The Cornerstone Gladio Double Preamp is a dual overdrive pedal, made in Italy, built to put two Dumble-style drive voices in one enclosure1. It was created to faithfully recreate the hugely sought after, and hugely expensive, tones of Alexander Dumble's amplifiers, according to Guitar.com's 2021 round-up of premium pedals2. Each channel has its own gain, volume and tone controls, and a mode switch lets you run them alone or stacked together1.
What it does for your sound
The two channels are not identical drives. Guitar.com's reviewer, Ed Oleszko, described channel one as offering smooth soft clipping, huge sustain and dazzling, amp-like touch response at lower gain, with focused, articulate lead tones as the gain comes up. Channel two brings more aggressive hard clipping; his P-90-equipped Goldtop, he wrote, enjoyed side two's harder edge1.
The channels were designed with reference points in mind. Oleszko quoted the designer as saying the pedal was inspired by two specific songs: Cannonball Shuffle by Robben Ford for channel one, and Elemental Journey by Sonny Landreth for channel two1.
Guitar.com's verdict on the pedal as a whole was generous. In the 2021 premium pedals feature, the publication pointed to:
"the Gladio's huge, eloquent tones, precise note attack, effortless sustain and uncanny ability to make every amp and guitar you use with it sound bigger, clearer and better"2
Guitar.com, 20212
The controls
| Control | What it does |
|---|---|
| Gain, volume, tone (per channel) | Independent gain, volume and tone controls for each channel1 |
| Single/double mode switch | Runs one drive at a time, or stacks both drives together in double mode1 |
| Comp switch | Lower headroom and a smoother ride, per Guitar.com's review1 |
| Jazz/Rock switch | Changes the midrange voice; the rock position particularly suits American-voiced slide that verges on fuzz1 |
On the Jazz/Rock switch, That Pedal Show's Mick Taylor offered a practical read of it in the demo: "it rolls a load of high-end off... and in so doing I'm guessing it must be pregain"3.
Stacking the two channels
The single/double mode switch is the heart of the pedal's flexibility. In single mode you get one drive voice at a time; in double mode both are active and can be stacked. Guitar.com's reviewer found that stacking both drives could "transform a vintage combo into a colossal multi-channel monster"1.
Power and practicalities
The Gladio runs on a 9V power supply only, using a DC 2.1mm center negative adaptor, and has no battery option1. Switching is true-bypass1. The enclosure measures 118 x 94 x 43 mm1.
Because the pedal takes a 9V power supply only, it cannot run on a battery. Give it its own output on a pedalboard power supply.
Versions, and where the Gladio sits in the range
The site also covers the Cornerstone Gladio V2.1 and the single-channel Cornerstone Gladio SC, which sit alongside the original double preamp in the range.
Cornerstone has since built a wider family of dual drives around the Gladio's Dumble-style circuit, including the Cornerstone Colosseum, the Cornerstone Imperium V2, which pairs Gladio-style and Antique-style drive circuits, and the Cornerstone Imperivm Daje Drive, which combines the Antique Screamer and Gladio Dumble circuits. For the wider context, see the site's pages on Overdrive Pedals and Preamp Pedals.
What reviewers said
Guitar.com's reviewer was struck, on first plugging in, "both by the audacious weight of the tone, and the sheer gain and headroom available on tap"1.
Pete Thorn, reviewing on his YouTube channel, placed the pedal in its stylistic camp: "the gladio and the gladio double preamp and those were much more sort of in the dumbbell camp"4.
That Pedal Show has also used the pedal on the show, listing the Cornerstone Gladio Double Preamp among the gear used in a 2021 episode5.
Review videos
The pedal's two channels and its jazz/rock switch are central to how it works: each channel has independent gain, volume and tone controls, and the maker designed channel one around Robben Ford's "Cannonball Shuffle" and channel two around Sonny Landreth's "Elemental Journey"1. Pete Thorn has said of the Gladio and the Gladio double preamp that "those were much more sort of in the dumbbell camp"4.
Pete Thorn's 2021 review video covers the Gladio and the Gladio Double Preamp, placing both in the Dumble-style camp of overdrives4.
Videos
Pete Thorn
Shawn Tubbs
R.J. Ronquillo
Sources (5)
- Review: Cornerstone Gladio Double Preamp, guitar.com, 2021-01-14
- Gear Of The Year: Best Premium Effects Pedal of 2021, Guitar.com, 2021-12-09
- Cornerstone Gladio, Neunaber Inspire, Walrus Slö, Aclam Dr Robert TPS Pedal Jams, That Pedal Show (YouTube), 2020-02-26
- JOHN MAYER TONES, YouTube (Pete Thorn channel), 2021-06-23
- Uni-Vibe Vs Harmonic Tremolo Plus Fuzz & OD Order, That Pedal Show, 2021-04-30
