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Vahlbruch Kaluna Tube Overdrive, SpaceTime Tap & Quantum Compressor review

Follow the science with these three Vahlbruch pedals, designed in Germany by a professor of physics

Vahlbruch Kaluna Tube Overdrive, SpaceTime Tap & Quantum Compressor review
(Image: © Future / Olly Curtis)

Our Verdict

With their premium build and clever switching, the Vahlbruch pedals are quality. The Kaluna and SpaceTimeTap are pricey but impressive sonically, while the Quantum is our favourite for its two-in-one practicality and always-on tone sweetening.

For

  • The Kaluna offers genuine tube drive and amp-like feel.
  • Kaluna's EQ section is powerful.
  • SpaceTimeTap has excellent tap tempo functionality.
  • Build is excellent throughout.
  • Quantum is a super-practical 2-4-1 buffer/compressor.

Against

  • Kaluna and SpaceTimeTap are pricey for the features.

Whoever said making stompboxes isn’t rocket science obviously hadn’t heard of Valbruch pedals, which are actually designed by a rocket scientist. 

Well, perhaps not a rocket scientist exactly, but Dr Henning Vahlbruch is professor of Gravitational Physics at the Albert Einstein Institute, and you don’t get a rocket off the ground without a deep knowledge of gravity…

Hand-built in Germany, the range currently comprises 13 different designs and features a unique switching technology designed by the prof. 

The Magnetic Transducer Button (MagTraB) switching works as follows: as you push the footswitch button the position of a magnet inside it is measured by a sensor; this sensor sends information via a micro-controller to a relay that does the actual switching.

The MagTraB system is said to be indestructible and capable of an almost infinite number of switching cycles, all with no mechanical switch clicks. Another feature is that you can set a pedal so that it powers up either on or bypassed – very practical for ‘always on’ pedals or any in switcher loops.

Vahlbruch High Voltage Tube Drive

(Image credit: Future / Olly Curtis)

The Kaluna is a valve-based overdrive that runs from a nine-volt supply, although you’ll need a 500mA output on your power distributor to get its ECC83/12AX7 glowing away through the grille. 

With Drive at minimum, the Volume knob will give you a decent cleanish boost in about the last third of its range, but the Drive knob is capable of many shades of drive through to saturation as it pushes the valve. 

A powerful three-band EQ – Bass, Middle and Treble, each with up to 12dB of cut and boost – offers plenty of sonic sculpting capability, particularly in the midrange, to place the drive in the mix or to tune it to perfectly complement your amp.  

Although there are some really driven tones available from the pedal, our preference is with the Drive at lower levels (and the rest set accordingly) in that role of transparently adding an extra switchable channel to our amp, all with a sensitive amp-like response to pick attack. 

Verdict: It ain’t cheap, but it’s real valve overdrive that can easily slot onto a pedalboard.

Specs

  • PRICE: £295
  • ORIGIN: Germany
  • TYPE: Drive pedal
  • FEATURES: True bypass, ECC83/12AX7 valve
  • CONTROLS: Drive, Volume, Bass, Middle, Treble, Bypass footswitch
  • CONNECTIONS: Standard input, standard output
  • POWER: 9V DC adaptor (not supplied) 500mA
  • DIMENSIONS: 120 (w) x 100 (d) x 48mm (h)

Vahlbruch SpaceTimeTap Delay

(Image credit: Future / Olly Curtis)

The SpaceTimeTap features digital repeats, while the dry signal remains resolutely analogue in a parallel path through the pedal so there’s no messing with your original tone. 

While the Time, Repeats and Mix knob are standard for any delay pedal, you do get some adjustment of the sound of the repeats via a three-way tone switch that reduces top-end. 

The SpaceTime's MagTraB switching works brilliantly in a tap tempo context, delivering what might just be the smoothest we’ve seen in a delay pedal

The Bright setting gives you the most clarity with repeats that naturally mimic your guitar tone, while the Mellow and Dark settings are progressively less bright and melt away really nicely into the ether.

With probably the three most-used time divisions, the tap tempo footswitch is a practical asset and its MagTraB switching works brilliantly in a tap tempo context, delivering what might just be the smoothest we’ve seen in a delay pedal. 

While you could get a decent multi-program delay pedal for the same price, this pedal’s virtue is that it just does the essential but does it so very well.

Verdict: Basic facilities for the price, but it scores on sound quality and simplicity of use.

Specs

  • PRICE: £235
  • ORIGIN: Germany
  • TYPE: Delay pedal
  • FEATURES: Selectable true or buffered bypass, selectable trails, 600ms max delay time, tap tempo, available with either creme or black knobs
  • CONTROLS: Time, Repeats, Mix-Level, Tap Division switch (eighth, quarter, dotted eighth), Tone switch (Mellow, Bright, Dark), Tap Tempo footswitch, Bypass footswitch, internal true/buffered bypass switch, internal ‘kill dry’ switch, internal ‘trails on’ switch
  • CONNECTIONS: Standard input, standard output
  • POWER: 9V DC adaptor (not supplied) 60mA
  • DIMENSIONS: 120 (w) x 100(d) x 48mm (h)

Vahlbruch Quantum Compressor

(Image credit: Future / Olly Curtis)

What do you like at the front-end of your signal chain? A compressor? A buffer? Well, the Quantum can fulfil both functions. 

It’s a compressor, but you can set it up for true or buffered bypass (it has an extra LED to let you know that it’s in buffered mode). 

There are standard knobs for compression and output volume – with loads of leeway to add boost – but the photocell-based compressor has two modes of operation: standard serial compression or parallel compression, basically mixing dry sound with the compressed signal. 

You’d have more control over this with a Dry knob dialling in the exact mix of dry and compressed, but the setting that’s been chosen here seems to strike the right balance between keeping your front-end dynamics and adding the benefits of compression. 

If you want Dyna Comp-style squashiness, it’s all there in Serial mode, but you may be tempted to keep that Parallel mode’s subtle tone conditioning on all the time.  

Verdict: A practical two-in-one pedal with plenty of options as to how you use it.

Specs

  • PRICE: £195
  • ORIGIN: Germany
  • TYPE: Compression pedal
  • FEATURES: Selectable true or buffered bypass. buffer on LED, dynamic processing LED
  • CONTROLS: Compression/Sustain, Volume, Serial/Parallel switch, Bypass footswitch, internal true/buffered bypass switch
  • CONNECTIONS: Standard input, standard output
  • POWER: 9V DC adaptor (not supplied) 40mA
  • DIMENSIONS: 70 (w) x 115 (d) x 48mm (h)
  • CONTACT: Vahlbruch FX