STin vs Combo line in

When recording using external preamp, what is the best input ?
STin or combo jack ?
Or do they have the same behaviour ?

According to the block diagram and specifications, they do not behave the same (see also pics).
The TRS of the combi jacks use the sensitive microphone preamp with gain control after/with a fixed attenuation of 20 dB.
The TRS of the ST has no gain, but expects a line level and therefore uses a less sensitive preamp, the channel of which can only be trimmed later.
An audible “better” or “worse” will probably only relate to the noise caused by the CQ preamps.
The best way to test this is in an AB comparison with the actually connected external preamp that you want to use.


Tks for the reply.
I plan to get an external preamp.
Looking for something under 600 euros.
Either Golden Age Audio Premier PRE-73 or a kit of Sound skulptor M573.
That will be my first external preamp.