The Cornerstone Gladio SC is a single-channel overdrive preamp pedal, handmade in Italy by Cornerstone1. It is a compact version of the company's Gladio Double Preamp: Cornerstone says it is "based on the Gladio 1st channel, with the exact same sound and controls," with one new feature, the Clean knob1. Like the full Gladio, its design goal is Dumble preamp saturation, the sound of the rare amplifiers built by Alexander Dumble2.
The idea behind the pedal is specific. Cornerstone says the Gladio SC "tries to take a step closer to the Steve Ray Vaughan sound, which was achieved using a Dumble amplifier too"1. The Clean knob is the tool for that: it blends your untouched clean signal back over the drive, thickening the low end and changing how the compression feels on the attack.
A single-channel Dumble-style overdrive
The Gladio line is Cornerstone's take on the Dumble sound. Cornerstone describes the Gladio as "an Overdrive with a realistic tube-compression behavior," and states plainly that "the design goal had a name: Dumble"2. Delicious Audio has covered the family the same way, calling the Gladio "an amp-in-a-box inspired by the rare line of Dumble amps"5.
The original two-channel Gladio offered S (single) and D (double) modes: in single mode, engaging one channel turns the other off, and in double mode the two channels stack "to reach a huge fat Dumbl-esque sound"6. The Gladio SC takes the simpler route: one channel, one footswitch, and a much smaller footprint. Guitar.com's reviewer noted that "with top-mounted jacks and a roughly compact-pedal size case, the Gladio SC is far more pedalboard friendly than its larger sibling"3. The original Gladio was retired in 2022, and the line has since continued with the Gladio MkIII6.
The Clean blend and the other controls
The Clean knob is the pedal's defining control. The clean signal is taken directly at the pedal's input and mixed back with the overdriven signal at the output, and the CLEAN knob sets the volume of that clean layer1. Cornerstone describes three effects as you turn it up:
| What the Clean knob changes | What Cornerstone says happens |
|---|---|
| Bottom end | "the sound becomes fatter"1 |
| Compression | the non-compressed clean sound comes into the mix, with the change in compression "particularly accentuated" on the attack1 |
| Saturation | the final output becomes hotter and better able to push the front end of your amp1 |
One practical detail: Cornerstone says the knob's effect is noticeable within roughly the first 40% of its rotation, so most of the action happens early in the sweep1. Guitar.com's reviewer summed up the control this way: "The Clean control mixes in your clean signal (which is taken at the pedal's input and mixed back in with the overdriven signal at the output)"3.
The pedal also carries a two-way compression switch. On his demo, reviewer Pete Thorn compared the settings: with less compression engaged, he said, "it got a real just kind of nasty open distorted amp sound"7.
Power and connections
The Gladio SC runs on 9V DC only, through a 2.1mm center negative adapter, and draws 60mA423.
There is no battery option, so the pedal needs a spot on a power supply. At 60mA it is an easy load for any isolated supply, and the center negative polarity matches the standard used by most pedalboard bricks43.
Input and output are on top-mounted jacks, which saves width on a board, and the case measures 122 x 67 x 39.5 mm3. Guitar.com's reviewer also liked the look, noting "it looks lovingly made, with its elegant aluminium finish nodding subtly to the late Alexander Dumble's much hyped creations"3.
The SRV question
Cornerstone is direct about the target: the Gladio SC aims toward the Stevie Ray Vaughan sound, which Vaughan achieved with a Dumble amplifier1. RockBoard's PedalPedia entry puts it as "Start your Texas blues journey here," with the Clean volume knob as the way in4. Pete Thorn, demoing the pedal with humbuckers and with single coils on his old strats, framed the design the same way: "what they were trying to do is give you a little bit more of that steel string singer stevie ray vaughan thing"7.
It is worth keeping the history straight. Vaughan's best documented overdrive was the Ibanez Tube Screamer; Analog Man's history of the pedal notes that "SRV used the TS-808 for his trademark juicy strat tone"8. The Gladio SC is chasing the Dumble side of his rig, not the screamer side.
What reviewers said
Pete Thorn's verdict was strong: "i think this is the best sounding dumbbell style pedal that i've tried," adding that it feels the most amp-like overall7.
"All the high-class tones of the original in a more compact format, and that Clean control makes this a hugely versatile"
In his demo, Thorn played the pedal through a looper with both humbuckers and single coils, and explored the compression switch for more open, distorted amp sounds7.
Videos
Pete Thorn
Cornerstone Music Gear
Cornerstone Music Gear
Questions
Does the Cornerstone Gladio SC take a battery?
No. The Gladio SC runs on a 9V DC power supply only, through a 2.1mm center negative adapter, and has no battery option. Plan on a spot on a pedalboard power supply.
Is the Gladio SC true bypass?
Yes. Guitar.com's review notes the pedal has a true bypass footswitch, so it stays out of your signal path when it is off.
What is the difference between the Gladio and the Gladio SC?
The Gladio SC is based on the first channel of the two-channel Gladio, with the same sound and controls, but in a smaller box and with one addition: the Clean knob, which blends your uncompressed clean signal back over the drive. The original Gladio was retired in 2022.
Can the Gladio SC get Stevie Ray Vaughan's tone?
Cornerstone says the Gladio SC aims a step closer to the Stevie Ray Vaughan sound, which Vaughan achieved with a Dumble amplifier, by adding the Clean volume knob. Reviewer Pete Thorn described it as more of that steel string singer, SRV thing. It is an approximation of that amp style, not a copy of any one rig.
Where is the Cornerstone Gladio SC made?
Cornerstone builds its pedals by hand in Italy, and the Gladio SC is part of that handmade lineup.
Sources (8)
- Gladio SC, Cornerstone
- Gladio V2.1, Cornerstone (cornerstonegear.it)
- Cornerstone Gladio SC review: The most pedalboard-friendly Dumble pedal around?, Guitar.com, 2022-03-01
- Gladio SC by Cornerstone Music Gear, RockBoard PedalPedia, 2026
- Cornerstone Nero Fuzz, Delicious Audio, 2024-09-16
- Updated Pedal: Cornerstone Gladio MK 3 D-Style Double Preamp, Delicious Audio, 2026-10-21
- THE BEST "DUMBLE IN A BOX!" CORNERSTONE GLADIO SC PREAMP, YouTube (Pete Thorn channel), 2021-03-20
- Ibanez Tube Screamer History, analogman.com, 2023
Stevie Ray Vaughan
