I record quite a bit, and I play all the bass on my stuff.
Lemme start by saying, for me, there is overdrive (like a TS8 or Klon-type at about 50%), there is distortion (like a good heavy amp or even a Muff or Rat at 50%) and there is fuzz (like that amp cranked, or a Muff or Rat at 90%) and then there is noise (like a Rat or Muff at 100% into each other, and/or a cranked amp). You will note my use in the parenthesis of “50%”; that is because overdrives can become distortions or even fuzz when cranked, and distortions and fuzz pedals can be sweet overdrives if turned down and mebbe played softly.
When I look for a fuzz bass sound my typical approach is to get it with a combination of pedals, and touch, with little compression and EQ.
I have used plug-ins, and parallel tracks/processing, and it works, but those approaches are usually the result of mix decisions where already-recorded tracks need fuzz.
So I start with the bass, which is usually just what I feel like playing. That said, I don’t like fuzz on fretless, or A/E or even flat-wounds – I prefer a good fret sound.
And generally, I prefer humbuckers with fuzz – I play alot of Hohner headless, but also a Fernandes and an Alvarez with HB’s. Fuzz is OK on my P, also, but I just like the thicker HB sound.
Me, I record through two chains to separate tracks at all times. My The Brick to a dbx160XT is slightly brighter and more detailed than my VC3Q, the latter is also more colored and dark. I blend them in the mix, often slightly panned apart.
For fuzz bass, then, my next decision is whether it’s all DI, 1/2 DI or all through the amp. Lately, it’s all through the amp. My recording amp is an Ampeg BA108 which is 20w. with an 8″ speaker, which I believe helps a bit to fit in the mix with less EQ than my 12″ or 15″ bottoms (through louder heads -altogether different with different issues in recording, starting with volume.)
I like LD dynamics on bass, lately I have been using a Peavey 520i which is like a slightly brighter SM7b.
OK, a bucker bass into that chain. For fuzz, I use a pick which, along with frets, gives a better note definition. I like softer, thin picks and use them almost always, but a harder, thick pick can make a difference depending on the gain used.
Yep – the fuzz thing obviously needs pedals, especially when recording. (Me, I’m an idiot with far more pedals than I wanna admit. But I don’t buy much boutique, and basically only by used, so there’s that compromise.) And, of course, you can switch off the pedal to clean up for the verse, etc., much easier than adjusting the amp.
Without talking about pedal-stacking – which increases the options hundred-fold (a drive into a fuzz can be a thing of surprises, both good and/or bad, and often a beautiful game-changer) – there are some basic flavors of fuzz. For example, there is the mid-cut of the typical Muff, and the mid-boost of the typical Rat. I usually record bass and drums first and then choose guitar sounds, so I pick fuzz pedals as much for their effect on my playing. Muffs can handle slower, doomier and more single-line stuff well, but can turn to mush on 16th notes, chords, octaves, slap-n-pop, etc. which can be OK, but a Rat will help you hear that complexity better.
But then, mids-forward fuzz can get lost in the guitars if they are fuzzed (think Pumpkins) or just cranked (think Metallica). A Rat pedal can often be helped with a parallel clean track to get more bottom, but that can be a PITA.
That’s where filters can come in handy: octave filters, envelope filters (used somewhat subtly), auto-wahs, etc. can bring the bottom, or the mids, as necessary. I tend to run the fuzz into the filters. Sometimes a light chorus or flanger can help, also, if the bass needs definition.
Also, do not automatically use compression into the fuzz; you probably don’t need it at all as fuzz itself compresses.
My personal EQ approach is to pass-filter all stringed instruments (60 and about 4.5k for bass), but try not to do anything else. That said, fuzz bass is as much the pedal as the bass, so … a notch at 350-400, a boost at 900 or so are not uncommon. (I like my kick under my bass.)
FWIW, I like Bass Muffs, Wicker Muffs, the Way Huge Swollen Pickle and Pork Loin (the Way Huge pedals are like more detailed and tweakable Muffs); I also like LM308 Rats, Zvex Distrotron and Mastrotron and Wooly Mammoth (the Zvexes are like blown-out Rats with gates). And then there are distortions which can be fuzz, like the Digitech Grunge pedal (not the bass grunge) and the MXR Bass Fullbore Distortion. Actually a lot of drive pedals can fuzz out if cranked; inexpensive but worthy options include the Blackstar pedals and the EHX Nanos like the Hot Tubes and The Glove, etc. Those Nanos, including the Soul Food, are cheap, and put in front of another drive/fuzz/distortion pedal can often add clarity, as well as drive the second pedal into fuzz-land. Then there are the Tech21 character pedals – the guitar-aimed can be awesome on bass (I use ’em when I need to DI, like when the kids are sleeping), and the VT is a joy for Ampegness. I don’t use multi-effects or modeling, except the Source Audio OFD is just so damn good, especially it’s gated fuzz. (But I hate the distortions on the Zoom MS60b …)
Finally, like guitars, you often need less fuzz than you think.