The Tru-Fi Compact Ultra Tremolo is a tremolo pedal with a booster built in, made by Tru-Fi and housed in a mini, pedalboard friendly enclosure the maker calls PBF Pedalboard Friendly Size. It is a compact version of the Tru-Fi Ultra Tremolo from the company's Vintage series: Tru-Fi describes it as "the same as the Vintage series Ultra Tremolo," now in a smaller and modern enclosure, with a blinking LED added. The maker describes its sound as "fat, warm and huge, musical," and notes that "it even pulsed when you put gain into it almost Vibe like."1
Where the circuit came from
Tru-Fi's account of the pedal's origin starts in a pawn shop. "20 years ago, I was in a pawn shop in Brooklyn, NY," the maker writes, describing the find of the original Kent tremolo unit that became the basis for the design. The circuit itself, according to Tru-Fi, "is a take off of the Schaller Tremolo which branded them for the Kent guitar company 50 years ago." The maker announced the compact version as ready for sale 20 years after that original was found.1
Tremolo circuits of this general family work by using a Low Frequency Oscillator to modulate the volume of the signal. As Coda Effects explains in a technical analysis of tremolo design, such circuits "Use a Light Dependant Resistor (LDR) on the signal path, and a LED lit by the LFO," often combined in a vactrol, with the photocell either connected to ground or used to bias a tube, an IC or a FET transistor.2
Controls
The control set is simple, which the maker presents as part of the design's character: "The unit was basic, Depth, Speed and a Fast Slow switch."1
| Control | What it does |
|---|---|
| Depth | Sets tremolo depth; can be dialed to zero to use the pedal as a pure boost1 |
| Speed | Sets the speed of the tremolo pulse1 |
| Fast/Slow switch | Switches between fast and slow speed ranges1 |
The booster and using it as a boost
Alongside the tremolo, Tru-Fi added a booster stage: "I added a EP3 style booster to the front of it," the maker writes. Combined with the Depth control, this gives the pedal a second use. "You can EVEN dial Depth knob to Zero and just use it as a PURE BOOST," according to Tru-Fi, which makes it a candidate for players looking at boost pedals as well as tremolo pedals.1
The Compact Ultra Tremolo is the same circuit as the Vintage series Ultra Tremolo but in a smaller mini enclosure, and it adds a blinking LED. If you have room on the board, the Vintage series version is the full size alternative.1
Power
Tru-Fi states that "ALL mini pedals are 9v PS OR 9v Battery operated," so the Compact Ultra Tremolo runs on either a 9V power supply or a 9V battery.1
Videos
PJ and the Beard
Questions
Can the Tru-Fi Compact Ultra Tremolo be used as a clean boost?
Yes. Tru-Fi added an EP3 style booster to the front of the tremolo circuit, and the Depth knob can be dialed to zero, at which point the maker says you can use the pedal as a pure boost. That makes it a two-in-one pedal: tremolo when you want it, and a booster when the Depth control is off.
Does the Tru-Fi Compact Ultra Tremolo run on a 9V battery?
Yes. According to Tru-Fi, all of its mini pedals are 9V power supply or 9V battery operated, so the Compact Ultra Tremolo can run either way. That makes it easy to drop onto a pedalboard with a standard supply or to use without one.
How is the Compact Ultra Tremolo different from the Vintage series Ultra Tremolo?
Tru-Fi describes the Compact Ultra Tremolo as the same circuit as the Vintage series Ultra Tremolo, repackaged in a smaller, pedalboard friendly mini enclosure. The maker also added a blinking LED to the compact version.
What tremolo circuit is the Tru-Fi Ultra Tremolo based on?
Tru-Fi says the Ultra Tremolo is a take off of the Schaller Tremolo, which Schaller branded for the Kent guitar company about 50 years ago. The maker reports finding the original unit in a Brooklyn pawn shop 20 years before releasing the pedal.
Sources (2)
- NEW Compact Ultra Tremolo Guitar Pedal in smaller and modern enclosure, tru-fi.com
- Coda Effects, Coda Effects (www.coda-effects.com), 2016-05
