The Mars Volta's Juan Alderete
During the band's 2011 tour, Alderete chose to use his 1970 Precision fretless bass—the bass left the Corona, CA, with the fretless neck—for much of The Mars Volta's shows opening for Soundgarden. Alderete preferred the fretless with flatwounds—always Ernie Ball 2806 Flatwound .045–.100—because it's warmer and more musical with the flatwounds and lends itself to a better overall tone when combined with instrument's fretless neck and his abundance of quirky sounds emanating from his board. Two mods that were done to the bass before Alderete acquired it included a Stars Guitars brass bridge and a Bartolini single-coil in the bridge position giving the bass a P-J hybrid setup. The only modification he did do the bass was adding the Hipshot D-Tuner. His other two main basses for this run include a '64 Jazz bass and a '77 Precision that is modded with a P-J setup like his '70 P.
Amps and Cabinets
Just before heading out on this 2011 tour, Alderete switched his amp setup from his old standby SVT-VR heads and cabs to the newer PF-500 heads, which power PF-115 1x15 and PF-210 2x10 cabinets.
The TMV bassist is a big proponent of using compression on his tone—no doubt because of his love for Jaco—and has used a Boss CS-2 Compressor/Sustainer since his days with Racer X in the '80s. He says he leaves this pedal on probably 95 percent of the time because it adds some roundness to his high end. He's stuck with this retro box because it's the most musical compressor he's ever played. Next up is the Boss VB-2 Vibrato that he uses to accentuate and pop his harmonics out in the mix. And the third Boss pedal on his board is the OC-2, which he feels adds dimension to his tone while retaining musicality and still sounds like a bass guitar. For straight-ahead delays and ambient verb sounds, he kicks on the EarthQuaker Devices Ghost Disaster. To push his amps to near destruction and rattle the stage, cabinets, and rafters he calls on the DOD Meat Box FX32. For water-like phaser tones he goes with the Pigtronix Envelope and Rotary Phaser, which he loves combining with a sped-up VB-2 to create a choppy wake of noise. For modulated, tweaked-out delays and sampling abilities Alderete relies on the Line 6 DL4. And the other pedals on his board that are used for soundscape, interludes, and backups include a TC Electronic PolyTune, Wren and Cuff Tall Font Russian Fuzz, Boss PN-2 Tremolo/Pan, and a DigiTech PDS 20/20.