Do tweeters always noise?

[awboy]

When less then 10 cm away from any (!) tweeter I have, I hear noise from it even when the signal to a normal fully integrated amplifier is perfectly zero (short circuit).
The only time I do not hear this is when I connect the loudspeaker to a pure power amplifier and putting its volume attenuator to maximum volume. In this case there is no resistor devider in the soundpath.

What the hell is this, and why should I put up with it?

[leadbelly]

Originally posted by awboy
What the hell is this, and why should I put up with it?

You really should describe the "noise" in more detail; it could be several things that would each sound different. Without any other description, I will take a guess and say the noise is from DC offset present at your speaker terminals. Try putting a large cap in series with the tweeter and see if that cures it.

[Richard C]

Since the tweeter already has a capacitor in series with it what effect would adding another one have?

[leadbelly]

Originally posted by Richard C
Since the tweeter already has a capacitor in series with it what effect would adding another one have?

I had assumed he was talking about connecting the tweeter directly to the terminals.

[sreten]

The simple answer is noise is always dominated by that
produced in the preamplifier for any power amplifier with
a remotely respectable noise figure.

This is completely unavoidable.

sreten.

[Timn8ter]

I hear noise from it even when the signal to a normal fully integrated amplifier is perfectly zero (short circuit).

which is how you test for noise, right?

[sreten]

Originally posted by Timn8ter

which is how you test for noise, right?

No of course it isn't, unless you want misleading
results, especially for moving magnet RIAA inputs.

sreten.

[Drew Eckhardt]

Originally posted by awboy


What the hell is this, and why should I put up with it?

Johnson noise aka thermal noise, because you can't eliminate it without dropping the temperature to absolute zero.

The following will make it more aparant:
1. Sensitive speakers
2. Circuits with higher resistances
3. Preamplifiers with gain.

[awboy]

Yes Drew, I do mean that I hear an almost white nois source, and not dc klicking or such (leadbelly).
Say that the source is (high) resistor Johnson noise, then buffering the input before the resistor (volume knob) should help, n'est ce pas?

Originally posted by Drew Eckhardt


Johnson noise aka thermal noise, because you can't eliminate it without dropping the temperature to absolute zero.

The following will make it more aparant:
1. Sensitive speakers
2. Circuits with higher resistances
3. Preamplifiers with gain.

[Drew Eckhardt]

Originally posted by awboy
Yes Drew, I do mean that I hear an almost white nois source, and not dc klicking or such (leadbelly).
Say that the source is (high) resistor Johnson noise, then buffering the input before the resistor (volume knob) should help, n'est ce pas?

You could probably buffer the input with an op-amp and then use a lower resistance (5K instead of 50K) attenuator.