Exotic Amplifier Technologies - Page 2

You're not getting much smarter, are you?

IF you have a problem with crossposting (or top posting, or whatever you
imagine is a problem), then take it up with the original poster.


**** As far as I'm concerned,YOU are the original poster!

Brian Goldsmith.

**Then you have a great deal to learn.

I am neither the original poster, nor a top poster. Go away and learn how to
use your newsreader, then come back to us.


I suggest you do some actual research, before making a complete fool of
yourself next time.

BTW: You have still not managed to answer my question. Be as technical as
you feel necessary. In your answer, you may care to examine the impedance
characteristics of headphones and relate what might happen to the frequency
response, when driven by different impedance sources.

Because your speakers were actually worth a darn?

Arny Krueger wrote in message ...



Arnie, I think you well know that speakers that could equal a HP like the
Sennheiser HD595 for sheer reality in every area would cost many thousands,
and I don't have many thousands. Also I don't wish to annoy the neighbours
nor other members of the household. Headphones are perfect for me.

I'm not sure that speakers can duplicate headphones, or vice-versa. So the
question of relative costs is rediculous.



I'm not debating the advantages of headphones. As you know Paul, I probably
have more headphones and earphones by accident then you have on purpose. But
I also have a few speakers...



That's fine, but Paul if you are sold on the exclusive use of headphones
(nothing wrong with that!) why did you ask the question you did?

Agreed. Speakers and headphones are a totally different listening
experience.



I only have one pair of headphones and one pair of speakers. But I've
listened to scores of phones over the years at length.



Refresh my memory.

I have about 5 pairs of pretty good speakers, some better than others. These
days I mostly listen to the  NHT 2.5is (main A/V system), the Boston
Acoustics CR-9s (TV set) and the aftermarket speakers in my van and car.

I have about 15 different pairs of headphones and earphones. I mostly listen
to the HD580s Iistening at home for pleasure) Sony MDR 7506 (editing)
Futuresonics IEM (portable digital player) and Shure E-3 (portable CD/MP3
player).

The 580s are a good phone, but I found them a little dull and boring.
The 595 has the same or greater neutrality, a better soundstage and is
more lively--also much easier to drive. I've not looked back since I
bought it, and unless they bring out a "super" 595 it will be my last
phone for many years.

There are a lot of people who think that for listening, they are exactly
right. If not, one can throw in a little eq - that is if you have some eq at
your disposal. Ever since we got the digital console at church, we've been
pulling eq out of service.



That would be your personal opinon, which is of course yours to cherish. As
far as the easier to drive thing goes, 580s have a nice combination of
sensitivity and high impedance, and have to be the easiest headphones to
drive of the over a dozen that I have. I've been known to drive them
straight off of the line output of some audio production component or other,
without difficulty. I do have a number of headphone amps, but with 580s
their use is optional.

Isn't it better if things don't need eq? After all, you're adding
another component with its own measure of distortion.



But not easier than the 580, which I owned. The 595 is much easier to
drive, and that's the old 120 ohm version. Senn have now switched to
50 ohms.

I'm assuming you're very familiar with the 595.

Of course it is. In case you haven't figured it out, the reason to use eq is
that it makes things sound better. If the eq doesn't make things sound
better, then the wise person either comesup with different eq or forgets
about eq altogether in this application.



The problem isn't usually the inherent distortion in modern equalizers
(which is very low) its errors in adjusting the eq.





The 580 is so easy to drive I can't see that as a criteria to judge it by.



You seem to have an odd idea of what constitutes easy to drive, Paul.
Usually high impedances are easier to drive than low impedances, all other
things being equal.



Marginally.

You're totally at odds with received wisdom here, Arnie. Check the
search engines on any headphone site (say, Head-Fi) and you'll find
the 580 is one of those phones considered to definitely need a
dedicated HP amp, the 595 not. And this accords with my own
experience. Where I would have had the volume at 10.30 with the 580, I
rarely have it beyond 9.15 with the 595. Or perhaps you have a
different way of measuring sensitivity?

Head Fi is a forum, IOW its the blind leading the blind.



Asa long as the phones are more than loud enough with the volume knob CCW of
clipping, why should anybody care?

Which they never are unfortunately.
In fact with portable equipment the maximum output voltage levels are quite
often too low to properly drive high impedance phones IME.
Not that I am unhappy at all with my Senn 580's. I have other phones more
suitable for portable use, and others still for live monitoring etc.

MrT.

Yes, there are some high impedance headphones that are tough to drive
because they need so much voltage.



Agreed. Too much of this stuff runs off of just 1.5 volts. 3 volts is
better, and 5 volts covers a lot of territory.



I use IEMs for portable use, and less costly stuff that I sacrifice at the
altar of live sound.

By pointing out the 400 watt capabilities of these amps, you supported my
claim. Thank you very much, Trevor.

**Of course. Such amps are rarely used in critical listening situations.
Power output, cost and size and the over-riding factors.

Trevor Wilson wrote:



The feedthrough from the rail switching into the audio path is actually minute.

I've designed several rail switching amps for SR use. As Arny says though, there
is considerable extra complexity in the bits so I wouldn't use the method much
below the 400-500 wpc category.

Graham

Pooh Bear wrote:

there


It makes sense even in smallish amps where heat disposal is an issue,
ie in pg 9 of :
http://www.st.com/stonline/products/literature/ds/6744.pdf
M

**Perhaps. That is not the major part of the problem. Examine the curves of
the output devices. Look at the difference in characteristics with different
VCE applied.



**You may not. All the companies I quoted did use them in lower powered
amps. NAD have used rail switchers in amps with continuous power outputs as
low as 30 Watts.