dead quiet

Hum is an indicator of a problem when it manifests in a phono setup, regardless of cartridge output. When I encounter it, I try to see what the preamp does if it has no input on the phono at all; you should get hiss but no hum.

If that is not the case then you have find out why. Pick the preamp up and see if moving it changes the hum. If not, I would be very tempted to have the preamp serviced.

If the hum is elsewhere, you have a wiring problem. Sometimes hum is the result of RF intrusion into the system. This can be particularly problematic on straight tracking arms with only 4 wires- often LT arms combine the minus output of the left channel with the tone arm ground (they do this to reduce the number of wires which can cause tracking problems) but the result is a ground loop that can leave the system vulnerable to RF.

RF can be sensitive to the current position of the wiring; if you move it and the hum changes, be suspicious of RF. The preamp can be set up to reject RF so sometimes this is an indication that the manufacturer has not done their homework.

Other hum problems relate to wiring in the arm and cable. Grounding is usually the culprit- confused connections can be an issue, as can broken connections. A through check is advised.

As Atmasphere states, hum is almost always due to wiring/grounding faults. If the preamp hums without any cartridge input it is faulty...often power supply capacitors. Tube preamps that used ac filament excitation sometimes hummed, but that's why we use dc today.

Even relatively inexpensive solid state preamps can be very quiet. "Dead" is subjective. In my experience tube preamps exhibit some hiss, but this is an inherent characteristic of a tube and not under total control of the designer.

But the bottom line is that hiss and hum is almost always below the level of LP surface noise, and even further below even quiet sections of the recording. If you worry about noise that is audible only with your ear against the speaker you are exhibiting irrational audiophile paranoia.

...except that noise, hiss, hum, growling, yodeling, etc. marks its imprint on the total sound. I had a Grado Sonata in a Rega P-25 that hummed ever so slightly - I couldn't hear the hum when the record was playing. When I learned how to get rid of the hum..at least lower it, the result was much better in the overall presentation.

Atmasphere and Eldartford, great posts. When I first started dealing with noise issues in a new table rig a few years ago it would have helped me if I could have found these comments. Instead, I had to weed through the archives.

The operative comment though is:

But the bottom line is that hiss and hm is almost always below the level of LP surface noise, and even further below even quiet sections of the recording. If you worry about noise that is audible only with your ear against the speaker you are exhibiting irrational audiophile paranoia.

I've come to agree with this - but do others who have posted that "dead quiet" is possible agree too? Also, I don't think this is the same as "dead quiet".

Stringreen, FWIW the hum that the Grado exhibits in the Rega is a problem with the wiring of the Rega. It can be corrected by grounding the platter bearing and the motor to the same ground that the arm uses. I have no idea why Rega does not do this themselves but they don't.

Bdgregory, I think that the term 'dead quiet' has a little salt with it. **A lot** depends on the efficiency of your speakers- if they are 89db you will probably have to put your ear to the driver to hear the background noise, but it will be there regardless of the technology of the amp or preamp.

My speakers are 97db but I am not aware of the background hiss from my listening chair, although I can hear it when I stand by the speaker.

So- 'dead quiet' has to be taken in that context. IOW, virtually dead quiet :)