A 1976 and a 1972 100 watt Marshall, which I used in combination with 2 cabinets of four 15 inch speaker at 16 ohm impedance. Then I run the whole thing at about 7 or 8 (btw there is no 11, it stop at 10 ) , trust me that is loud, so you can also use a Tom Shotz Power Soak which I used to put on the side forcing me to re-weld the whole thing after a while since it was getting so hot that part became un-welded. There was also a trick that I used often and it was pretty cool, is to run the only two of the four power tube, since they run in pair (push-pull), you have to take 2 and 4 out, but be really careful, it will eventually blow the tube, I mean literally, also you will need to run a powerful fan behind or making a whole on the side closer to the tube. One thing with the power soak, you will burn the main resistance that is under each tube socket, so be prepare to get space parts. I never really use effect or distortion pedal of any kind except of course for effect like echo or reverb and harmonizer which was use in the last few records, for that I hired a technicien, Richard Onslow of Amplitech, to do a modification for Piggy and I. It consisted in having a input (send) and output (return) between the pre-amp and power amp section of the Marshall, this would also add a pre-amp volume and one extra pre-amp tube, this would give us the ability to pass the distortion as clean as possible into the effect, which for the bass was not such a big deal but for Piggy's sound it was crucial, otherwise everything would sound very muddy. I later learn to do it myself since we went through so many amp, and they needed some repair on tour sometime. I remember that night in LA when a beer fell in the back of my Marshall during the show, I quickly change the fuses and up it was running again, that damn thing got so hot that by the time I switched fuse all the liquid was gone, no big deal.
The lastest setup which I still use is a Marshall 9000 pre-amp use combine with a good old acoustic 270/370 (raw and powerful) or gallien krueger 800RB or SVT, that will do the trick ok, in studio I could try a few combination and see what sound best. Then the instrument, the bass guitar, first the string, in the pass (80's) I was using Rotosound Swing bass medium gauge, today I prefer Dean Markley Blue Steel ML, they simply sound better and last longer. A new set last me about 3 shows then I simply wash them in warm water with a little dish soap, that take the fat out. In studio I change string for every five or six takes, a average of 15 to 20 minutes of playing, or until the bright sounding is gone. Yeap right! Blacky washing his bass string, I got real good at it, I think I spend more time in studio doing that than smoking pot. Then there is the Liberatore, basically it's a maple wood custom build one piece neck from bridge to head, ash for the rest of the body with EMG pick-up, I designed the shape and Mauro Liberatore created, he used to freak a little by the treatement I give them, but I love those instruments, specially the last one he made for me (1989), a five string piece, high B, not the standard low B, so I could play chord and sound more like a guitar , just bigger, I really was taller after all, j/k. We always make sure that our both sound and playing wasn't getting in any conflict in the sense of alienating each other sound, which was really the whole Voivod sound, the real magic.
At last the real secret in making that sound is how you play the bass, I used to play real hard, but precise too with a hard as hell plectrum, basically it has to sound right without any amplification, also the friction and buss is a must since it will add in the distortion level but you must work on the control aspect of it, and please sound technician, if you use a DI cut all the high frequency coming out of it, use that as a leverage and use a good mic (421-57-112) for the distortion as the main source. Finally when you think you are ready you turn on the whole thing and freak everybody next door. Careful or you will break the windows~
There it is -- I thing this tells it all, so have fun. It's pretty cool playing bass, specially when you can blast it off.
In regards of the power soak, Piggy and I both used it for quite sometime, basically until we had the pre-amp separation modification done, after that there was simply not much use for it. About the playing, yes playing real hard was my way to say louder is never loud enough. But for Piggy this was the opposite, he played with .008 string gauge and played softly, not at all like the Metallica, Slayer dudes, but more I guess like David Gilmour or Jimmy Page, perhaps! Remember Piggy learned his skills playing over records of Gentle Giants, Yes and Led Zeppelin.