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Reactor IV


BACKORDER: Orders will be shipped the following quarter.

E.g. orders placed in Q1 (Jan,Feb,Mar) will be shipped in Q2 (Apr,May,Jun).

SKU: A420 Category:

Ultimate Versatility

Channel I (Clean Channel)

Channel I represents the clean channel of the Reactor IV and offers sparkling, clean tones. Bass, middle and treble  knobs give you total control of its EQ-section. A shift switch changes the range of frequencies controlled by the EQ-section. Channel I has a volume knob to match its output level with channel II.

Channel II (Lead Channel)

Channel II represents the lead channel of the Reactor IV. It’s split in two different lead channels with their own gain setting. Gain I is a darker voiced lead channel compared to gain II and is ideal for mid-gain to high gain tones. It also offers a crunch switch to dial in some nice rock’n roll tones. Gain II offers a modern metal sound. Each gain channel has its own djent/doom 3-way switch. In djent mode the lower frequencies are tamed. In doom mode the highs are tamed and bass is boosted. The overall gain of the channel is also increased which results in a nice fuzzy doom sound. The centre position of the djent/doom switch provides a neutral sounding preamp which is preferred for mid-gain sounds. A shared tone stack with bass, middle and treble knobs gives you total control of the EQ-section. A 3-way shift switch changes the range of frequencies controlled by the EQ-section. Channel II also offers a Low Pass Filter (LPF) which can be useful when recording. As you can imagine the versatility of this preamp will blow your mind.

Total control

The REACTOR IV offers total control over your effects by implementing two FX loops. Each FX loop can be set as a parallel or series loop. In parallel mode the dry signal of the preamp can be mixed with the signal coming from your effects. In series mode the output volume of your effects chain can be matched with the bypassed volume of the amp. Loop I and loop II can be assigned to each channel of the amp or they can be controlled by an external foot switch. Channel I/II and master I/II (gain I/II) are switchable as well by an external foot switch.

The power amp you’ll love

The power amp of the REACTOR IV is one of a kind. It offers two master volume controls (one for each gain setting of channel II), a presence knob and a depth knob. A Negative FeedBack (NFB) switch allows you to achieve a more vintage or modern sound. The NFB can be disabled by turning the depth knob counter-clockwise. This will increase the gain of the amp. On the back of the REACTOR IV you will find external bias adjustment which makes it easy to change tubes. A pentode/ultra-linear switch is also embedded in the design. Pentode mode is the usual configuration you will find in most tube amps. In ultra-linear mode the bandwidth of the power amp will be extended but you’ll lose some output power. We recommend using the ultra-linear mode when the NFB of the amp is disabled.

Customize to your needs

As with all of our amps the REACTOR IV is fully customisable to your needs. You can choose your favourite tolex color/texture, ask for different hardware (corners, knobs, handle,…), select your favourite front panel or choose different power tubes. Check out our customizing tab for more info. Something different in mind? Contact us and we’ll see if we can meet your needs!


  • Preamp valves: 6 x 12AX7/ECC83 tubes**
  • Controls channel I: Bass, Middle, Treble and Volume knobs; Shift switch
  • Controls channel II: Gain I, Gain II, Bass, Middle and Treble knobs; Doom/Djent (for each gain), Crunch (only Gain I), LPF and Shift switches
  • Controls master section: Master I, Master II, Presence and Depth knobs; NFB switch and NFB disable (by turning depth knob counter-clockwise)
  • Lit logo: Selectable color for each channel (dip-switches on back)
  • Front panel options: wood, tolex or metal with internal lighting
  • Dimensions: 68 x 28 x 31 cm (with feet and handle)
  • Shipping dimensions: 78.5 x 38.5 x 37 cm
  • Weight: 24.5kg

  • Output power: 120W*
  • Power valves: 4 x 6L6GC tubes (customisable)
  • Power amp outputs: 2 x 4Ω / 2 x 8Ω / 1x 16Ω
  • Power amp topology: Pentode/Ultra-Linear (switchable)
  • Bias adjustment: External test points and potentiometers
  • Input voltage selector: 110VAC / 120VAC / 220VAC / 240VAC
  • FX loop: two tube buffered FX loops
  • FX loop topology: Series or parallel (switchable)
  • FX loop controls: Mix (parallel), return level (series)
  • Footswitch: two 1/4″ TRS jacks (footswitch not included)
  • Footswitch I: Channel I/II, Master I/II (Gain I/II)
  • Footswitch II: FX loop on/off, FX I/II

*in pentode topology with four 6L6GC power tubes

**brands may differ