The max gain of the Parasound is probably higher than ideal for the pre-amp, so try turning it down via the gain knobs on the back of the amp (nice feature!).
Speaking for myself, it's OK if I can discern the hiss at the listening position when flipping the mute switch on and off, but I don't want to be made consciously aware of it, if that makes sense.
The audibly crackling tube needs to be replaced if the noise persists.
BAT ships the basic 3iX with very quiet Electro-Harmonix 6922EH tubes (these also come in a version with gold pins, which I don't have any opinion about). Mine also shipped with J/J 6V6 tubes (the 2 bigger ones). I'm not sure how much the 6V6 contribute to the hiss.
"The Tube Store" has a convenient 3iX tube replacement package with all Electro-Harmonix tubes for $90.
You could also try Jim McShane (mcshanedesign.net), who has a very good reputation with tube users. Explain your situation, and he can select the quietest tubes for you.
Speaking for myself, it's OK if I can discern the hiss at the listening position when flipping the mute switch on and off, but I don't want to be made consciously aware of it, if that makes sense.
The audibly crackling tube needs to be replaced if the noise persists.
BAT ships the basic 3iX with very quiet Electro-Harmonix 6922EH tubes (these also come in a version with gold pins, which I don't have any opinion about). Mine also shipped with J/J 6V6 tubes (the 2 bigger ones). I'm not sure how much the 6V6 contribute to the hiss.
"The Tube Store" has a convenient 3iX tube replacement package with all Electro-Harmonix tubes for $90.
You could also try Jim McShane (mcshanedesign.net), who has a very good reputation with tube users. Explain your situation, and he can select the quietest tubes for you.