The kittycasterFX Tremdriver is a preamp pedal with a foot-switchable harmonic tremolo, built in the USA and launched in April 2022 at $3991. It pairs a JFET preamp running internally at 24 volts with a harmonic tremolo whose LFO circuit is derived from the one found in a Uni-Vibe21. kittycasterFX promises it will "to make any rig sound bigger and better"1.
Where a vintage EP-3 Echoplex preamp used a single preamp JFET stage, the Tremdriver gives you three discrete JFET preamp stages in a series/parallel configuration2. Delicious Audio describes it as a high-headroom preamp plus harmonic tremolo combo, built from vintage all-discrete circuit blocks and designed to sound like the classic '70s big wall-powered preamps3.
A JFET preamp with harmonic tremolo
The Tremdriver's preamp side employs three EP-3-style JFET preamps running at 24 volts, combined from vintage all-discrete circuit blocks and voiced to recall the big wall-powered preamps of the '70s3. Guitar World's reviewer, Trevor Curwen, notes the comparison with the Echoplex: "where the EP-3 featured a single preamp JFET stage, here you get three discrete JFET preamp stages in a series/parallel" configuration2.
The tremolo side is a harmonic tremolo, the kind that pans the signal between two frequency bands rather than chopping the whole signal up and down. When the LFO footswitch is engaged, the signal starts panning between the treble and bass JFET stages to give the harmonic tremolo sound2. The LFO circuit itself has a vintage connection: it was derived from the one found in a Uni-Vibe2. Delicious Audio calls the result "amazingly lush and swirly pulses"3.
A point that matters for how you use it: the tremolo only works if the preamp is active2. The two functions are switched separately, so the preamp can run on its own as an always-on stage.
The controls and modes
| Control | What it does |
|---|---|
| Drive | Splits the signal to two parallel JFET preamp stages voiced treble and bass2 |
| Output | Sets the level; with Drive, "puts you in clean boost heaven"3 |
| Speed | Adjusts the harmonic tremolo speed "from a slow pulse to a quick quiver"3 |
| Preamp footswitch | Engages the preamp2 |
| LFO footswitch | Kicks in the harmonic tremolo; works only with the preamp active2 |
The Drive control is the heart of the preamp's character: it splits out the signal to two parallel JFET preamp stages that are voiced treble and bass2. Delicious Audio suggests that working the Drive and Output controls together "puts you in clean boost heaven"3, which fits the maker's positioning of the pedal as a rig-wide tonebuilder rather than a dirt box. For players comparing it with gain pedals, it sits closer to preamp and boost territory than to overdrive or distortion.
Power: 9V in, 24V inside
The Tremdriver runs from a standard 9V DC adaptor, which is not supplied, drawing 70mA2. Inside, it converts that 9V to 24 volts2. That internal step-up is what gives the preamp its high headroom: Guitar World describes it as "a high-headroom preamp that runs from a standard nine-volt supply but internally converts it to 24 volts"2. Delicious Audio confirms it runs off a standard 9-volt power supply3.
The power supply is not included with the pedal, so plan on a 9V DC adaptor with at least 70mA of available current2.
Enclosure, size and build
The Tremdriver comes in a pedalboard-friendly custom enclosure3. Guitar World's review describes it as "a pretty damn solid wedge-shaped, two-part sheet aluminium chassis and psychedelic-style graphics"2. Connections sit on the front, and the base carries four rubber feet, with supplied countersunk screws that allow a flush base for Velcro mounting2.
Build quality earned a specific verdict from the reviewer: "Excellent build quality" was listed among the pedal's plus points2. The pedal measures 86 (w) x 139 (d) x 75mm (h)2.
Where it goes on a pedalboard
Both press sources agree on placement. The recommended position is near the end of the signal chain, but before reverb and delay21, where it can interact closely with your amp3. Guitar World frames it as acting like the master fader for the whole pedalboard, working as an always-on tonebuilder2. Delicious Audio sums up the idea: "It's like a mastering plug-in for your pedalboard!"3.
Who makes kittycasterFX pedals
kittycasterFX pedals are built by Jean Mastaler and her small team in Portland, Oregon3. The company's line includes the Tremdriver, a preamp/harmonic tremolo pedal priced at $399 and made in the USA1, alongside another pedal with a similar layout and structure, the Groovy Wizard Fuzz Driver3.
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Questions
Is the kittycasterFX Tremdriver true bypass?
Yes. Guitar World's review lists true bypass among the pedal's features. The preamp and tremolo sections are engaged with their own footswitches, and the tremolo only works when the preamp is active.
Where does the Tremdriver go on a pedalboard?
The recommended position is near the end of the signal chain, but before reverb and delay, so it can interact closely with your amp. Guitar World describes it as acting like the master fader for the whole pedalboard, working as an always-on tonebuilder.
Can the Tremdriver be used as a preamp without the tremolo?
Yes. The preamp and the harmonic tremolo are switched separately, and the tremolo only works if the preamp is active. With the tremolo off, the Drive and Output controls alone put you in what Delicious Audio calls clean boost heaven.
How much does the kittycasterFX Tremdriver cost?
The Tremdriver launched at $399 in April 2022, and Guitar World's later review still lists the price as $399. It is built in the USA.
Who makes kittycasterFX pedals?
kittycasterFX was formed in July 2020 by Howard Gee, a former Catalinbread designer, with a founding team including Scott Miller, Steve Hamari, Boris Lutskovsky and Jean Mastaler. The pedals are built by Jean Mastaler and a small team in Portland, Oregon.
Sources (3)
- Howard Gee's kittycasterFX makes its debut with Tremdriver preamp/harmonic tremolo and Groovy Wizard fuzz pedals, Guitar World, 2022-04-14
- KittycasterFX Tremdriver and Groovy Wizard review, Guitar World, 2023-01-11
- Kittycaster FX Tremdriver, Delicious Audio, 2022-08-21
