Ibanez Thermion

Ibanez entered the pro-amp arena in big way this year with the introduction of the Thermion, the company’s first all-tube amplifier. The moniker is a take on the original term for the world’s first vacuum tube, “thermionic valve,”and the Chinese-made Thermion celebrates the technological achievement by having an all-tube signal path—even the effects loop is completely tube coupled. The rectifier incorporates fast-switching, soft-recovery diodes to elicit some of the dynamic feel of a tube rectifier, and, for low noise, the filaments of the preamp tubes are lit by a DC supply. A helpful bias-adjust feature (which includes an external momentary switch and meter test points) makes it easy to configure the amp for more muscular 6550 power tubes. The Thermion also sports a Dampening switch on the Hot channel that allows you to deactivate the speaker dampening for a thicker, more aggressive distortion sound. Controlling this function via footswitch requires connecting a secondary mono (tw
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Thermion, Dead Man

You get quite a light show from this amp when the mains are switched on. The logo is backlit in orange and lights up when the standby switch is thrown, Green LED indicators light up above the Gain and Master controls on the Vintage channel (ditto for the Hot channel, which has red LEDs), and there are even LEDs above the Send and Return controls that illuminate when the effects loop is switched on. These LEDs make it easier to grab the most critical knobs under low-light conditions, but being able to see the actual settings is tricky due to the fact that these Tele-style knobs have very minimal markings and the reflections off their chromed bodies can really mess with your ability to see where they’re pointed.


After plugging into the single input jack, you can opt to send either a full (Hi) or a 6dB-attenuated (Lo) signal into the first gain stage by using the adjacent Sensitivity switch. I kept the switch in the Hi mode most of the time, but found the Lo setting useful for obtaining very clean tones from humbucker guitars on the Vintage channel, or for extracting a little more clean headroom from the Hot channel when using higher-output guitars.

The Vintage channel remains very clean until the Gain knob is turned past the halfway point. From there, the distortion comes on smoothly until reaching a level of saturation at the highest setting that’s suitable for bluesier lead playing and grindy rhythm work. The Thermion sounds aggressive and punchy at higher Gain settings and gets loud fast as you crank up the Master. Guitar volume dynamics are tracked well by this channel, and the tone controls are nicely voiced. Mid settings for all proved to be a good starting point for a PRS McCarty, a Fender Eric Johnson Signature Stratocaster, and an ’80s-era Fender Tele, with only some mild tweaks of the Presence and Treble controls needed to get the highs in shape.

Good as this channel is, however, it pales in comparison to the Hot channel, which delivers stout grind at lower Gain settings and goes straight to the tear-your-head-off zone when turned up. And that’s with the Dampening switch on, which keeps the response fairly tight over a wide range of overdrive settings. Flick the Dampening switch to the opposite setting, however, and the Thermion reacts like you’ve hit the saturation afterburner, churning out distortion so thick and heavy that we found it necessary to nudge up the Treble and Presence to get the right clarity on a Tele’s bridge pickup! You can soar into the stratosphere of high-gain soloing in this mode, and the looser, spongier feel in this mode is quite cool for lead playing. The footswitchable Dampening function really extends the Thermion’s overdrive capabilities, and is more effective than the typical boost option offered on many amps because it gives you two very distinct tonal and dynamic palettes to work with. If you still need more thrust to catapult your solos (or give your audience a preview of Armageddon with some raging feedback), there’s one more trick you can pull off: Select the Blend (parallel) setting on the effects-loop switch, turn up the Send and Return controls to further increase the amp’s gain (assuming there are no external devices connected in the effects loop), then toggle the loop on and off as needed for an extra gain/volume boost. The send/return circuitry isn’t voiced for optimum tone, but it can certainly deliver a big kick in level (Ibanez says that even more gain can be obtained with the loop set to Series mode—albeit with increased noise.).


The Thermion is a very flexible and capable stage amp that covers the bases from super clean to wickedly distorted. I love the inherent simplicity of this amp, and kudos to Ibanez’ engineers for figuring out how to use something as tweaky as speaker dampening to so effectively expand the Thermion’s overdrive capabilities. Considering what the Thermion offers for such a reasonable price, it’s definitely worth some tryout time if you’re on the prowl for a hot rock rig.