I recently started using an old set of Kenwood HS-5 phones (8 ohm) after
my cat chewed through the cord on my nice hi-fi phones. I noticed that
the audio was much louder, I presume a result of the lower impedance.
I'm even thinking about adding some resistance in series, because the
audio gain is never past 9 o'clock, even with CONFIG AFG set to LOW.
The Kenwood phones also seem to have a much narrower frequency response
than 'good' ones. Personally I like this.
73,
Vic, 4X6GP/K2VCO
Rehovot, Israel
http://www.qsl.net/k2vco/
On 28 Dec 2015 22:36, W2RU - Bud Hippisley wrote:
Perhaps this will help:
Look up the specs on a good home audio amplifier — say, QSC or Crown.
You’ll find something called “damping factor”, and it’s often 50 or
more. Roughly speaking, it’s the ratio of the (loudspeaker) load
impedance to the internal (source) impedance of the audio amplifier.
So modern semi-pro and stereophile audio amplifiers are “grossly out
of specs”, as you put it.
I have a legacy, hernia-inducing McIntosh power amplifier,
circa-1960s, with output transformers and three taps — for 4-, 8-,
and 16-ohm loudspeaker loads. Nothing I’ve owned since then uses
output transformers or matched loads. Most audio amplifier designs
these days are voltage followers. Most manufacturers don’t attempt
to match source impedance to load impedance. Highly damped output
stages are “good” things to have.
Yes, it’s true that voltage-follower amplifiers deliver more power to
low-impedance loads than to high-impedance loads. But if I were to
follow your line of reasoning to its logical conclusion in the home
audio arena, I would conclude that 4-ohm speaker systems are
sonically superior to 16-ohm speaker systems simply because they
require more output power from the audio amplifier to play my music
collection.
Does that seem like a reasonable way to choose your stereo system
loudspeakers? Or headphones for your K3?
If your 100-ohm (or higher) headphones can’t provide reasonable
levels of undistorted sound pressure at your ears when your K3 or K3S
audio gain control is at, say, 9 or 10 o’clock, perhaps it’s time to
buy a new pair of “cans”. That’s certainly gotta be cheaper than
reverting to a 75A-4 with its audio output transformer and 500-ohm
tap.
Bud, W2RU
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