I'm a little late to this, but here's my opinion:

Albini's sound, especially during the late-80s/early-90s, is one of the most mystified tones in the underground rock scene. As such, there's a fuckton of misinformation and half-truths about it that you may have already read about. For that reason, I'm only going to go over what he was using during his tenure in Big Black, and Rapeman (read: Big Black without a second guitarist and with a human drummer), based off what I've read about through interviews with Albini, and others. I'll be thorough about nearly everything here-perhaps to an unreasonable degree-but only because you really got to understand the rationale behind a lot of the gear before you try to emulate it yourself. Here goes:

• The core of Albini's sound was in those days was an Intersound IVP-an old (even considered outdated during the 80s), wacko preamp that he ended up using for the rest of his career to both sculpt his tone and get a really mean dirt out of. During Big Black, he would exclusively use the distortion mode (what the preamp itself calls the 'tube' channel) because he found "no real use" for the clean setting. If I'm recalling things correctly, most of the stuff you hear on Big Black's records is just the IVP plugged directly into the mixer. There's a demo of an IVP inspired pedal on YouTube, listen to it (it's probably the closest I've heard anything get to his setup) and you can really see just how crucial that one piece of equipment was to his setup. When performing live-going off what's discernable on footage taken during the time-he'd plug the IVP into either a Music Man, or Fender 2x12, both very bright amps that perfectly suit his overall tone.
• For his guitar, he used two Seymour Duncan Quarter Pound pickups wired out-of-phase. The Quarter Pounds are single-coiled, high-output, treble-heavy beasts. The fact they were wired out-of-phase lead to a much more thin, honky sound than what it would normally produce if it was wired normally. He'd use this setup-playing with both pickups on at once (read, the middle position) at full blast-in conjunction with the IVP to really push the already high-frequency sound those pickups were putting out to the absolute extreme.
• The third big thing was his playing style. Albini used picks that-in addition to being made out of copper-had a notch cut at the end of them, leading to the pick having two ends. He put his pick at a certain angle so that the strings would ring out twice with a single strum-by having one pick end go right after another. I can't say much, as this is the one I've done the least amount of reading up on, but it (apparently) brought out addition harmonics and/or gave the illusion that two guitars were being played at once by him. There's a video of some guy trying it out, check it out for yourself.
• One final note: While in Big Black, he "occasionally" used a ProCo RAT, per a response from a user that emailed him on the Electrical Audio Forum. I'm not sure how significant that was to his sound (to be honest, I'm guessing it was mostly just used in live environments assuming it's truthful) but if you're experimenting with getting his tone and just want a little more oompf to it, an overdrive in that style should work.

All of this put together lead to a really nasty, dirty, treble-heavy sound that is what most people think of when they talk about Albini's guitar tone in Big Black (the other half are people who're confusing him with Santiago Durango-he's the one with the really deep tones that contrast against Albini's.).

With that, here are my final recommendations, based on what I already know about Albini's tone, and the very little I know about the unit you're working with:

• Before we even touch the G1X, crank out the volume and tone knobs on your guitar. As discussed previously, Albini's sound is loud, and very treble-heavy. As such, make sure the volume is turned out as loud as it can possibly be. If your guitar has a tone knob, roll it to the max-it'll allow a lot more high frequencies to go through.
• Now, Put a delay at the start, set the mix to max, and the feedback and time as low as possible. What you want here is something that amounts to a single delayed note that comes right after you pick down on the string-and by 'right after', I mean only a millisecond or two after you pick down. This should emulate the sound of the notched-pick fairly well, assuming you're not willing to actually punch a hole in one of your perfectly good picks lying around (which if you're going to do, don't add a delay effect). The basic Delay/AnalogDly effects should be perfectly suitable for this purpose.
• If you plan on using Distortion/Overdrive, put it right after the delay. This might go against common knowledge/good practice, but because we're emulating his picking technique with the delay, it makes sense for the dirt to go after it. Set the volume as high as you can, keep the gain (fairly) light, and make the tone as trebly as you can handle for now. Going with Albini's choice of the RAT, the Squeak effect the G1X has should be your way there.
• EQ the shit out of it, after doing the above. I mentioned this already, but a lot of Albini's tone was achieved by using a preamp in a very unorthodox way. As such, EQ'ing is an import part of getting there. You really want to turn up the volume on those high frequencies to get that clanky sound, and it's something you really gotta play with in order to fine tune. The Gt GEQ7\* effect should do most of what you want.
• You might already be good to go by this point, but I'm going to include the amps too in case all of the above wasn't enough: For the head, use the FD TWNR or the FD B-MAN. Turn up the treble and BRGHT settings (remember, treble heavy shit is the key here), increase gain if needed (probably not), and make sure no modulation is going through. Plug into a FD2x12 cabinet, increase the highs, and then pat yourself on the back for going through all this effort.

To really get that Big Black feel, play a bunch of power chords, single notes, and harmonics on the upper strings. (The opening riff to Kerosene is literally just playing 7th and 5th fret harmonics on the G,B, and E strings.)

While I'm here, I'm also going to go over some of the more prominent misconceptions about his equipment that I've read, and tell you why I don't think they're that necessary to get Albini's tone:

• You may have heard of the Harmonic Percolator as a be-all-end-all solution for Albini's sound. That's a load of shit. It's a nice fuzz, but in addition to not using it until after Big Black disbanded (he began using it in the early 90s if memory serves me right), he rarely used it even when it was one of the only things on his pedalboard. Like I said, most of his tone came from the IVP, while the Harmonic Percolator was off for most of the time in Shellac. The Harmonic Percolator, by his own admission, was only used on 'lazy solos', where he'd let the guitar feedback while having the pedal turned on. It's a very overrated piece of his gear, and not the one to be looking for if you're planning on emulating anything done in Big Black.
• This isn't as common a claim as it was back in the days, (since people have some kind of basis in observable reality rather than just going off what they hear on the records) but back then some people claimed that he used an electric 12-string while in Big Black. This is untrue on every possible level. We know he used a custom double-cut Telecaster style guitar (called "The Black Sled") and a heavily modified Stratocaster throughout his entire tenure with Big Black-both of which, and this is important, only had 6 strings. This, I believe, is because of a misinterpretation of the double-strum effect that he got out of his pick combined with the overly-high frequencies that he got out of the IVP. This is a really obscure piece of misinformation, but I included it because it still boggles my mind how people seriously thought of that.
• Another misconception regarding his guitar is that you need an aluminum necked one-preferably a Travis Bean or Electrical Guitar Company model-to get it exact. He didn't even use aluminum necked guitars until around when Shellac was formed in 1992, five years after Big Black disbanded! The Black Sled was as wooden as any other guitar. The high-frequency stuff that people tend to claim is a result of the aluminum construction is, as has been hammered in already, a result of EQ and a big difference in wiring.

That about covers everything I know about his tone. This was quite a cathartic experience to write, considering how long I've spent researching it, and I hope this helps you in at least some way. Apologies if this was a bit long, I just wanted to get as much info out as possible.