When you say "breath" do you mean "volume"? If so it depends on the type of pedal, or even the specific pedal, you built. If you're building an overdrive or distortion there are a few ways to increase the volume output of the pedal... basically any component that goes to ground in a circuit is responsible for cleaving a part of the signal and leaving it for dead. The final "volume" potentiometer value may be changed, the input components can be changed to allow more low or high end into the circuit, you can increase the gain of the transistor stage, increase the feedback of the op-amp stage, etc... each will augment the total volume output a little differently.
If breath is "tone" that's also very easy to adjust and can be done in a handful of ways, including messing with RC filters, input and output caps, etc..
When you say breath I think of stereo width and the 3D stereo field.. which, if you're not proficient in the English language (no offense at all intended here!), I doubt was your intention. If that's in fact the case you'll need an expert, i.e. not me, to help you with that one... though on the whole most circuits here don't require stereo considerations, so this line of thinking is probably superfluous.
..not sure if any of this applies specifically to your pedal, so post a schematic and we can all take a look and give you more definitive advice!
In French we say "Souffle", maybe "Blast" is more appropriate. The pedal works well, the volume is ok, but there are a lot of "blast" at low volume. Only a boost pedal / overdrive. This is not the High Gain pédal.
We've got a couple of French-speaking members here and I know a bit of French myself so try posting your original question again in French and see if I or one of the others can't crack it.