Does anyone have direct experience with dedicated headphone amplifiers,
which are reputed to drive cans like the Sennheiser HD600's the way nature
intended..and give far better results than the typical op amp fed headphone
circuit in mixers, cd players, etc ? An example of the species I'm referring
to would be the Musical Fidelity X-Cans.
Any (on topic) input appreciated.......
Thanks,
Ray


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"Ray Thomas" wrote in message

Does anyone have direct experience with dedicated headphone
amplifiers, which are reputed to drive cans like the Sennheiser
HD600's the way nature intended..and give far better results than the
typical op amp fed headphone circuit in mixers, cd players, etc ? An
example of the species I'm referring to would be the Musical Fidelity
X-Cans. Any (on topic) input appreciated.......

Since you mentioned "the way nature intended", I must question why there
would be anything wrong with the use of appropriate op amps for headphone
amplifiers. After all, the active components in the audio paths of mixers,
CD players, and etc. are almost always op amps.

Since you mentioned the Sennheiser HD-600s, you should know that these are
among the easiest of all headphones to drive in a audio production
environment, due to their high impedance (300-600 ohms). They have almost
enough additional power sensitivity, so that it does not a great deal more
voltage to drive them than most far lower-impedance (16-32 ohms) headphones
such as the Sony MDR 7506s.

This family of Sennheiser headphones (HD580-650) can be useful for
attachment directly to some of the more robust line outputs around, without
the use of any headphone amplifier at all. Their impedance is high enough
and flat enough that being driven by say 75 ohm impedance sources only adds
a few dB of response variation which pales in comparison to their natural
frequency response variations. This contrasts with their reputation for use
with portable audio gear, where they are a bit shy of sensitivity when
driven by audio gear that is straining to put out even 1 volt RMS. Most
audio production gear is capable of 2 to 6 volts RMS, in comparison.

The headphone amps that seem technically interesting are those that include
response tailoring and cross-feed circuits to make the psychoacoustic
experience of listening to headphones more similar to that of listening to
speakers.

The major difference between headphone listening and speaker listening is
the effect of Head-Related Transfer Functions, which are well known to exist
and be of a magnitude that is clearly audible.

As a practical matter, many listeners seem to learn how to mentally
translate their headphone listening experiences so that they can perform
more like they are listening to speakers.

"Ray Thomas" wrote in message

Does anyone have direct experience with dedicated headphone
amplifiers, which are reputed to drive cans like the Sennheiser
HD600's the way nature intended..and give far better results than the
typical op amp fed headphone circuit in mixers, cd players, etc ? An
example of the species I'm referring to would be the Musical Fidelity
X-Cans. Any (on topic) input appreciated.......

Since you mentioned "the way nature intended", I must question why there
would be anything wrong with the use of appropriate op amps for headphone
amplifiers. After all, the active components in the audio paths of mixers,
CD players, and etc. are almost always op amps.

Since you mentioned the Sennheiser HD-600s, you should know that these are
among the easiest of all headphones to drive in a audio production
environment, due to their high impedance (300-600 ohms). They have almost
enough additional power sensitivity, so that it does not a great deal more
voltage to drive them than most far lower-impedance (16-32 ohms) headphones
such as the Sony MDR 7506s.

This family of Sennheiser headphones (HD580-650) can be useful for
attachment directly to some of the more robust line outputs around, without
the use of any headphone amplifier at all. Their impedance is high enough
and flat enough that being driven by say 75 ohm impedance sources only adds
a few dB of response variation which pales in comparison to their natural
frequency response variations. This contrasts with their reputation for use
with portable audio gear, where they are a bit shy of sensitivity when
driven by audio gear that is straining to put out even 1 volt RMS. Most
audio production gear is capable of 2 to 6 volts RMS, in comparison.

The headphone amps that seem technically interesting are those that include
response tailoring and cross-feed circuits to make the psychoacoustic
experience of listening to headphones more similar to that of listening to
speakers.

The major difference between headphone listening and speaker listening is
the effect of Head-Related Transfer Functions, which are well known to exist
and be of a magnitude that is clearly audible.

As a practical matter, many listeners seem to learn how to mentally
translate their headphone listening experiences so that they can perform
more like they are listening to speakers.

"Ray Thomas" wrote in message
...
Does anyone have direct experience with dedicated headphone amplifiers,
which are reputed to drive cans like the Sennheiser HD600's the way nature
intended..and give far better results than the typical op amp fed
headphone
circuit in mixers, cd players, etc ? An example of the species I'm
referring
to would be the Musical Fidelity X-Cans.

Are HD600s les than 100 Ohms ? If not, what's the problem with 'normal'
headhone amps ?


geoff

"Ray Thomas" wrote in message
...
Does anyone have direct experience with dedicated headphone amplifiers,
which are reputed to drive cans like the Sennheiser HD600's the way nature
intended..and give far better results than the typical op amp fed
headphone
circuit in mixers, cd players, etc ? An example of the species I'm
referring
to would be the Musical Fidelity X-Cans.

Are HD600s les than 100 Ohms ? If not, what's the problem with 'normal'
headhone amps ?


geoff

In article ,
Ray Thomas wrote:
Does anyone have direct experience with dedicated headphone amplifiers,
which are reputed to drive cans like the Sennheiser HD600's the way nature
intended..and give far better results than the typical op amp fed headphone
circuit in mixers, cd players, etc ? An example of the species I'm referring
to would be the Musical Fidelity X-Cans.

Sure. They are a good idea. Krell used to make a really wonderful one, and
I think Bryston still does. I did one as a DIY project in Vacuum Tube Valley
magazine a few years back.

If you have to drive a whole lot of cans, using a regular power amp
designed for speakers into a distribution panel is probably a good idea,
and cheaper than most dedicated headphone amps.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

In article ,
Ray Thomas wrote:
Does anyone have direct experience with dedicated headphone amplifiers,
which are reputed to drive cans like the Sennheiser HD600's the way nature
intended..and give far better results than the typical op amp fed headphone
circuit in mixers, cd players, etc ? An example of the species I'm referring
to would be the Musical Fidelity X-Cans.

Sure. They are a good idea. Krell used to make a really wonderful one, and
I think Bryston still does. I did one as a DIY project in Vacuum Tube Valley
magazine a few years back.

If you have to drive a whole lot of cans, using a regular power amp
designed for speakers into a distribution panel is probably a good idea,
and cheaper than most dedicated headphone amps.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Arny Krueger wrote:

Since you mentioned "the way nature intended", I must question why there
would be anything wrong with the use of appropriate op amps for headphone
amplifiers. After all, the active components in the audio paths of mixers,
CD players, and etc. are almost always op amps.

Because you cannot get high voltage monolithics any more, not at any decent
price. The OPA604 will run on +/-24V rails, and TI and Apex make some
nasty-sounding higher voltage ones, but there are just no decent high voltage
monolithic parts at all. You cannot drive 600 ohm headphones with a 48V
voltage source without clipping.

There is a cute discrete op-amp based power amplifier that Opamp Labs sells.
It's somewhat 1975ish, but it's better than you'd expect given that.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Arny Krueger wrote:

Since you mentioned "the way nature intended", I must question why there
would be anything wrong with the use of appropriate op amps for headphone
amplifiers. After all, the active components in the audio paths of mixers,
CD players, and etc. are almost always op amps.

Because you cannot get high voltage monolithics any more, not at any decent
price. The OPA604 will run on +/-24V rails, and TI and Apex make some
nasty-sounding higher voltage ones, but there are just no decent high voltage
monolithic parts at all. You cannot drive 600 ohm headphones with a 48V
voltage source without clipping.

There is a cute discrete op-amp based power amplifier that Opamp Labs sells.
It's somewhat 1975ish, but it's better than you'd expect given that.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Assuming, after reading the other posts, you still want or need an amp, I
found an outstanding one from the German outfit, Pro-ject, available from
Music Direct, an audiophile retailer in Chicago (www.amusicdirect.com/). I
think it cost $250. I use it with Sennheiser 600s.

"Uncle Russ" Reinberg

WESTLAKE PUBLISHING COMPANY
www.finescalerr.com
WESTLAKE RECORDS
www.westlakerecords.com


"Ray Thomas" wrote in message
...
Does anyone have direct experience with dedicated headphone amplifiers,
which are reputed to drive cans like the Sennheiser HD600's the way nature
intended..and give far better results than the typical op amp fed
headphone
circuit in mixers, cd players, etc ? An example of the species I'm
referring
to would be the Musical Fidelity X-Cans.
Any (on topic) input appreciated.......
Thanks,
Ray


---
Outgoing mail is certified Virus Free.
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Assuming, after reading the other posts, you still want or need an amp, I
found an outstanding one from the German outfit, Pro-ject, available from
Music Direct, an audiophile retailer in Chicago (www.amusicdirect.com/). I
think it cost $250. I use it with Sennheiser 600s.

"Uncle Russ" Reinberg

WESTLAKE PUBLISHING COMPANY
www.finescalerr.com
WESTLAKE RECORDS
www.westlakerecords.com


"Ray Thomas" wrote in message
...
Does anyone have direct experience with dedicated headphone amplifiers,
which are reputed to drive cans like the Sennheiser HD600's the way nature
intended..and give far better results than the typical op amp fed
headphone
circuit in mixers, cd players, etc ? An example of the species I'm
referring
to would be the Musical Fidelity X-Cans.
Any (on topic) input appreciated.......
Thanks,
Ray


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.799 / Virus Database: 543 - Release Date: 19/11/2004

(Scott Dorsey) wrote in
:

You cannot drive 600 ohm
headphones with a 48V voltage source without clipping.

What exactly do you mean here?

You can generate 48 VRMS clean at the output, but the minute you connect
the load, it clips?

It can't generate 48V clean?

(Scott Dorsey) wrote in
:

You cannot drive 600 ohm
headphones with a 48V voltage source without clipping.

What exactly do you mean here?

You can generate 48 VRMS clean at the output, but the minute you connect
the load, it clips?

It can't generate 48V clean?

Drily Lit Raga wrote:
(Scott Dorsey) wrote in
:

You cannot drive 600 ohm
headphones with a 48V voltage source without clipping.

What exactly do you mean here?

You can generate 48 VRMS clean at the output, but the minute you connect
the load, it clips?

I mean 48VRMS isn't anywhere enough voltage to get high output level from
those phones. You need to be able to drive more voltage into the load.

It can't generate 48V clean?

That's the problem with LOW impedance phones. Now, you put a pair of 15 ohm
phones on one of those outputs, then the level starts to sag and the current
drive ability becomes the issue.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Drily Lit Raga wrote:
(Scott Dorsey) wrote in
:

You cannot drive 600 ohm
headphones with a 48V voltage source without clipping.

What exactly do you mean here?

You can generate 48 VRMS clean at the output, but the minute you connect
the load, it clips?

I mean 48VRMS isn't anywhere enough voltage to get high output level from
those phones. You need to be able to drive more voltage into the load.

It can't generate 48V clean?

That's the problem with LOW impedance phones. Now, you put a pair of 15 ohm
phones on one of those outputs, then the level starts to sag and the current
drive ability becomes the issue.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:

Arny Krueger wrote:

Since you mentioned "the way nature intended", I must question why there
would be anything wrong with the use of appropriate op amps for headphone
amplifiers. After all, the active components in the audio paths of mixers,
CD players, and etc. are almost always op amps.

Because you cannot get high voltage monolithics any more, not at any decent
price. The OPA604 will run on +/-24V rails, and TI and Apex make some
nasty-sounding higher voltage ones, but there are just no decent high voltage
monolithic parts at all. You cannot drive 600 ohm headphones with a 48V
voltage source without clipping.

There is a cute discrete op-amp based power amplifier that Opamp Labs sells.
It's somewhat 1975ish, but it's better than you'd expect given that.

TI specs the 5532 at +/- 22V max rating btw. I think that the 22V parts used to
be only industrial/military grade and commercial were +/- 18V max but I may be
mistaken.

http://focus.ti.com/lit/ds/symlink/ne5532a.pdf

Graham

Because you cannot get high voltage monolithics any more, not at any
decent
price. The OPA604 will run on +/-24V rails, and TI and Apex make some
nasty-sounding higher voltage ones, but there are just no decent high
voltage
monolithic parts at all. You cannot drive 600 ohm headphones with a 48V
voltage source without clipping.


I've built four headphone amps with very high gain & four output current
buffers in parallel. In two of them I used a +/- 18V split supply & it
drives my 600 Ohm AKG and Senheiser headphones to extremely high levels with
no clipping. From what I've actually measured on the bench, I'd observe that
as long as you have enough current capacity & aren't going into current
limiting at high gain settings, then you won't clip into 600Ohm phones at
usable levels with a 36V supply.

Skler

"Scott Dorsey" wrote in message

Arny Krueger wrote:

Since you mentioned "the way nature intended", I must question why
there would be anything wrong with the use of appropriate op amps
for headphone amplifiers. After all, the active components in the
audio paths of mixers, CD players, and etc. are almost always op
amps.

Because you cannot get high voltage monolithic any more, not at any
decent price.

The OP's post did not seem to restrict discussion to just monolithic op
amps. Discrete op amps are still pretty common in higher powered
applications. Almost every discrete SS audio power amp takes the form of an
op amp.

The OPA604 will run on +/-24V rails, and TI and Apex
make some nasty-sounding higher voltage ones, but there are just no
decent high voltage monolithic parts at all.

Agreed, however the OP we are discussing seems to want to eliminate the use
of op amps as components of equipment that would add addtional parts in
order to reach higher voltages.

You cannot drive 600
ohm headphones with a 48V voltage source without clipping.

Of course, everything with a voltage limit can be abused to the point of
clipping. However, are there really headphones that require what, 18 volts
rms to achieve reasonble volume levels?

"Pooh Bear" wrote in message



TI specs the 5532 at +/- 22V max rating btw. I think that the 22V
parts used to be only industrial/military grade and commercial were
+/- 18V max but I may be mistaken.

http://focus.ti.com/lit/ds/symlink/ne5532a.pdf

I've used 5532s and 5534s with highly-regulated power sources at just under
22 volts. IME over a period of time (years) the op amps measurably degrade.
They lose gain and start producing moderate amounts of distortion. A
semiconductor manufactuerer tech rep pointed out a known failure mode that
seemed related to this, but I've forgotten the details. Bottom line, 18
volts is a better choice.

On Tue, 23 Nov 2004 11:27:11 +0100, Ray Thomas wrote
(in article ):

Does anyone have direct experience with dedicated headphone amplifiers,
which are reputed to drive cans like the Sennheiser HD600's the way nature
intended..and give far better results than the typical op amp fed headphone
circuit in mixers, cd players, etc.?
---------------------------snip---------------------------

Yeah, the coolest-sounding (and heaviest-duty) headphone amps I've ever seen
are the ones made by these guys:

HeadRoom
2020 Gilkerson Drive
Bozeman, MT 59715
(800) 828-8184
http://www.headphone.com/

Their headphone amps range in price from about $100 to well over $5000, with
a couple of dozen different models.

Coincidentally, I just bought a pair of Etymotic earphones from them, and
they have great prices and fast shipping. Very nice people.

--MFW

"Arny Krueger" wrote in message
...
"Pooh Bear" wrote in message



TI specs the 5532 at +/- 22V max rating btw. I think that the 22V
parts used to be only industrial/military grade and commercial were
+/- 18V max but I may be mistaken.

http://focus.ti.com/lit/ds/symlink/ne5532a.pdf

I've used 5532s and 5534s with highly-regulated power sources at just
under
22 volts. IME over a period of time (years) the op amps measurably
degrade.
They lose gain and start producing moderate amounts of distortion. A
semiconductor manufactuerer tech rep pointed out a known failure mode that
seemed related to this, but I've forgotten the details. Bottom line, 18
volts is a better choice.

Hmm. I do the same thing -- highly reguled 21V supplies. And I've found no
degradation at all. They still measure very well.

Were your chips Signetics or TI?

Peace,
Paul

"Paul Stamler" wrote in message

"Arny Krueger" wrote in message
...
"Pooh Bear" wrote in message



TI specs the 5532 at +/- 22V max rating btw. I think that the 22V
parts used to be only industrial/military grade and commercial were
+/- 18V max but I may be mistaken.

http://focus.ti.com/lit/ds/symlink/ne5532a.pdf

I've used 5532s and 5534s with highly-regulated power sources at
just under 22 volts. IME over a period of time (years) the op amps
measurably degrade. They lose gain and start producing moderate
amounts of distortion. A semiconductor manufactuerer tech rep
pointed out a known failure mode that seemed related to this, but
I've forgotten the details. Bottom line, 18 volts is a better choice.

Hmm. I do the same thing -- highly reguled 21V supplies. And I've
found no degradation at all. They still measure very well.

I admit it, I pushed the margins closer - 21.9 or so volts. The circuit was
a test oscillator that was steadily putting out 10 v rms, and the load was
low Z - generally under 1K.

Were your chips Signetics or TI?

Signetics.

"Arny Krueger" wrote in message
...
You cannot drive 600
ohm headphones with a 48V voltage source without clipping.

Of course, everything with a voltage limit can be abused to the point of
clipping. However, are there really headphones that require what, 18 volts
rms to achieve reasonble volume levels?

Probably more like 15V RMS, but still over 1/3W @ 600 ohms. That's pretty
inefficient headphones! Even AKG's get by with less than that.
Passive near field monitors maybe :-)

TonyP.

"TonyP" wrote in message

"Arny Krueger" wrote in message
...
You cannot drive 600
ohm headphones with a 48V voltage source without clipping.

Of course, everything with a voltage limit can be abused to the
point of clipping. However, are there really headphones that require
what, 18 volts rms to achieve reasonble volume levels?

Probably more like 15V RMS, but still over 1/3W @ 600 ohms. That's
pretty inefficient headphones! Even AKG's get by with less than that.
Passive near field monitors maybe :-

Here's a wild idea:

Drive the common side of the headphone jack with -0.5*(L+R).

Drive the L terminal with L-0.5*R

Drive the R terminal with R-0.5*L

The L headphone element gets 1.5*L while playing the left channel source.

The R headphone element gets 1.5*R while playing the right channel source.

Op amps that can run on +/-24 volts develop headphone output comparable to
op amps running on +/- 36. Seems like 15-20 VRMS or more is a slam dunk!

Yeah, things can get a little strange if you play mono...