Tone library / Mastodon / The motherload

The motherload amp settings — Marshall MG15FX

The Mastodon guitar tone for “The motherload”, dialed in for a Marshall MG15FX with a Ibanez PIA3761 Steve Vai. Studio version, Once More 'Round the Sun (2014)

Original rig

ESP LTD Bill Kelliher Sparrowhawk with Lace Sensor pickups into Marshall JCM800 2203, MXR Phase 90 for verse sections, Drop C tuning

Mid-gain chunky modern metal with tight low-end, aggressive upper-mids, slight phaser swirl on verses

Amp settings — Marshall MG15FX

CHANNELOD1BOOSToff

Knob	Setting (0–10)
Gain	7
Bass	4
Mid	7
Treble	7
Reverb	0
Master	6

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Guitar

PICKUPbridge TONE8 VOLUME10

Why these settings

The MG15FX OD1 channel approximates JCM800 voicing but with less headroom and a tighter low-end. Pushed mid +1 vs original to compensate for the MG's slightly scooped character. Bass dropped to 4 to keep the Drop C low-end from getting flubby through the 8-inch speaker. Original used MXR Phase 90 on verses—without a phaser pedal, play those sections clean or accept a drier tone.

PRO TIPTune to Drop C and palm-mute hard on the galloping low-C riff—the chunk comes from right-hand pressure more than gain. Roll tone knob to 6-7 during the phaser-less verse to fake some of that filtered warmth.

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These settings are for a Marshall MG15FX. ToneAdapt matches any song to whatever amp, guitar and pedals you own — first match is free.

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Song, artist and gear names are used to identify the tone being matched; ToneAdapt is not affiliated with or endorsed by the artists or manufacturers mentioned. Settings are AI-generated starting points — trust your ears.