Jim Lesurf said...

32 ohm headphones are very common as are 16 ohm headphones.

Yes. IIRC I mention one of the phones I used were about 18 Ohms, but the
three others I tried all came in around 32-35 Ohms.

I used several pairs of Sennheiser 414's before they went out of
production. They had a nominal impedance of 2,000 ohms and could be
operated from speaker outputs without problems. My first pair came
fitted with DIN ls plugs.

Theoretical question, Jim. If you were to redesign your DAC
specifically for HD414's would the transformers still be necessary?


--
Ken O'Meara
http://www.btinternet.com/~unsteadyken/

In article ,
UnsteadyKen
wrote:
Jim Lesurf said...

32 ohm headphones are very common as are 16 ohm headphones.

Yes. IIRC I mention one of the phones I used were about 18 Ohms, but
the three others I tried all came in around 32-35 Ohms.

I used several pairs of Sennheiser 414's before they went out of
production. They had a nominal impedance of 2,000 ohms and could be
operated from speaker outputs without problems. My first pair came
fitted with DIN ls plugs.

I also used to use HD414s for many years. But my old ones have
disintegrated and AFAIK you can't now get them, or the replacement bits. I
liked the sound overall for general test use, but found them uncomfortable
if used continuously for a long time. The new EH350s I have seem more
comfy. I suspect that have more extended bass as well, but can't be sure as
I am relying on comparing with memory. :-)

Theoretical question, Jim. If you were to redesign your DAC
specifically for HD414's would the transformers still be necessary?

Not sure, but it seems plausible that they wouldn't. Certainly the AU-D3
happily drives 1k. So a pair of 414s with a 1k or 2k2 volume pot would be
likely to be fine, I guess. That said I can't recall the sensitivity, so a
transformer might be useful. I'd need 414s to decide, and mine are long
past use.

FWIW One of the things that made me think 'transformer' was thinking "If I
still had HD414s their high impedance would mean I wouldn't need
buffers...".

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Jim Lesurf said...

I also used to use HD414s for many years. But my old ones have
disintegrated and AFAIK you can't now get them, or the replacement bits. I
liked the sound overall for general test use, but found them uncomfortable
if used continuously for a long time.

Comfort was one of their great strengths IMHO. You could heat the
headband and bent it to fit and it would keep that shape, leading to
forgetting you were wearing them and ripping the connectors out when
standing up. That was their main weakness the fragile connector system.
They were also strangely attractive to dogs, I lost 2 pairs by
chewing:-)


The new EH350s I have seem more
comfy. I suspect that have more extended bass as well, but can't be sure as
I am relying on comparing with memory. :-)

The 414's could sound a bit anaemic when connected to the typical
headphone output on an amp, I always connected them to speaker outputs,
it really brought them to life, but never used them with a proper phone
amp.

These; http://goo.gl/Q1bs arrived at the weekend and remind me very
much of the 414's sound and comfort. I had a pair of HD480's for years,
but lately been using HD495's which seem to have a degree of bass bost
and I wasn't very happy with them, now with the 490's I'm in Headphone
Heaven again.


Theoretical question, Jim. If you were to redesign your DAC
specifically for HD414's would the transformers still be necessary?

Not sure, but it seems plausible that they wouldn't. Certainly the AU-D3
happily drives 1k. So a pair of 414s with a 1k or 2k2 volume pot would be
likely to be fine, I guess. That said I can't recall the sensitivity, so a
transformer might be useful. I'd need 414s to decide, and mine are long
past use.

94 dB per 1mw or 1.41v; according to the manual


FWIW One of the things that made me think 'transformer' was thinking "If I
still had HD414s their high impedance would mean I wouldn't need
buffers...".



--
Ken O'Meara
http://www.btinternet.com/~unsteadyken/

UnsteadyKen wrote:

[HD414]

Comfort was one of their great strengths IMHO. You could heat the
headband and bent it to fit and it would keep that shape, leading to
forgetting you were wearing them and ripping the connectors out when
standing up. That was their main weakness the fragile connector
system.

That was not a weakness and they still use it on the HD25. In case, no cases
known, a headphone cable broke, you just got another and you didn't get a
repair chore out of making that error.

The 414's could sound a bit anaemic when connected to the typical
headphone output on an amp, I always connected them to speaker
outputs, it really brought them to life, but never used them with a
proper phone amp.

They were designed for all round usability, including direct connection to a
household size power amplifier, with their high impedance and because of
that high impedance cherished also as an electronics troubleshooting
implement.


Kind regards

Peter Larsen

In article , Peter Larsen
wrote:
UnsteadyKen wrote:

[HD414]


They were designed for all round usability, including direct connection
to a household size power amplifier, with their high impedance and
because of that high impedance cherished also as an electronics
troubleshooting implement.

I'd second that. IIRC I first started using them because Armstrong had them
for the test bench people. They provided a convenient way for testers to
hear what units did without all having speakers and amps (e.g. when
checking some aspects of preamp or tuner boards).

FWIW I like the sound with some headphones. But I always end up finding
them uncomfortable. Never found a pair that sound good and don't end up
hurting my ears. The tiny cheap light ones are more comfortable, but
generally sound poor.

So in general I just prefer speakers, which I find give a more pleasing
'image' as well. But headphones can certainly be useful, and give a
different 'take' on the sound, etc.

FWIW One of the reasons I chose a 'headphone DAC' as a minimal project was
the thought that it might be ideal for those who had an interest in better
audio but could not afford fancy (expensive) kit of the kinds generally
reviewed and raved about in magazines. Using headphones can be a much
cheaper way to decent results than power amp and speakers. And you can play
loud without bothering others.

If someone knows of better (i.e. higher signal ability with lower LF
distortion, lower internal resistance, and maybe a ratio like 5:1 or 6:1)
signal transformer that is cheap and easily available to UK amateurs I'd be
interested in knowing and giving them a try. The NTE4s are quite limited,
but to me seem to 'just manage' to give decent results. But something more
capable might be worth knowing about.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Thu, 29 Jul 2010 09:46:40 +0100, Jim Lesurf wrote:

FWIW I like the sound with some headphones. But I always end up finding
them uncomfortable. Never found a pair that sound good and don't end up
hurting my ears. The tiny cheap light ones are more comfortable, but
generally sound poor.

I listen a lot with headphones and I have 3 Technics RP-F880 in use, two in my
apartment and because I did not want to carry them I got an extra pair at my parents.
Lately I find that when I'm visintg the old folks my headphones are at my mothers
desk, and not on mine in my old room. Hmmmmm. They are comfy and sound great, but I
got my mother a Siberia from the Steelseries at the local hifi shop. I never use the
mike though. Turns out my sister is using the Siberias at my parents. Why can't they
go shopping through 20 headphones and find one themselves, like I did?

I also use an AKG K240DF from 1978, from England in fact. Nice chap sold it on eBay
in the original box and he had kept the store brochure.

I have for a long time thought of expanding into more expensive headphones but I find
myself unwilling to part with the money they cost. I like the diversity of the 20 or
so I have aquired on budget terms (as in second hand). Philips, AKG, Sennheiser,
Stax, Sony, B&O, Denon. I had a nice set of Nokia tv headphones which I lent away,
and received with both drivers dead. Was just the cable. My Denon had both drivers
die, im my hands, but the Nokia drivers fit right in.

My worst experience was the lightweight Pooneers I bought about 20 years ago. I sat
down on them after just two weeks. Never put headphones on a chair. Take it from me.

I think it is great that new pads and such are available for Stax and B&O.

-Mikkel

In article ,
UnsteadyKen
wrote:
Jim Lesurf said...

I also used to use HD414s for many years. But my old ones have
disintegrated and AFAIK you can't now get them, or the replacement
bits. I liked the sound overall for general test use, but found them
uncomfortable if used continuously for a long time.

Comfort was one of their great strengths IMHO. You could heat the
headband and bent it to fit and it would keep that shape, leading to
forgetting you were wearing them and ripping the connectors out when
standing up.

I found they soon felt like a pair of circular objects whose edges were
cutting into my ears. Over time the foam compressed and this came though.
Probably made worse because I wear glasses. So I always found after 15-30
mins I wanted to take them off. The EH350 is better, but I still find them
uncomfortable after a while.

That was their main weakness the fragile connector system.
They were also strangely attractive to dogs, I lost 2 pairs by
chewing:-)

I found the pads were useless at softening contact on my ears. If I
weakened the pressure the bass was lost.

These; http://goo.gl/Q1bs arrived at the weekend and remind me very
much of the 414's sound and comfort. I had a pair of HD480's for years,
but lately been using HD495's which seem to have a degree of bass bost
and I wasn't very happy with them, now with the 490's I'm in Headphone
Heaven again.


Theoretical question, Jim. If you were to redesign your DAC
specifically for HD414's would the transformers still be necessary?

Not sure, but it seems plausible that they wouldn't. Certainly the
AU-D3 happily drives 1k. So a pair of 414s with a 1k or 2k2 volume pot
would be likely to be fine, I guess. That said I can't recall the
sensitivity, so a transformer might be useful. I'd need 414s to
decide, and mine are long past use.

94 dB per 1mw or 1.41v; according to the manual

Well the AU-D3 gives 1 Vrms for 0dBFS if powered by about 5 Vdc. So I guess
you'd get a maximum of less than 94dB. It would work without transformers I
think, but perhaps not much louder than the EH350 whose specs claim 115 dB
for 1 Volt, but are 35 Ohm. Hence I guess I'm getting around 90 dB via the
present transformers.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html