Brad Delson

In the PremierGuitar "In the Studio with..." source, it's pointed out that Delson uses the Engl Fireball 100.

As listed as part of his studio gear on PremierGuitars "In the Studio with Linkin Park", the Bogner Twin Jet is used by Brad Delson.

Brad Delson using mesa boogie dual rectifier amp head

Brad Delson used it while recording 'Meteora'.

In the PremierGuitar "In the Studio with..." source, it's pointed out that Delson uses the Orange TH100.

Brad Delson used it while recording 'Meteora'.

A Hiwatt Lead 100, run through a Marshall 1960A cabinet, was miked with both a Sennheiser MD 421 and a Shure SM57, and was featured primarily on more dynamic songs such as “Waiting for the End.”

In the PremierGuitar "In the Studio with..." source, it's pointed out that Delson uses the Chandler GAV19T.

Brad Delson uses the Mesa/Boogie Rectifier 4x12 cabinet in his signal chain, as shown in a photo on Guitar Chalk, detailing his amp settings for the "Hybrid Theory" and "Meteora" albums.

Delson opened the door to a sound room to show his amps. “Be sure not to knock any of the mikes,” cautioned Delson. In this wood-paneled room four separate stations housed brawny modern amps: an Orange TH100 head through an Orange 2x12 cabinet with Celestion Vintage 30 speakers, miked with a Heil PR 30, a Sennheiser MD 421, and a Royer R-121; a Chandler GAV19T head through an Orange 1x12 cabinet with a Vintage 30, miked with a Mojave MA-100 and a Neumann FET47; an Engl Fireball 100 through a Marshall 1960 cabinet , miked with a Shure SM57, an MD 421, and an FET47; and a Bogner Customized Twin Jet through a Bogner Ubercab, miked with a PR 30, an MD 421, and an R-121.

Delson opened the door to a sound room to show his amps. “Be sure not to knock any of the mikes,” cautioned Delson. In this wood-paneled room four separate stations housed brawny modern amps: an Orange TH100 head through an Orange 2x12 cabinet with Celestion Vintage 30 speakers, miked with a Heil PR 30, a Sennheiser MD 421, and a Royer R-121; a Chandler GAV19T head through an Orange 1x12 cabinet with a Vintage 30, miked with a Mojave MA-100 and a Neumann FET47; an Engl Fireball 100 through a Marshall 1960 cabinet, miked with a Shure SM57, an MD 421, and an FET47; and a Bogner Customized Twin Jet through a Bogner Ubercab, miked with a PR 30, an MD 421, and an R-121.

In this video you can see this cabinet in the background sometimes

You can see in this picture Egnater M4 Preamp in Brad's rack.

You can see in this picture Randall RT2/50 Power Amp in Brad's rack.

According to Guitar Geek, Brad used Mesa Boogie Rectifier 4x12 Traditional Straight cabinets.

At 0.23 in the video "Linkin Park - In The End (Live 8 2005)" by Live 8, four Mesa/Boogie 4X12 Recto Standard Oversized Slant Cabinets are visible behind Brad Delson, confirming his use of this gear during the performance.