If it’s loud it doesn’t sound normal they are high gain pedals so you may get some noise from your pickups, leads etc or a little hum when not playing or standing facing and too close to your amp there are several things that can cause noise
Check your grounds are all good and your audio wires don’t run paralell or close to your power and ground wires If you have to cross them do it like this +
You can also get unwanted noise amplified through the circuit with cheaper power supplies that aren’t regulated or filtered
The ratt circuit does have power filtering the 47u C11 check C11 solder joints are ok
There’s also the possibility of DC leaking into the audio path as I say several possibilities