Mike Dirnt's bass strings: the Green Day Precision rig, sourced
Reviewed by the Change Your Strings editorial team · last verified .
Mike Dirnt plays Fender Super 7250 nickel-plated-steel roundwounds (.045–.105) on his fleet of vintage Fender Precision Basses, primarily 1963–1974 ash-body P-Basses with the occasional pickup swap to Seymour Duncan Antiquity. He's the founder + bassist of Green Day, signed to Fender as a signature artist with the Mike Dirnt Precision Bass (originally launched 2004, now offered as the Mike Dirnt Road Worn). Dirnt has occasionally noted Ernie Ball Hybrid Slinky Cobalt as a secondary set for specific tones.
Who Mike Dirnt is
Mike Dirnt (Michael Ryan Pritchard) is the founding bassist of Green Day, California pop-punk-into-arena-rock trio he formed in 1986 with Billie Joe Armstrong, completed by Tré Cool on drums in 1990. Green Day's catalog from Dookie (1994) through Saviors (2024) is one of the most commercially successful in punk-adjacent rock, Rock and Roll Hall of Fame inductee in 2015, multiple Grammy wins, and the American Idiot (2004) era that crossed Green Day into Broadway rock-opera territory. Dirnt's bass is the locked-pocket foundation underneath Armstrong's downstroke rhythm guitar.
What he plays
Fender Super 7250 nickel-plated-steel bass roundwounds (.045, .065, .080, .105) on a fleet of vintage 1963–1974 Fender Precision Basses, plus his signature Mike Dirnt Road Worn Precision Bass. The signature P-Bass, originally released 2004 between Warning and American Idiot, is one of Fender's longest-running bass signatures.
He has noted using Ernie Ball Hybrid Slinky Cobalt strings for specific tones, but the Fender Super 7250 is his documented standard set across studio and live work. Some of his vintage P-Basses have had stock single-coil pickups swapped for Seymour Duncan Antiquity humbuckers, a higher-output upgrade that fits the dense distorted-bass passages on American Idiot and 21st Century Breakdown without losing the P-Bass voicing.
Why this fits the rig
A Precision Bass with nickel-plated-steel roundwounds in standard .045–.105 is the canonical pop-punk bass voicing, punchy mid-range, P-Bass split-coil bark, just enough top-end roundwound brightness to cut through Armstrong's downstroke rhythm guitar without veering into Rotosound stainless territory. The .045–.105 standard gauge is also factory-spec for Fender P-Basses, which means Dirnt's setup and his guitar tech's approach can use stock Fender setup specs without exotic gauge accommodations.
His technique, per his own description, "I move my arm a lot, but my sound really comes from my wrist", favors steady eighth-note pulse with melodic fills, exactly the role pop-punk bass occupies. The Super 7250 set's tension envelope supports both the locked-rhythm foundation and the more-melodic passages on Holiday / Wake Me Up When September Ends / Boulevard of Broken Dreams without needing a gauge change between songs.
Related
- Green Day
- How often to change strings, touring cadence