Higgs Boson wrote:
Bobby G. thanks for your civilized reply to previous poster. The
Internet seems to bring out the best in some people and the worst in others.

[...thread snipped....]

Might be time to wind up the thread with thanks to all for suggestions.
Some are beyond my capabilities. One of yours might be my best shot. You wrote:

"I might be equally tempted to buy a $25 headphone amplifier box with RCA
inputs and 1/4" stereo headphone outputs."

VERY IMPORTANT: Before proceeding, I need to know: Where is the
headphone amplifier getting its sound, if the stereo jack cannot be used?
Not from the POS TV speakers, one hopes!

I read several articles on-line on "how do headphone amplifiers work" but
did not find the above basic info. Any info/referencs appreciated.

HB

I've bought cheap integrated amps, like old radio shack units, which have a
headphone jack. Most amplifier units tap off the main speaker outs with
resistors to attenuate the level suitable for headphones. No power is taken
with input jacks, its just converted from a voltage source, to something
hat can supply required current. Want to check eBay ?

Some amplifier units have a separate headphone amplifier, but not as
common.

I got one one of the simplest headphone DIY circuits on the Internet. I
designed it as a , well why not ? There are many who took it steps further
for improvement, but that defeated my desire for simplicity. My project
started about 1985, now hundreds of users built it.

Greg

"gregz" wrote in message
...
Higgs Boson wrote:
Bobby G. thanks for your civilized reply to previous poster. The
Internet seems to bring out the best in some people and the worst in
others.

[...thread snipped....]

Might be time to wind up the thread with thanks to all for suggestions.
Some are beyond my capabilities. One of yours might be my best shot.
You wrote:

"I might be equally tempted to buy a $25 headphone amplifier box with
RCA
inputs and 1/4" stereo headphone outputs."

VERY IMPORTANT: Before proceeding, I need to know: Where is the
headphone amplifier getting its sound, if the stereo jack cannot be
used?
Not from the POS TV speakers, one hopes!

I read several articles on-line on "how do headphone amplifiers work"
but
did not find the above basic info. Any info/referencs appreciated.

HB

I've bought cheap integrated amps, like old radio shack units, which have
a
headphone jack. Most amplifier units tap off the main speaker outs with
resistors to attenuate the level suitable for headphones. No power is
taken
with input jacks, its just converted from a voltage source, to something
hat can supply required current. Want to check eBay ?

I've been trying to determine how her Harmon Kardon is connected to her TV.
I suspect it's by RCA phono patch cables, but it could be a speaker tap or
something else.

Some amplifier units have a separate headphone amplifier, but not as
common.

I think I have a dead HK upstairs I can check - no wait, it's a Sherwood.
My advice to HB is of course dependent on how she has the TV connected to
the HK. I assume it's line level audio out coming from jacks on the TV.
Most slim TV's I've seen acknowledge how crappy their built-in speakers and
provide one or more ways to "export" audio to a better reproduction device.

While most wireless headphones are equipped to "drop in" to a circuit made
with RCA patch cords, oddly, the only thing I have been able to find in the
wired department are four channel headphone amps. These take the signal via
RCA patch cables from a device's "AUDIO LINE OUT" jack and distribute it to
four separate headphone jacks with separate volume controls.

This one's $44 but a single channel unit should be out there for around $25.
Higgs can search and submit candidates for approval g as an exercise for
the student.

http://www.amazon.com/Rolls-HA43-Hea.../dp/B00102ZOQC

I got one one of the simplest headphone DIY circuits on the Internet. I
designed it as a , well why not ? There are many who took it steps further
for improvement, but that defeated my desire for simplicity. My project
started about 1985, now hundreds of users built it.

So where's the darn URL, Greg? g

If HB wants to learn, building a simple circuit is the way to go. If not,
maybe someone will voluteer to build it for her for cost.

I got my feet wet with the remarkable 555 chip, which wasn't very accurate
but certainly was very versatile (and CHEAP, too). First project was a
variable speed reversing relay control for my Uniroller film developer
complete with status LEDs (which sad to say were pretty new at the time) and
(completely superfluous) beeper.

As an aside, today I got an HDMI to composite device for $20 that solves the
problem of my new CCTV recorder having only VGA and HDMI outputs. Now I can
pump the CCTV output through the analog TVs throughout the house like the
old DVR did. I was pretty surprised when I went to connect the RCA "VIDEO
IN" cable of my home distribution network and there was no "VIDEO OUT" on
the new DVR as there was on the older one.

It was a reminder that like PC's, the connector that's been there for 20
years might disappear next year. g I didn't even think to check the specs
to see if the new unit had a composite video out. Now I get to find out if
the unit supports simultaneous video output to both HDMI and VGA. I have my
fingers crossed (but no M-M VGA cable so far to test with).

--
Bobby G.

"Robert Green" wrote:
"gregz" wrote in message
...
Higgs Boson wrote:
Bobby G. thanks for your civilized reply to previous poster. The
Internet seems to bring out the best in some people and the worst in
others.




I got one one of the simplest headphone DIY circuits on the Internet. I
designed it as a , well why not ? There are many who took it steps further
for improvement, but that defeated my desire for simplicity. My project
started about 1985, now hundreds of users built it.

So where's the darn URL, Greg? g


Some time ago a guy was setting up a headphone web page, by the name CMOY.
Was asking for designs for amps. He also has his version of an integrated
portable device. The site is Headwize or Headwise ? Lots of headphone
stuff. I sent many emails trying to get specifics on my amp. You can just
google szekeres amp.
It's simple, but I don't recommend it for beginners.

Greg szekeres


If HB wants to learn, building a simple circuit is the way to go. If not,
maybe someone will voluteer to build it for her for cost.

I got my feet wet with the remarkable 555 chip, which wasn't very accurate
but certainly was very versatile (and CHEAP, too). First project was a
variable speed reversing relay control for my Uniroller film developer
complete with status LEDs (which sad to say were pretty new at the time) and
(completely superfluous) beeper.

As an aside, today I got an HDMI to composite device for $20 that solves the
problem of my new CCTV recorder having only VGA and HDMI outputs. Now I can
pump the CCTV output through the analog TVs throughout the house like the
old DVR did. I was pretty surprised when I went to connect the RCA "VIDEO
IN" cable of my home distribution network and there was no "VIDEO OUT" on
the new DVR as there was on the older one.

It was a reminder that like PC's, the connector that's been there for 20
years might disappear next year. g I didn't even think to check the specs
to see if the new unit had a composite video out. Now I get to find out if
the unit supports simultaneous video output to both HDMI and VGA. I have my
fingers crossed (but no M-M VGA cable so far to test with).

--
Bobby G.