I play my electric guitar through an amp (actually a bass amp). I am looking for a distortion pedal and am curious as to where to place it: In front of amp or in FX loop, and additionally do all pedals work fine in front of the amp vs effects loop? I'm asking cause my amp does not have an effects loop. I've been watching reviews of different pedals and for example the boss mt-2 sounds weird from the front but when played from the effects loop, it sounds amazing.
The chain is guitar > pre-amp > power amp> speaker.
Putting any effects here - Guitar> fx > pre-amp > power amp > speaker means that the pre-amp (tones mainly) will affect the fx.
Putting any effects here - Guitar > pre-amp > fx > power amp > speaker means that the fx are subjected to whatever settings the pre-amp has.
Modulation, delay, tremolo are usually in the second scheme, and most others are found to work better in the first scheme. Having said that, it's very much down to personal choice, along with what amp. and guitar and effects are being used.
Some pros will have their board wired so that some go on one route, others the other way, and most switchable for changing. Gets a bit complicated, with extra cables, etc., but gives the flexibility they need.
Whatever works better in your situation is what you will sort out - some distotion pedals work better one way than the other. Only you know what sound you prefer, so experiment. Be aware that the vol. pot. on the guitar as well as all other settings on the amp will have an effect on the overall sound.
Better is subjective, the pedals will sound different when sent through an FX loop than direct. The difference is where the distortion is created in the amplification chain.
There are two types of effects loop, parallel and serial which will have different sound and application also.
An effects input in an amplifier is usually after the pre-amp stage of the amp, so the effect is getting applied to a clean, boosted signal from the guitar, giving you more signal and tone to add distortion to.
The pedal directly from the guitar is distorting the guitar's low level signal and sending the distorted signal into the pre-amp of the amplifier which then makes the distorted signal louder.
You can get a similar sound to using an effects loop by having a clean boost or a signal buffer pedal in chain with your distortion pedal.
While better is of course subjective and there are exceptions (yes you are right about the MT-2 Metal Zone that is the ONE 'dirt' pedal aside from a few 'few amp in a box pedals' that tend to work better if you plug input direct into them and then take output into the fx return bypassing the preamp completely. I wouldn't say its horrible in front, but it gets a bad wrap because most people dial the settings poorly although a few component changes can make it sound real good... check out Colin of CSGuitars videos on youtube about the pedal) 99% of the time you put tone effects in front of the amp and time based effects in the fx loop. Look for "perfect pedal order" by Steve Vai on YouTube for example. He is a certifiable expert.
The main exception to this is if you are getting your entire distortion tone from pedals in which case you can start putting things like the chorus pedal after that but in front of the amp... ultimately you can do anything, but if you are using a distortion circuit / tube clipping in the preamp it will be applied to your modulated signal which is usually not what you want, and in the case of delays and reverbs likely not what you want ( since the softer repeats and reverberations will likely barely be distorted and sound almost clean compared to fx loop were you are repeating and reverberating a possibly heavily distorted sound)
In a nutshell : mono/poly/harmonic octave generation, wah, compression, fuzz, distortion, od, boost, eq, and for many a phaser will go in front often in that order.
Chorus, possibly phaser, flanger, tremolo/vibrato, delay, reverb will come in the fx loop. The order is not as clear here other than that delay and reverb are generally last and in that order. but there's a lot of choices here and variants as people perform modulation on the delays.
Insert volume pedals where ever you like many different feelings on that. Some people have multiple so they can alter delay volumes as well as input volume first (instead of from knob on the guitar)
I'm honestly not sure where one puts a ring modulator and some of the wacky synth stuff but I presume that falls under the same category as octave generators where you send a in a clean signal to it. but I don't have that problem to deal with lol
thats a pretty good guide for a beginner, once you start to embark into stereo, multiple amps and such things start to get more complicated but again the rules still generally apply and almost become stricter as you might have a split going on in the FX section where the main amp is dry and the 'wet' mix goes entirely into the FX return of another amp so that the combination of signals doesn't overwhelm your power amp or generate unintended power amp distortion, stereo chorus often puts original signal to one and effected signal to the other, delays can be ping ponged back and forth for stereo movement or kept entirely on a seperate wet amp, similar for the other effects.
more of note is that using bass amp your upper frequency sound may or may not sound good. the quintessential guitar amp design by fender was actually a bass amp originally so its not unheard of, but if you aren't downtuning a lot you may find guitar amp suits you better than a bass amp. this of course has no impact on your question though