VC4Ever":3tf8riml said:
A converter is really just sampling the analog signal to digital and vise versa. The sample rates are pretty much industry standard yes?
I think I agree that the mic pre would make more of a difference than analog to digital conversion. The mic pre colours the signal and the converter is just sampling the wave.
Ideally a converter's job is to accurately sample the signal. Inconsistencies happen for various reasons though, including: the components used, the circuit design and its layout. I wouldn't say that all converters these days are great, but it's a lot easier to get a very good converter in an inexpensive audio device (including some PC mainboards) than ever. I had said 20 years ago it was a very different story, but even 10 years ago it still wasn't nearly this good.
There are a few few things about inexpensive audio devices which can make things crummy. For those which have built in mic preamps, the "line in" often passes through the mic preamp (but padded to reduce the level). If the mic preamp is "super clean", you're running in its linear range for the line in, so it doesn't matter much. But if the preamp has some coloration to it, that's added to a "line in" signal just as much as the "mic in" signal would be. Jitter is apparently an issue sometimes (although I don't know I've experienced an issue with it, that I'm aware of). Headroom of the preamps, as well as how well their "instrument input" works, is another common issue; some cheaper devices clip easily (they're not really set up for strong DI signal from guitar, or the mic preamps just have low headroom in general for everything) or they don't provide much mic gain. Headphone amps on some of these units are really low output (Scarlett 2i2 for instance) and in that case you might have trouble monitoring what you're recording if the sound outside your headphones is loud (if the amp, drums, etc. just drown out what's coming from the headphones). Then there are the issues that can happen with drivers, compatibility...that sort of thing. Oh and for higher sample rates, a lot of devices have IMD at those sample rates (although most people don't test for IMD and some might actually hear IMD as "something special in the high end" if it's not too prominent).
As for "adding color" to a "super clean mic preamp" signal later after it's recorded (as Revson mentioned

that's definitely an option. If I'm being really picky though, I'd say imitating what a preamp does to the signal isn't really quite the same thing. You can approximate most aspects of it, but I haven't heard it "nailed". Comparing what a recording done with a Neve (or similar design) mic preamp with transformers on input/output sounds like, to one that is recorded by a "super clean" mic preamp and later is colored with a plugin, doesn't sound the same to me. I've tried and gotten pretty close on some attempts, but it's involved a few plugins doing different things and dynamically changing based on the signal content/level...so I'd save that as an effects chain, and try it later with a different recording...but then it doesn't have the same effect and I have to readjust everything.

It's a lot faster for me to record with a preamp I like, hearing the signal once with headphones as I place the mic, than to color a "super clean mic" signal later to sound similar. For that matter if I'm using a "super clean" mic preamp, it's faster for me to choose a mic that works with it for the sound I want instead of coloring the signal later (so that's another equally valid approach).
I should also mention that in terms of quality mic preamps, things have come far in the last couple decades, similar to converters. If you want something like a Neve or API there are more options than before. Also you don't "need" a Neve or API (etc.) to get very good recordings. Some of the "cleanest" and simplest mic preamps sound quite nice. Using one of those, I'd just pic a mic that works best for whatever I want from it (and sometimes it's not the "industry standard" that I'd pick, but just the one that gets the sound I like best). For more articulation with silky top end for instance, try a cheaper condenser that has limited frequency response (even one with "higher noise", since by comparison to a dynamic mic it's still going to sound relatively quiet); I like the Audio Technica 2020 for that job. Or for that matter, some of the newer dynamic mics with neo magnets like Samson Q7; a mic like that with most common mic preamps sounds pretty good to me for guitar.
Then when considering the context of recording electric guitar: we really have it easy now. We're not recording grand pianos in well-treated rooms and trying to capture a lot of subtlety. Most times it's 1 or 2 mics pretty close to the speaker of a guitar amp. With "decent" mic preamps and "decent" converters these days, you're set. Very few (overdriven, "heavy") electric guitar recordings done with "the best" converters and "the best" mic preamps sound different in a particular way that can't be accomplished similarly with less expensive converters and mic preamps (and possibly using plugins). And sometimes what's so "special" about a particular mic preamp is just how ringy it is at a certain frequency at a certain level (which can be imitated by automating an EQ); that "special greasiness" is actually not hard to attain.
I'd just still say in terms of what I find important, converters have fallen to the bottom of the list. That's only because in general it's easier to get good sounding converters these days, in lots of devices.