the key to the good brass sound is the attack. how do you get that breath effect?
use 2 saws, slightly detune them, make sure you dont have sync enabled. open up all the VCF and the VCA filters at first. just make is buzz away to start off.
the key is that you need to assign an envelope to the semi pitch of one of the oscillators. i usually use osc 2. connect the envelope to the semi pitch parameter of the 2nd oscillator and then its a case of making adjustments to the amount of the envelope modulation and the decay parameter of the envelope. all synths a different as they have different envelopes but the key is to get the envelope decay and the envelope amount just right where it sounds like brass.
no matter what synth is it, i start off with the envelope at
fastest attack, 1/2 way n the decay, no sustain, no release, full negative fade if you have it.
usually a very small envelope modulation i start with.
i keep tweaking the modulation amount and the decay until your transient sounding brassy. each time you add more envelope amount, move the decay back to smaller figures and gradually increase while trapping a single note on the synth.
if you keep playing with these 2 parameters eventually you will get it nailed.
You need a nice chorus for this kind of patch to sound 80's.
most VA synths or analog with assignable envelopes can do this kind of patch. predator is great for this in the VST world and i know it works. but im sure there are endless plugins that will do it.
if you want it to sound exactly like those records..... then try these keyboards...
Korg DW8000, Jupiter 8, ob-8, matrix 12, ensoniq SQ80 or ensoniq ESQ 1, yamaha an1x, Nord Lead, Nord Wave