Trying to reduce noise while listening to tube phono


Let me start by staying that I'm in love with how my system sounds right now. Hagerman Trumpet and Decca London Super Gold (paratrace stylus) is a ridiculously good combo. The only "but" is that if I raise the level to 3 o'clock on the preamp (Herron) I start to get tube hiss... or some hiss from somewhere. It used to be worse but then I got all new very low noise tubes and it improved a ton but I want to see if I reduce it some more. I'm wondering if the issue is the amount of gain on my preamp? Should I try another preamp with more gain and see if that solves the problem? On other inputs there's no hiss even at full volume so there's nothing technically wrong with preamp.
dhcod
Tonearm leads. Mine are very fine non shielded cables that run from headshell to RCAs. I really should have realized this a while ago.
So we got lucky. And thanks to mijostyn learned something about tube rush as well. Glad I was able to help.
That's why. What is the reason to have unshielded tonearm leads?
The first tonearm I had was an ADC Pritchard. It came with the Thorens TD 124 that I bought use. It was a wood tonearm and the wire within the arm was unshielded. As the arm got closer to the motor the hum increased. This all disappeared after I put an SME on it. Unless there is something special about that wire I would consider rewiring the arm. If there is something special about it I would love to know what that is!