How to avoid hum and hiss to speakers from amps.

If you are already experiencing this, you've got one of what could be many problems.

1) Tubes could be bad or going bad

2) You've got ground / AC polarity issues or very noisy AC mains

3) You are picking up higher than average quantities of RFI or EMI

4) The gain of the system is TOO high

5) The equipment is poorly designed i.e. very low signal to noise ratio.

As a side note, if you've got audible noise of any type coming through the speakers at or slightly above normal listening levels, you'll never achieve the results that most "audiophiles" desire. Without a black background, you lose detail, dynamic range, imaging is not as vivid, notes are blurred, etc... It is not abnormal to have a VERY small amount of audible hiss coming out of the system with the gain cranked wide open. On a good system, you can put your ear to the speakers with the gain wide open and barely hear any noise at all. Just don't forget to turn the gain down before playing some tunes : ) Sean
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I agree that using tubes with very high sensitivity speakers can make for a noisy system. Tube based systems typically have higher gain and ANY noise that is generated is easily reproduced through the higher than average sensitivity speakers. Havng said that, i've had systems that were VERY quiet with speakers that were rated at 104 dB's @ 1 watt. Like anything else with audio, you have to work at it. Sean
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