Tubes hiss. I don't know any solution for that.
Regarding Hum...It is possible to make a tube preamp that has no hum (well almost).
My first preamp was a Heathkit (which I understand was basically a Fisher design). It was quite difficult to build because it had lots of twisted wires, some of them running inside spring-like metalic shielding. It humed.
My next preamp was a dyna-kit. It had DC filiament power for the tubes. The whole design was much simpler that the Heathkit, and performance was superb. There was not a single piece of twisted or shielded wire in the unit. It did not hum.
One thing that we used to do to minimize hum in tube circuits was to open up the chassis, turn up the volume so that hum was audible, and take a grounded wire and try contacting it to various points in the circuit that ought to be ground. Be careful not to short out any hot points!!! Sometimes this trial and error method of optimizing grounding gave a significant improvement. "Dressing" (relocating) the internal wires can also help (or hurt).
Regarding Hum...It is possible to make a tube preamp that has no hum (well almost).
My first preamp was a Heathkit (which I understand was basically a Fisher design). It was quite difficult to build because it had lots of twisted wires, some of them running inside spring-like metalic shielding. It humed.
My next preamp was a dyna-kit. It had DC filiament power for the tubes. The whole design was much simpler that the Heathkit, and performance was superb. There was not a single piece of twisted or shielded wire in the unit. It did not hum.
One thing that we used to do to minimize hum in tube circuits was to open up the chassis, turn up the volume so that hum was audible, and take a grounded wire and try contacting it to various points in the circuit that ought to be ground. Be careful not to short out any hot points!!! Sometimes this trial and error method of optimizing grounding gave a significant improvement. "Dressing" (relocating) the internal wires can also help (or hurt).