Generally the standard plugins you would find in your mastering chain are (in this order):

EQ (for sorting out any rumble, and fixing up the final mix frequency-wise)
Compressor (For bringing up the quieter sections inbetween your BIG transients i.e. kicks and snares) - normalizes the waveform slightly
Limiter - For making sure that the track peaks at 0db - also a form of compression

What would be important is to listen to other songs on the monitors that you are using to adjust your EQ and limiter accordingly.

Hope this helps.

ones mans shit is another mans aphrodisiac

if its gameboy music, record each channel seperately. then whack it in a DAW like ableton, or pro tools if you is pro. much easier to mix it down better then. personally i dont do this, i figure it comes from a gameboy so its supposed to sound a little shit right : P

Using the retro software that many of us do, we don't have the option of EQ'ing every channel, and there will be parts of the mix which will sound often muddy because of this.  There are some frequency bands which aren't useful, and some which normally aren't nice, so mastering can be used to tone them down a bit.

Also, years ago we used to run stuff through a Vitalizer, it added stuff like high end, er, sparkle, stereo widening, bass harmonics and just made everything sound, well, better and louder and warmer.

That's what mastering should be about.

for me LSDJ is always LOUD AS FUCK anyway

i do it all the time for my lsdj tracks. a little of lv2-ir plugin doesn't hurt either.

Usually (when i record analog music) for mastering I use Ardour + Jamin, but I've never tried it with LSDj tunes. The only "mastering" that I do on LSDj tracks is clicking "Normalize" in Audacity, for now I like to keep it raw

Hold on my gameboy's warming up..

I modded my DMG with two 6L6 Russian winged Cs tubes to really get some warmth out of my wave channel.

this is kind of off topic but "mastering" for today's tracks is usually making them work (and sound professional) when played against other records within the same genre and matching volume levels from track to track on an album and sweetening up your final mixes for consistency between them. The thing mastering engineers are doing most of the time is mixing stuff for radio/release so that you're not adjusting your volume level for every song. Something that is also handled in radio land by adding a limiter (which is just a compressor with settings 6/1 or above) before broadcast....many people in studios now release 2 masters one for playing in your home and the other for radio (with dialed back compression so as not to sound squashed on the radio).

This meant that the entire endeavor is subject to the loudness war, given that most records are overcompressed and clipped now.

On ardour, I use on a final mix of a recorded LSDJ  song. (I prepare a really good mix on the DMG before recording).

then

Fast Lookahead Limiter
TubeWarmth
Calf vintage Compressor

that's it.

Alright, I'll give audacity a try.   Sounds like what I'm looking for.  Thanks!

About the software I'm using, it's Garageband. ( Please don't laugh )

o yea lol

ozone is only for brostep yo

https://neon1.net/prog/normalizer.html
OR
http://normalize.nongnu.org/

this is all the "mastering" i do. it does boost the sound that an audio program exports (usually) but it doesn't affect the sound otherwise from the volume. maybe it's not what your looking for (it's what i think you SHOULD be looking for!) though

i heard "izotope ozone" was the best for loudness war mastering