http://www.muzique.com/lab/sat2.htm (site très intéressant !!!)
http://www.muzique.com/lab/tclip.htm
http://rezzonics.blogspot.fr/2014/01/germanium-diodes-vs-schottky-diodes-for.html
http://www.generalguitargadgets.com/how-to-build-it/technical-help/articles/design-distortion/
http://www.diystompboxes.com/pedals/diodes.html

C10 = 15nF (++) / 22nF (moins définis)

original : 6.8k, si valeurs supérieurs on à + de treble ou basse
R16 (bass) = 8,3k
R17 (treble)= 3.8k

original : R9=22 R6=100k
R9 (gain) = 1k > 33 Ohm
R6 (bias) = 150k > 82k

ajouter
CX1 = 100nF en // à C4
DX1 et DX2 =1N914 tête bèche entre CX1 et C4

http://www.diystompboxes.com/smfforum/index.php?topic=83889.0
https://reverb.com/news/simple-boss-pedal-mods-changing-from-stock-to-rock
https://www.premierguitar.com/articles/boss-ds-1-mods-1
http://www.muzique.com/news/fat-mod-for-the-boss-ds-1/
http://www.simonthemagpie.com/circuit-bending/guitar-pedals/boss-ds1-distortion-34264868
http://www.pedalhaven.com/two-easy-boss-ds-1-distortion-pedal-modifications/
http://www.ednpllc.com/boss-ds-1-flex-pro-mod.html
http://pdfelectronics.com/the-ultimate-boss-ds-1-mod/
http://www.diystompboxes.com/DIYFiles/up/Build_Your_Own_DS-1_Distortion.pdf

http://www.effectsbay.com/2016/01/guest-post-boss-sd-1-modifications-to-a-timeless-classic/
https://www.premierguitar.com/articles/5_DIY_Mods_to_Perfect_Your_Ibanez_TS9_and_Boss_SD-1?page=4

http://www.coda-effects.com/2015/11/big-muff-mods-and-tweaks.html http://www.bigmuffpage.com/Big_Muff_Pi_versions_schematics_part3.html