The Vahlbruch Kaluna is a tube overdrive and distortion pedal from German maker Vahlbruch, first announced in June 2020. Its whole reason for being is voltage: most tube pedals run their valve at a fraction of its design voltage, but the Kaluna runs its ECC83/12AX7 double triode at a full 250 volts, generated inside the pedal from an ordinary 9V supply12. The maker's pitch is that this high voltage produces a tone more saturated with overtones while keeping the responsive feel and clarity that tube amp preamps are known for3.
The circuit is 100% analog and built around that single 250-volt ECC83/12AX7 tube23. Vahlbruch says it delivers a wide range of distortion characteristics, from mild breakup to creamy saturation, with an open, transparent sound and a wide dynamic range2. Delicious Audio describes the result as sweet harmonic content, overdrive clarity, fast pick attack response and a complex compression similar to a cranked tube amp4.
How it works: a real tube voltage from a 9V supply
The key idea is that the high voltage a 12AX7 wants in an amplifier is created inside the pedal from the standard 9V power line14. Premier Guitar noted at launch that the high voltage required for this type of tube circuit is generated internally from the standard 9V supply, so no special high-voltage power brick is needed2. Guitar.com reported that this high voltage level is generated from a standard 9-volt power jack3.
That said, the pedal is not light on current. It draws 500mA at 9V12, which rules out a typical low-current daisy chain position and means the supply must be rated for at least 500mA. Guitar Player confirmed that any standard nine-volt unit with a minimum output of 500mA will work, connecting through a 2.1mm jack, with the supply not included6.
The Kaluna II adds an overvoltage protection circuit that prevents damage to the tube if a power supply with more than 9V is accidentally connected14. The original Kaluna has no such protection, so only a 9V supply should be used with it.
The controls: Volume, Drive and a three-band EQ
The control set is deliberately amp-like. Pete Thorn, demoing the Kaluna II on his YouTube channel, summed it up as "You get a drive control, volume control, and threeband EQ, much like the controls that you would find on an amplifier"7.
| Control | What it does |
|---|---|
| Volume | Sets the output level5 |
| Drive | Sets the amount of gain and breakup71 |
| Bass, Middle, Treble | Active three-band EQ placed after the tube in the circuit, each with up to 12dB of cut and boost18 |
The EQ sits post-tube, which Premier Guitar described at launch as a flexible active three-band tone control placed after the tube inside the circuit, letting you match the pedal's sound spectrum to your guitar, effects chain and amp2. Guitar World's reviewer called it a powerful three-band EQ offering plenty of shaping range8.
The EQ also unlocks a second use. Guitar World found that with Drive at minimum, the Volume knob gives a decent cleanish boost in about the last third of its range, so the pedal can pull boost pedal duty8. Pete Thorn made a similar point about the Kaluna II:
"that sounds like a nice, you know, mod, nice boost to put in the front of the amp, except it's pedal that you can just order online without having to open up your amp"
MagTraB switching and power-up bypass mode
Instead of a mechanical footswitch, the Kaluna uses Vahlbruch's own MagTraB design. A magnet is integrated into the head of the switch pole, and a sensor inside the pedal detects its position when you move the switch. A micro-controller reads that movement and triggers a gold-plated relay that does the actual audio switching, so there is no mechanical contact in the signal path24.
The pedal also has a programmable power-up mode. In only four steps you can choose whether it powers up in true bypass or in on mode, and the setting is stored, so after a power cut the pedal returns to whichever state you prefer14.
What is different on the Kaluna II?
In late 2024 Vahlbruch released an upgraded version, the Kaluna II, which keeps the original's tube circuit and control set and adds two things45:
- A three-way Structure switch: V1 reproduces the familiar gain structure of the first version, Hot is a higher gain mode, and Low runs at lower gain17
- An overvoltage protection circuit that safeguards the tube if a supply above 9V is connected14
Guitar Pedal X reported the Kaluna II available to order from the Vahlbruch Effects webstore and at selected international dealers5. Pete Thorn's video demo covers the Structure switch positions, including Hot as the higher gain mode7.
What reviewers said
Guitar Player's Art Thompson reviewed the pedal with a Les Paul Historic '59, a Fender American Pro II Strat and a Reverend Greg Koch Gristlemaster, through a Fender Deluxe Reverb and a Mesa/Boogie Mark Five: 25 1x10 combo, and summarized it as a dynamic tube overdrive with a flexible 3-band EQ, at $372 direct6. He also noted the build: a metallic-gold aluminum enclosure measuring roughly 4.5 by 3.5 inches, black retro-style knobs, and slots for venting heat from the tube6.
Guitar World's review listed the Kaluna at £295 and highlighted the same strengths, the valve-based overdrive running from a nine-volt supply and the powerful three-band EQ8.
Pete Thorn's demo of the Kaluna II walks through the Structure switch settings and the boost use case75:
Videos
Pete Thorn
Shawn Tubbs
EytschPi42
Questions
Does the Vahlbruch Kaluna need a special power supply?
No. It runs from a standard regulated 9V supply, but it draws 500mA, so the supply must be rated for at least that. The 250 volts the tube needs is generated inside the pedal from the 9V input. The Kaluna II adds an overvoltage protection circuit that prevents tube damage if a supply above 9V is connected.
Can the Kaluna be used as a clean boost?
Yes. Guitar World's reviewer found that with Drive at minimum, the Volume knob gives a decent cleanish boost in about the last third of its range. Pete Thorn also described it as working like a boost in front of an amp, without having to modify the amp itself.
Where is the Vahlbruch Kaluna made?
It is handmade in Germany by Vahlbruch, a company based in Springe, Germany. The pedal is the brainchild of Dr. Henning Vahlbruch, according to Guitar Player's review.
What is different on the Kaluna II?
The Kaluna II adds a three-way Structure switch with V1, Hot and Low positions. V1 keeps the gain structure of the original, Hot is a higher gain mode and Low runs at lower gain. It also adds an overvoltage protection circuit for the tube.
Is the Vahlbruch Kaluna true bypass?
Yes. It uses Vahlbruch's MagTraB relay switching, and you can program it in four steps to power up either in true bypass mode or in on mode, so it returns to your preferred state after a power loss.
Sources (8)
- Vahlbruch, Vahlbruch FX, 2025
- Vahlbruch FX Presents the Kaluna, Premier Guitar, 2020-06-18
- Vahlbruch Effects launches the tube-powered Kaluna overdrive, Guitar.com, 2020-06-22
- Vahlbruch Kaluna II Tube Overdrive, Delicious Audio, 2024-12-24
- Guitar Pedal X, Guitar Pedal X, 2024-11-28
- Vahlbuch Kaluna High Voltage Tube Drive Review, GuitarPlayer (www.guitarplayer.com), 2021-01-14
- AWESOME REAL TUBE DRIVE AND ANALOG DELAY TONES! Vahlbruch Kahluna II and Spacetime Tap V2, YouTube (Pete Thorn channel), 2025-05-27
- Vahlbruch Kaluna Tube Overdrive, SpaceTime Tap & Quantum Compressor review, Guitar World, 2020-08-25
