very good question, frantickromatik, maybe the guys from SA and TIF will be kind enough to answer us

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I was searching through my guitar magazines and I found an article about obtaining the tone from Dream Theater's Pull me Under using Boss pedals, and it was something like this:
1. for the riffs - Boss MetalZone MT2with Level 2 o'clock, EQ1 1 o'clock, EQ2 11 o'clock and Dist 4 o'clock.
2. for the clean part - Boss Digital Reverb RB5 with Level 2 o'clock, Tone 10 o'clock, Time 10 o'clock, Mode - Plate + Boss Acoustic Simulator AC-3 with Reverb Level 10 o'clock, Body 11 o'clock, Top 2 o'clock, Mode - Jumbo + Boss Super Chorus CH4 with Level - Max, EQ 2 o'clock, Rate 1 o'clock and Depth 1 o'clock.
I know Dream Theater isn't tech metal, but I think it's better than nothing

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PS I have 2 articles from Guitar Techniques regarding Meshuggah's guitar style, but they don't give any settings for achieving their tone, just some info regarding effects, amps and guitars used for the lessons.