Did you go to the various websites and see the specifications for yourself?

Obviously not. I didn't make them up, only reprinted them.




"Arny Krueger" wrote in message
...
"SST" wrote in message
et
better sound out of cheap headphones?

who said that?

have you always been this confused?

Oh and I meant mW not Mv - I work too much =)

Noting "SST" that you never admitted that at least some of the numbers
you
quoted for various devices are sheerest science fiction.

Here's two supposedly authoritation numbers from SST:

"Apple iPod (all models): Maximum Output = 60 mW"

"Nomad Jukebox 3: Maximum Output = 900 mW"

I don't have an iPod, but here's someone who does:

http://members.brabant.chello.nl/~m....surements.html

He says he tested with an 80% amplitude signal, which is about 2 dB below
full scale. IOW you can add 25% to his voltages to find the output of an
iPod with a full scale ( 0 dB) signal. (Voltages are millivolts)

Freq [Hz] 1 3 10 30 100 300 1000
10000
Output Voltage @ 1MOhm 65 88 90 90 90 90 90 90
Output Voltage @ 33Ohm 2 7 22 51 75 80 80 80

This corresponds to a 90 millivolt output with an approximate source
impedance at most frequencies of about 3 ohms.

There's no way that one can get 60 milliwatts out of an iPod! In fact the
maximum power that one can get out of an iPod can be calculated, and it
would be about 3 milliwatts.

As I pointed out before, I've measured the output of a NJB3, and find it
to
be about a volt with a full scale audio signal. Again no way can that be
900
milliwatts.

Finally, for the benefit people who find that the headphone jack of their
portable equipment lacks "oomph", I investigated the Radio Shack part
number
330-1109 3-Way Headphone Volume Booster. This device runs off of 2 AA
cells
and provides 3 headphone jacks. I ran some measurements on it and find
that
it has approximately 6 dB gain, 0.003% THD @ 1 KHz full output,
approximately 90 dB SNR and frequency response 20-20 KHz +0, - 0.3 dB. It
sells for the princely sum of $22.95. Here is its instruction manual
http://support.tandy.com/support_audio/doc65/65451.pdf .

The RS 330-1109 3-Way Headphone Volume Booster's maximum output is around
1
volt, much the same as the NJB3. Therefore when used with a NJB3, it
provides gain, but does not extend the NJB3's actual output voltage
capability. A NJB3 can overdrive it and produce nasty clipped sounds.
People
who want more loudness might want to investigate how it works with a
larger
power supply voltage.

Based on the information I've found about the iPod, there's no way it
could
overdrive the RS 330-1109 3-Way Headphone Volume Booster. Therefore it is
unquestionably a useful tool for iPod owners who are seeking both more
gain
and also more loudness.