI pedals, the Clockworks Delay and the Specular Reverb, into a single freely programmable unit².

The pedal has since been replaced in GFI's line by the Solis Ventus, a larger dual-engine workstation launched in December 2024³. GFI still lists the Specular Tempus on its site at USD 349.00 and continues to host its firmware documentation¹.

A reverb and delay in one compact pedal

The Specular Tempus sits in a horizontal case slightly bigger than a Boss compact pedal, with four knobs giving instant access to the most commonly used controls⁶. It grew out of two earlier GFI pedals: Gearnews reported at launch that the manufacturer had combined its Clockworks Delay and Specular Reverb into one unit². Delicious Audio described it as an expanded, more powerful version of the well-received Specular Reverb⁶.

The algorithm count differs between accounts. GFI's product page lists 32 hand-crafted algorithms¹, and Delicious Audio's 2024 ambient and shoegaze buying guide breaks that down as 13 delays, 13 reverbs and 6 delay-plus-reverb combinations⁷. Earlier press counted more: Pedal of the Day's 2019 review said "the 36 algorithms are made up of 13 Reverbs, 17 Delay and 8 Combination settings"⁴, and Guitar Pedal X's 2021 roundup also listed 36 algorithms, 16 reverbs plus 20 delays⁸. The maker's current figure is 32.

GFI says the pedal covers a wide range of sounds, from standard to extreme, going through shimmer and endless sounds². The architecture is a single engine: GFI's own comparison table shows the Specular Tempus does not run two algorithms simultaneously and has no routing options, where the dual-engine Solis Ventus offers series, parallel and dual mono routing¹. It does have analog dry thru and spillover, so your dry signal stays analog and effect tails continue when you bypass¹. There is no built-in looper¹.

The controls and footswitches

The pedal has two footswitches, labeled A and B, each with an LED⁹. The 32 presets are organized in 4 pages, where each page contains 4 banks, and each bank contains 2 patches: A and B¹. Delicious Audio explains that the algorithms can be combined in two different banks triggered by the two footswitches, so you can set up two sounds and jump between them⁶.

The Auto Knob Swell function is a momentary effect activated by pressing both footswitches at once: it sweeps one knob's parameter to maximum, holds it there, then sweeps back when you release⁶. On That Pedal Show's 2017 video, Dan and Mick walked through the pedal's presets, including one called Funk Time, and noted the tap tempo control¹¹.

Power and connections: MIDI, Aux and effects loop

The Specular Tempus runs on 9V DC with a negative-center plug, drawing around 100 mA, and the power supply is not included¹. Input and output are 1/4 inch TS jacks, with 1 MOhm input impedance and 500 Ohm output impedance, and the converters run at 24 bits¹. It is compatible with instrument level only, not line level¹.

Beyond audio, GFI highlights four expansion interfaces: Aux-In, Aux-Out, Effects Loop and MIDI In¹.

• Aux-In accepts single, dual or triple button switch boxes for external control such as tap tempo and bank up/down⁶.
• Aux-Out provides a switch contact you can use to control other gear, for example switching an amp's channel⁶.
• Effects Loop uses 1/8 inch TS or TRS jacks and lets you insert other effects into the delay or reverb feedback path, creating your own unique delay or reverb sounds¹⁶.
• MIDI In opens nearly all functions of the pedal to MIDI access, including tap-tempo and expression pedal control⁶.

For external switching, American Loopers makes an external aux switch with two clickless switches that works with the Specular Tempus and can be programmed to many of its functions¹². Pedal of the Day's reviewer went further, saying it is "MUCH easier if you splurge and get the optional Triple Switch," which plugs into the Aux jack and provides bank up and down, page-up, tap tempo, favorite preset select, auto-swell, momentary A and B, and warp-dotted, warp-half or warp-triplets choices⁴.

Where it came from and what reviewers said

GFI System is an Indonesian manufacturer, and the Specular Tempus is one of its digital effect devices. Gearnews noted at the launch that the Indonesian manufacturer had caused a bit of a sensation in the pedal business with its digital effect devices². GFI says the Specular Tempus can cover a wide range of sounds, from standard to extreme, going through shimmer and endless sounds².

Reviews were positive. Delicious Audio called it "an impressive pedal for players with ambient/experimental leanings" and added it to the site's Best Ambient/Shoegazer Pedals list⁶. The same review noted the horizontal case is slightly bigger than a Boss compact pedal, with four knobs giving instant access to the most commonly used controls⁶.

GFI publishes a user manual for the Specular Tempus, with version v3.8 available as a PDF from the maker's site⁹. Reviewers have advised players to read the manual to get the most from the pedal⁴.

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