Very Simple Preamp

Hi,

Not long ago I finished my poweramp based on the Lm3886 chips.
But with this design a lack a preamp, so i juste put the volym pot on the input lines to my poweramp.

If my signal is very weak, am I missing out on some effect?
For instance if i amplify the signal from my computer which isn't a very powerful signal source.

And if this is the case i would be interested in building a very simple preamp in a seperat housing. The input impedance is
10K Ohm.

Any suggestions are very welcome,
Best regards/
Christian V