Thermion Zero Dynamic Hybrid Amplifier review

Spanish pedal wizard Thermion has cooked up a compact stereo power amp that lets you enjoy your pedals anywhere

Thermion Zero Dynamic Hybrid Amplifier
(Image: © Future / Olly Curtis)

Guitar World Verdict

If your crucial tones are provided by pedals and you’re looking for a more portable solution than a traditional backline, this could be just the ticket.


  • +

    High-quality valve-like sounds from a compact but robust package.

  • +


  • +

    Good analogue speaker emulation.

  • +

    Great value for money.


  • -

    All-white footswitch LEDs could make it difficult to check status on a dark stage.

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Compact, portable and good-looking, Thermion’s Zero Dynamic Hybrid guitar amp is the company’s solution to the ‘how do I amplify my pedals without a big heavy combo amp?’ predicament. 

The robust 2mm steel case is filled with all the goodies any pedal player could ask for, including a stereo 40 watts per channel Class D output stage, a pair of stereo balanced speaker-emulated outputs and a headphones socket, with a separate level control. 

There’s a built-in analogue ‘overdrive pedal friendly’ clean preamp, too, with Bass, Middle and Treble knobs, plus a three-way Bright switch and a digital reverb with short, medium and long modes.

Thermion Zero Dynamic Hybrid Amplifier

(Image credit: Future / Olly Curtis)

The Zero benefits from two loops: a mono ‘preamp loop’ that allows players to replace the Zero’s built-in preamp, and a mono-send/stereo-return effects loop. Both loops are footswitchable, along with the reverb.

The build quality is excellent, with exceptionally neat hand soldering, and the unit itself is small enough to fit comfortably on most average pedalboards, with an integrated go-anywhere mains power supply, so no wall-warts to trip over. In use, it’s impressively transparent, with hiss and hum levels low enough not to intrude, while the clean preamp EQ is smooth and predictable, making it easy to dial in any guitar. 

We tried out the Zero using a Zoom MultiStomp as an alternative preamp, plus a Korg G4 rotary speaker simulator in the effects loop. Plugged into a stereo 2x12 cabinet loaded with Celestion V30s, the Zero has plenty of power available, sounding refreshingly ‘real’ with valve-like dynamics and punch.

Thermion Zero Dynamic Hybrid Amplifier

(Image credit: Future / Olly Curtis)

Stereo is great. Many modulation effects can run in stereo and while our venerable G4 sounds good in mono, the three-dimensional spatial swirling makes a huge difference, especially with the analogue speaker-emulated outputs hooked up to a PA. There’s a small temperature-controlled fan, which is mostly off but can cut in to aid ventilation under more extreme conditions.

Teamed with a pair of lightweight 1x12s, Thermion’s Zero will turn your pedalboard into a highly portable stereo rig with all the bells and whistles you need for live performance, as well as recording and home practice.


Thermion Zero Dynamic Hybrid Amplifier

(Image credit: Future / Olly Curtis)
  • OUTPUT POWER: 2x40W @ 8ohm
  • CONTROLS: Preamp: Bright (1, 2, off), Treble, Mid, Bass, Reverb mix, Reverb type: (Short, Medium, Large), Balanced output & headphones volume, Power amp standby, Power amp volume, Footswitch Reverb On/Off, Footswitch Effects loop On/Off, Footswitch, Internal preamp On/Off
  • CONNECTIONS: Guitar input, Effects loop send, Effects loop return L (mono), Effects loop return R (stereo), Preamp loop send, Preamp loop return, ‘Analog Speaker Modelling’ balanced XLR output, L ‘Analog Speaker Modelling’ balanced XLR output, R ‘Analog Speaker Modelling’ headphone output, Power Output L @8ohm, Power Output R @8ohm
  • DIMENSIONS (WxHxD): 25x8x16cm
  • WEIGHT: 2.2kg
  • CONTACT: Thermion

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Nick Guppy

Nick Guppy has been a regular contributor to Guitarist magazine for over 20 years, mostly writing reviews on guitar amps and related products. He built his first valve amplifier at the age of 12 and has since bought, sold and restored many more, with a particular interest in Vox, Selmer, Orange and tweed-era Fenders, alongside Riveras and Mark Series Boogies. When wielding a guitar instead of soldering iron, he’s enjoyed a diverse musical career playing all over the UK, including occasional stints with theatre groups, orchestras and big bands as well as power trios and tributes. His favourite musical genres are ‘anything that’s good’.