The Boss ST-2 Power Stack is a compact distortion pedal from Boss, announced in 2010, that aims to give a guitarist "both the sound and feel of playing through a large, cranked-up, stack-style tube amplifier"1. Rather than modeling one specific amp, it uses Boss's amp modeling research to cover a range of stack tones, from fat crunch through punchy drive to ultra-high gain distortion, all from a single knob1.
MusicRadar later described its place in the lineup plainly: the ST-2 "brought the sound of a raging stack amp to pedalboards everywhere"2. It was followed in 2011 by the Boss BC-2 Combo Drive, which took the same amp-in-a-pedal idea in a combo-amp direction2.
What it does: a cranked stack amp in a pedal
Boss positioned the ST-2 as "a unique type of BOSS distortion pedal," one built around the experience of a big tube stack pushed hard1. The company said this is accomplished through its years of research in amp modeling1. In Pete Thorn's demo video, Boss claimed the pedal "would turn my clean amplifier into a raging wall of British Distortion Mayhem"4.
The single SOUND knob is the heart of it. Boss says that with this one control, players can dial in three distinct stack tones, from fat crunch to punchy drive to ultra-high gain distortion, and every color in between1. Thorn described how it behaves as you turn it:
"it will add Distortion and gain as you turn it up but it also sort of morphs the pedal between different amp-like sounds"4
Pete Thorn, demo video4
Controls
| Control | What it does |
|---|---|
| SOUND | Dials in three distinct stack tones, from fat crunch to punchy drive to ultra-high gain distortion, and everything in between1 |
| Level | A level control, which is like a volume4 |
The pedal uses Boss's silent footswitch, which Premier Guitar's reviewer called excellent3.
How the SOUND knob maps to amp sounds
Thorn's demo gives the clearest picture of what the SOUND knob does across its range14:
"when it's turned all the way down it sounds sort of like a Plexi as you get more towards the middle it's like a jcm or like an 80s style sound and you turn it up higher and it uh sounds much more like modded crazy gain"4
Pete Thorn, demo video4
So the low end of the knob leans toward vintage British stack character, the middle toward 80s high-gain territory, and the top end toward modded, very high gain distortion4.
Into a clean amp
The ST-2 is designed around the clean-amp use case. Premier Guitar's reviewer tested it exactly that way, playing a Les Paul Custom into a 3rd Power American Dream amp switched to its clean blackface channel3. Boss's own framing, as Thorn reported it, was that the pedal turns a clean amplifier into that cranked stack sound4.
What reviewers said
Premier Guitar's review was largely positive, with one noted limitation:
"Perhaps the ST-2's only shortcoming is a lack of midrange control."
Premier Guitar3
The reviewer found the pedal has an inherent midrange heaviness that can sound like a half-cocked wah depending on the amp and guitar settings, and with no mid knob there is no way to shape it from the pedal itself3. Players who like to dial their midrange may want to shape it elsewhere in the chain.
History: Boss amp modeling in a compact pedal
Boss announced the ST-2 Power Stack in September 2010 as an addition to its compact pedal lineup, with an MSRP of $162.001. It stood out from the company's long-running overdrives like the Boss SD-1 Super Overdrive and Boss BD-2 Blues Driver by taking an amp-modeling approach to gain rather than a traditional clipping circuit1. The following year Boss extended the idea with the BC-2 Combo Drive, launched as a companion piece to the ST-22.
Review and demo video
Pete Thorn's demo video walks through the SOUND knob from low to high, showing the Plexi-like low settings, the JCM-style middle, and the modded high-gain top end, and demonstrates the pedal into a clean amp as Boss intended4.
Videos
ProGuitarShopDemos
ProGuitarShopDemos
Questions
Is the Boss ST-2 an overdrive or a distortion?
Boss introduced it as a distortion pedal, but it is built to cover the whole gain range of a cranked stack amp. The SOUND knob moves through three zones: fat crunch, punchy drive, and ultra-high gain distortion, so it can sit anywhere from overdrive to full distortion depending on where it is set.
Does the Boss ST-2 have a mid control?
No. The controls are the SOUND knob and a level control, with no dedicated midrange knob. Premier Guitar's reviewer called the lack of midrange control perhaps the pedal's only shortcoming, noting its inherent midrange heaviness can sound like a half-cocked wah depending on the amp and guitar.
Does the Boss ST-2 Power Stack sound like a Marshall?
In Pete Thorn's demo video, low SOUND settings sounded sort of like a Plexi, the middle of the range like a JCM or 80s style sound, and higher settings much more like modded, crazy gain. Boss's own claim, as Thorn reported it, was a raging wall of British distortion mayhem.
Does the Boss ST-2 work into a clean amp?
Yes. Premier Guitar's reviewer tested it playing a 1974 Les Paul Custom into the clean blackface channel of a 3rd Power American Dream amp, which is exactly the use case Boss designed it for: turning a clean amplifier into a cranked stack sound.
How much does a Boss ST-2 cost?
At launch in September 2010 the ST-2 carried an MSRP of $162.00, with a street price of $99 reported by Premier Guitar. It was announced as part of Boss's compact pedal lineup and became available in September 2010.
Sources (4)
- Boss Introduces ST-2 Power Stack Pedal, Premier Guitar, 2010-09-01
- Boss launches BC-2 Combo Drive pedal, MusicRadar, 2011-09-15
- Boss ST-2 Power Stack Pedal Review, Premier Guitar, 2010-10-20
- Boss ST-2 Power Stack demo, by Pete Thorn, youtube.com, 2010-11-02
