#1
Okay. I have a Epiphone Les Paul Standard. Vox Valvetronix 30 watt. Digitech RP300 and Boss DS-1. If I play with some distortion with the Rectifier setting, I get this annoying high pitch hiss. Why is this? Am I too close to the amp? Should I turn off some electronics in my room? Trash the amp? New guitar? New effects pedal?
Electric:

Epiphone Les Paul Standard
DigiTech RP300
Boss DS-1
Horizon cables

Acoustic:

Silvertone D09

Other stuff:
Dunlop .88, .60, .50 picks
GHS Fast Fret
Franklin strap
Dunlop Straplok System
#2
Operator error? Amps hiss. Adding a distortion pedal into the mix adds more hiss. If what you describe is feedback,lower the distortion and move away from the amp.
Bhaok

The following statement is true. The proceeding statement is false.
#3
It mainly happens when I mute the strings. Like simply just putting my hand over the strings...
Electric:

Epiphone Les Paul Standard
DigiTech RP300
Boss DS-1
Horizon cables

Acoustic:

Silvertone D09

Other stuff:
Dunlop .88, .60, .50 picks
GHS Fast Fret
Franklin strap
Dunlop Straplok System
#4
Option 1 then.
Bhaok

The following statement is true. The proceeding statement is false.
#5
I think you're too close to the amplifier.
The distortion pedal doesn't help matters, either.
Ceci n'est pas une signature.