Strymon Iridium

The Strymon Iridium is an amp modeler and speaker cabinet simulator in a pedal, built to sit at the end of a pedalboard and replace an amp for headphones, recording or going straight to a PA. It models three classic tube amplifier circuits and pairs them with nine stereo impulse response speaker cabinets, plus a room ambience control for a sense of space. Strymon describes it as an amp modeler solution in a pedal format that you can drop into any pedalboard¹.

It launched in 2019 at $399². A retailer lists it at $399.99 USD as of October 2026³. The signal path is digital amp and cab processing behind an analog front end: a stereo high impedance discrete JFET preamp with up to 22dB of pure analog gain, with a SHARC DSP doing the modeling⁴.

What the Iridium does: three amps, cab IRs and room

The Iridium gives you three amp models, each paired with a choice of three cab IRs, plus a ROOM knob that controls natural room ambience with a secondary function to toggle between small, medium and large room sizes⁴. The cab IRs run at full stereo 24bit 96kHz resolution for their entire 500 milliseconds⁵. Strymon curated the nine factory IRs from vendors Cabir.eu, Celestion, Ownhammer and Valhallir.at⁵.

The ROOM knob's three sizes let you dial in anything from a tight recording booth feel to a larger space, and the ambience sits after the IR cabinet in the internal routing⁴⁶.

The amp models: Round, Chime and Punch

Each amp model is based on a specific classic circuit, and each has its own character as Strymon describes it⁴:

The MIDDLE knob behaves differently per amp: on Round and Punch it adjusts the tone stack to highlight middle frequencies, while on Chime it rolls off high frequencies as you turn it up, acting like the AC30's Tone Cut control⁴⁷. On Chime, a frequency-shaped front end boost is added at the top end of the Drive range⁷.

The nine factory cabs cover Fender, Vox, Marshall and Mesa/Boogie configurations⁸:

• 1x12 Fender Deluxe Reverb (OwnHammer impulse of a vintage Deluxe Reverb 1x12 open back combo with a 1978 Fender CTS ceramic 12 inch speaker)⁴⁸
• 1x12 Fender Blues Junior (cabIR impulse, Jensen C12N speaker)⁴⁸
• 2x10 Fender Vibrolux (cabIR impulse, 1965 Vibrolux with Jensen C10NS speakers)⁴⁸
• 2x12 Vox AC30-6 open back fawn⁸
• 1x12 Custom cab with Celestion Blue Alnico⁸
• 4x12 Mesa/Boogie Half-Back⁸
• 4x12 Marshall with Celestion G12M-25s⁸
• 2x12 Custom cab with Celestion Vintage 30s⁸
• 8x12 Marshall with Celestion T652s⁸

The CAB knob selects one of three complementary cabs for each amp type, and each cab contains two IRs, left and right, which can be replaced using Strymon's Impulse Manager software⁴.

Controls and connections

The front panel keeps things simple: DRIVE, BASS, MIDDLE and LEVEL knobs, a CAB knob, a ROOM knob, and two footswitches, ON and FAV. The FAV footswitch recalls a stored Favorite setting including all knob and switch settings; press and hold until the FAV LED blinks to save a new Favorite⁴.

The input is a single jack that works with mono or stereo TRS input signals depending on the Input Selector switch on the back, set to MONO, STEREO or SUM. Input impedance is 1 Meg Ohm, and the pedal accepts instrument level (-10dB) or line level (+4dB) signals up to +8dBu⁹. The input level mode is changed by pressing and holding the FAV footswitch while connecting power until both LEDs blink, then using the DRIVE knob to select, with GREEN for instrument level and RED for line level⁹.

Output is stereo via LEFT and RIGHT jacks (use OUT L for mono), with a stereo 1/8 inch headphone output whose volume is set by the LEVEL knob⁴. Output level runs from instrument up to line level, adjustable by the LEVEL knob and a Level Trim secondary function that boosts or attenuates output without affecting the leveling between stored presets¹⁰.

Power and connections: 9V, 500mA

The Iridium runs on 9V DC center negative, and Strymon's product page specifies a minimum of 500mA, with the power supply not included⁴. The current requirement depends on how you use it:

• Headphone output not in use: Strymon recommends at least 300mA¹
• Headphone output in use: Strymon recommends at least 500mA¹

For headphones, Strymon recommends an impedance between 25 to 70 ohms and sensitivity as close to 100dB/mW as you can get¹. Like most guitar pedals, the Iridium receives its ground connection via the 1/4 inch output jacks, so when listening through headphones with a wall adapter and nothing plugged into the outputs, some hum can appear. Strymon says the hum can be eliminated by connecting LEFT or RIGHT OUT to the input of an amplifier with an earth ground connection, which does not need to be powered on, or by grounding the guitar via the strings¹.

Strymon also notes that in some setups, using a DI may help if you encounter noise or ground loops when connecting the Iridium's outputs directly to a PA or mixer¹¹. The buffered signal, engaged or bypassed, can handle sending signals over long cable runs¹¹.

Presets, MIDI and expression

The Iridium stores one Favorite preset on the pedal itself, accessible from the FAV footswitch⁴. Add a MultiSwitch Plus and you get four footswitchable presets at your feet⁴. Connect a MIDI device through the EXP jack and you get full MIDI control with remote parameter control and access to 300 preset locations, which requires a Strymon MIDI EXP cable or a MIDI to TRS interface⁴.

The EXP/MIDI jack is a multi-function communication jack. A standard TRS expression pedal can act as a volume pedal before the amp, and the jack also accepts a Strymon MiniSwitch, MultiSwitch Plus or MIDI EXP cable⁴. The volume pedal mode can be set to Volume PRE, placed right before the amp modeling, or Volume POST, placed right after the IR cabinet but before the room ambience⁶.

Firmware updates and factory reset

Firmware is loaded through the USB jack on the back, which is also used to load IR files from a computer⁴. The current firmware release is Rev 1.33, released November 2024, which adds compatibility with Nixie 2.0 and must be updated via Nixie 2.2.0¹². Strymon has also released firmware updates for Iridium addressing minor issues and adding requested new features¹³. A factory reset clears out and restores all factory presets, expression pedal assignments, secondary functions, customized IR cabs, and power up modes: press and hold the ON footswitch while connecting power to the pedal, release the footswitch once both LEDs flash, then follow the knob turns, Turn 1 AMBER, Turn 2 RED, Turn 3 AMBER¹⁴.

To load third-party IRs, connect the powered pedal to your computer with the included USB-mini cable and use the Strymon Impulse Manager software¹⁵. IRs must be mono or stereo 24 bit 96 kHz .wav files up to 500ms in length; files that do not meet this criteria are rejected by the software¹⁶.

A factory reset clears factory presets, expression pedal assignments, secondary functions, customized IR cabs and power up modes¹⁴. The procedure:

1. Press and hold the ON footswitch while connecting power to the pedal¹⁴
2. Sweep the MIDDLE knob from 0% to 100% twice; status shows on both LEDs¹⁴
3. Watch the knob turns: Turn 1 AMBER, Turn 2 RED, Turn 3 AMBER, Turn 4 both LEDs blink RED as the pedal resets and power cycles¹⁴
4. Once both LEDs flash, release the footswitch; when the ON LED lights up RED after the power cycle, the pedal is ready to use again¹⁴

Where it came from and what reviewers said

Strymon announced the Iridium on October 23, 2019, priced at $399². Its development began while Strymon was working on the tube and cascading gain emulation created for the Riverside, and the Iridium shares the Riverside's knob organization, with the exception of a Room control on the bottom right⁷. Inside, a 32-bit floating-point SHARC ADSP-21375 processor works with an ARM co-processor to deliver the 24-bit 96kHz 500ms impulse responses¹⁷.

The Iridium carries a list price of $399.99 USD, in a pedal format measuring 12 × 6 × 4 in³. Strymon designed it as an amp modeler solution in a pedal format that you can drop into any pedalboard¹, with a strong and lightweight anodized black aluminum chassis, designed and built in the USA¹.

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