Re: Hi-impedance headphone design

[Watson A.Name - Watt Sun]

In article >,
mentioned...
> "Paul Burridge" > wrote...
> > What differentiates the internals of hi-z headphones from those of say
> > the 8 ohm type. I mean, how is all that extra impedance achieved?
>
> I see that you're crossposting to a ham group, which adds a twist to the
> discussion, because at least 25 years ago when I last paid attention to ham
> radio, the kind of headphones used in ham sets were different than the kind
> used these days for listening to music. Hams used 8 ohm dynamic phones, or
> they used hi-Z crystal phones.

I disagree. They used 2000 ohm variable reluctance headphones.

http://www.audiosears.com/acoustic/2444.html
http://www.audiosears.com/acoustic/ears.html



> The phones used for music listening these days are generally in the range of
> 30 to 100 ohms, with some oddballs around 600 ohms. They are dynamic, that
> is, they use electromagnets rather than piezo crystals. I don't know how
> they pack that much wire into 'em (although some do have two diaphragms in
> series, for each ear), but I think the basic idea is that where a
> loudspeaker has a heavy magnet and relatively few turns of wire, headphones
> work the other way - light (and weak) magnet, lots of turns.


--
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Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@

[Watson A.Name - Watt Sun]

In article >,
mentioned...
> "Paul Burridge" > wrote...
> > What differentiates the internals of hi-z headphones from those of say
> > the 8 ohm type. I mean, how is all that extra impedance achieved?
>
> I see that you're crossposting to a ham group, which adds a twist to the
> discussion, because at least 25 years ago when I last paid attention to ham
> radio, the kind of headphones used in ham sets were different than the kind
> used these days for listening to music. Hams used 8 ohm dynamic phones, or
> they used hi-Z crystal phones.

I disagree. They used 2000 ohm variable reluctance headphones.

http://www.audiosears.com/acoustic/2444.html
http://www.audiosears.com/acoustic/ears.html



> The phones used for music listening these days are generally in the range of
> 30 to 100 ohms, with some oddballs around 600 ohms. They are dynamic, that
> is, they use electromagnets rather than piezo crystals. I don't know how
> they pack that much wire into 'em (although some do have two diaphragms in
> series, for each ear), but I think the basic idea is that where a
> loudspeaker has a heavy magnet and relatively few turns of wire, headphones
> work the other way - light (and weak) magnet, lots of turns.


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@

[Bob Lewis \(AA4PB\)]

> Hams used 8 ohm dynamic phones, or they used hi-Z crystal phones.
>
> I disagree. They used 2000 ohm variable reluctance headphones.
>

Hams have always used anything available. 25 years ago was 1977. By
that time the vast majority of receivers were designed for 8-ohm
headphones as most are today. Hi-Z crystal phones haven't been in
general use for a long time.

[Bob Lewis \(AA4PB\)]

> Hams used 8 ohm dynamic phones, or they used hi-Z crystal phones.
>
> I disagree. They used 2000 ohm variable reluctance headphones.
>

Hams have always used anything available. 25 years ago was 1977. By
that time the vast majority of receivers were designed for 8-ohm
headphones as most are today. Hi-Z crystal phones haven't been in
general use for a long time.

[Capoot]

The high impedance phone that came with the crystal radio that I had when I
was a kid in the 50's had a large stationary coil wound around an iron core.
The sound was produced in a steel disc suspended over the iron core.
Because the coil was stationary and its mass did not have to move, it could
achieve the hi-z by adding many turns. Phones of 2K or higher can be
driven directly from the plate of a vacuum tube circuit. Is that the
context of your question? You could use a modern lo-z phone in such a
circuit with a matching plate-to-voicecoil type transformer.
Ray

"Watson A.Name - Watt Sun" > wrote in message
m...
> In article >,
> mentioned...
> > "Paul Burridge" > wrote...
> > > What differentiates the internals of hi-z headphones from those of say
> > > the 8 ohm type. I mean, how is all that extra impedance achieved?
> >
> > I see that you're crossposting to a ham group, which adds a twist to the
> > discussion, because at least 25 years ago when I last paid attention to
ham
> > radio, the kind of headphones used in ham sets were different than the
kind
> > used these days for listening to music. Hams used 8 ohm dynamic phones,
or
> > they used hi-Z crystal phones.
>
> I disagree. They used 2000 ohm variable reluctance headphones.
>
> http://www.audiosears.com/acoustic/2444.html
> http://www.audiosears.com/acoustic/ears.html
>
>
>
> > The phones used for music listening these days are generally in the
range of
> > 30 to 100 ohms, with some oddballs around 600 ohms. They are dynamic,
that
> > is, they use electromagnets rather than piezo crystals. I don't know
how
> > they pack that much wire into 'em (although some do have two diaphragms
in
> > series, for each ear), but I think the basic idea is that where a
> > loudspeaker has a heavy magnet and relatively few turns of wire,
headphones
> > work the other way - light (and weak) magnet, lots of turns.
>
>
> --
> @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@
> ###Got a Question about ELECTRONICS? Check HERE First:###
> http://users.pandora.be/educypedia/electronics/databank.htm
> My email address is whitelisted. *All* email sent to it
> goes directly to the trash unless you add NOSPAM in the
> Subject: line with other stuff. alondra101 <at> hotmail.com
> Don't be ripped off by the big book dealers. Go to the URL
> that will give you a choice and save you money(up to half).
> http://www.everybookstore.com You'll be glad you did!
> Just when you thought you had all this figured out, the gov't
> changed it: http://physics.nist.gov/cuu/Units/binary.html
> @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@

[Capoot]

The high impedance phone that came with the crystal radio that I had when I
was a kid in the 50's had a large stationary coil wound around an iron core.
The sound was produced in a steel disc suspended over the iron core.
Because the coil was stationary and its mass did not have to move, it could
achieve the hi-z by adding many turns. Phones of 2K or higher can be
driven directly from the plate of a vacuum tube circuit. Is that the
context of your question? You could use a modern lo-z phone in such a
circuit with a matching plate-to-voicecoil type transformer.
Ray

"Watson A.Name - Watt Sun" > wrote in message
m...
> In article >,
> mentioned...
> > "Paul Burridge" > wrote...
> > > What differentiates the internals of hi-z headphones from those of say
> > > the 8 ohm type. I mean, how is all that extra impedance achieved?
> >
> > I see that you're crossposting to a ham group, which adds a twist to the
> > discussion, because at least 25 years ago when I last paid attention to
ham
> > radio, the kind of headphones used in ham sets were different than the
kind
> > used these days for listening to music. Hams used 8 ohm dynamic phones,
or
> > they used hi-Z crystal phones.
>
> I disagree. They used 2000 ohm variable reluctance headphones.
>
> http://www.audiosears.com/acoustic/2444.html
> http://www.audiosears.com/acoustic/ears.html
>
>
>
> > The phones used for music listening these days are generally in the
range of
> > 30 to 100 ohms, with some oddballs around 600 ohms. They are dynamic,
that
> > is, they use electromagnets rather than piezo crystals. I don't know
how
> > they pack that much wire into 'em (although some do have two diaphragms
in
> > series, for each ear), but I think the basic idea is that where a
> > loudspeaker has a heavy magnet and relatively few turns of wire,
headphones
> > work the other way - light (and weak) magnet, lots of turns.
>
>
> --
> @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@
> ###Got a Question about ELECTRONICS? Check HERE First:###
> http://users.pandora.be/educypedia/electronics/databank.htm
> My email address is whitelisted. *All* email sent to it
> goes directly to the trash unless you add NOSPAM in the
> Subject: line with other stuff. alondra101 <at> hotmail.com
> Don't be ripped off by the big book dealers. Go to the URL
> that will give you a choice and save you money(up to half).
> http://www.everybookstore.com You'll be glad you did!
> Just when you thought you had all this figured out, the gov't
> changed it: http://physics.nist.gov/cuu/Units/binary.html
> @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@