In article , David Looser
wrote:
"Jim Lesurf" wrote


And as I've pointed out there is no reason in principle why that can't
work fine.

In theory it can work fine, but a high-performance analogue filter for a
non-oversampling converter is neither simple nor cheap.

Indeed. Hence the earlier points I made.

The devil is then in the details when it comes to assessing one
implimentation versus others and the nominal spec for CDDA. I can
think of potential advantages and snags of either approach.

And your potential advantages for the non-oversampling approach are?

As ever, that depends entirely on the implimentations being compared and
the purpose/use/etc. However there is one example so obvious that I'm
puzzled that you don't seem to have realised.

If you don't employ oversampling or resampling then you don't risk problems
with some intersample peaks being above 0dBFS. Oversampling and resampling
systems need to allow for values as much as 3 or 4 dB above any individal
values in the source stream to avoid overflows. Using a non-oversampling
DAC followed by analogue filters with enough headroom means the digital
system doesn't need this extra 'bit' or so above 0dBFS.

Of course, correctly implimented oversampling systems will allow for the
needed headroom. Just as correctly implimented non-oversampling ones with
use appropriate analogue filtering. So the exchange is that oversampling
reduces HF spurons at the risk of intersample problems, whereas
non-oversamplng reduces intersample problems at the risk of HF ones. Yer
pays yer money and yer takes yer choice. Ideally getting something you are
happy with either way.


I've been happy enough with oversampling DACs like the Meridian (and
now the DACMagic) for some years. Still enjoy the results they give.

Are they multi-bit oversampling designs, or, like the majority of audio
DACs these days, of the 1-bit variety?

Afraid I can't recall if the 263 and 563 I use are 'one bit' or 'low bit'.
Either way they are moderate order delta-sigma oversampling as I recall.
The DAC magic I think just resamples to a higher rate whilst keeping a fair
bit depth per sample. Does this by applying a TDA type method I think to
get the 'intersamples' with the chosen filter properties.

Pure '1 bit' needs to be used with caution, as does high order delta-sigma.
Too easy to get into chaotic trails or problems with levels that approach
near max. IIRC That was (is?) a basic snag with DSD/SACD. I think Philips
simply arranged for DSD streams to avoid going above the central range to
minimise that cropping up in use. But given what producers do with heavily
clipped CDs I wonder if any SACDs have problems. Can't say as I only have a
few (hybrid) SACDs and just listen to their CD layer. Although comparing
the layers is one of the many items on my "must get around to that" list.
:-)

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
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Audio Misc http://www.audiomisc.co.uk/index.html

"Fed Up Lurker" wrote

You Dave won't get the gist of this one

On the contrary I get the "gist" of it only too well!

the essense of how it works and why is sounds as it does is simply
bypassing the filter.

Just that?, you don't replace the bypassed digital filter with an analogue
one?

So Dave, because you never heard of it dosen't mean it never existed.

Heard of what? If you mean non-oversampled audio DACs I heard of them about
40 years ago!

Arny is going to give it a try, and obviously Jim is beguiled by the whole
concept. Unfortunately this group is too narrow so any more info will
be on a need-to-know basis.

Ah yes! your preference for dropping hints about things rather than saying
what you mean. I'd noticed that you like to do that :-). Makes you feel
superior does it?

David.

In article , Fed Up Lurker
wrote:
[snip]

So Dave, because you never heard of it dosen't mean it never existed.
Arny is going to give it a try, and obviously Jim is beguiled by the
whole concept.

I am interested and do plan to do some closer examination and comparisons
sometime. But do have loads of other things on the same 'to do' list. :-)

I don't think Jim is talking to me anymore, I think he finds me too
annoying and maybe strings have been pulled?

You do seem to keep repeating your worries about "strings". But I've not
detected anything like that myself. I reply/respond to what people write
when I have a chance and when I'd like to make a comment or response. If I
don't respond it is because either I was busy/distracted/forgot or I felt
there was nothing I wanted to say.

FWIW I live a long way from London and the SE of England. I belong to the
AES but never go to any meetings. I don't know most of the people who may
well get together 'down there'. Indeed, a number of the first names you
have mentioned here (or in emails to me) are either people I've never
spoken to, or I simply don't know who they are! :-)

As I've said, I just take a hobby interest in audio these days, and that
extends to my writing about it. [1] So I guess I am simply 'out of the
loop' for any string pulling, smoozing, pals acts, or other backstage
stuff. Not encountered anything like that with the few people I know these
days, anyway. That said, I'd certainly agree that sort thing *did* go on to
my knowledge a few decades ago when I worked in the biz. So for all I know
similar things may happen nowdays. But I've not experienced it or been
aware of it whilst writing for HFN.

Slainte,

Jim

[1] FWIW I spend as much time gardening as I do on music/hifi/writing
during a lot of the year. This isn't the right group to chat about it,
although I do recommend it. Lovely mix of enjoyable activities and
appreciating the sights, scents, and sounds of a garden. One particularly
nice thing about our garden is an unexpected side-effect of my wish to try
and get 'flowers all year round'. This is that we get lots of bumble bees.
I only found out after I'd been gardening for a few years that bumble bees
don't store honey to the same extent as honey bees, so rely on being able
to find flowers for a much longer portion of the year! I also didn't know
just how many varieties of bumble bee there are until I started looking.

One bush we have I call "the kazoo bush" because at this time of year the
bees vibrating the flowers sounds like a kazoo orchestra. Also nice to
have blackbirds following me about to leap on any insects I uncover for
them.

And no, I *don't* listen to music in the garden. No 'portable music
player'. I listen to the *garden*. That's where I'm off to, now... :-)

--
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

"David Looser" wrote in message
...
"Fed Up Lurker" wrote

You Dave won't get the gist of this one

(I did add a "yet" which you snipped)

On the contrary I get the "gist" of it only too well!

Do you? I doubt it, if so then briefly explain the "gist" of "piggy-backed"
TDA1543 dac chips. And specifically that chip, what is the "gist" of
piggy-backing (or daisy chaining) that specific tda1543 chip in NONOS mode?
If you do get the "gist" you'll be able to explain it in one sentence.


the essense of how it works and why is sounds as it does is simply
bypassing the filter.

Just that?, you don't replace the bypassed digital filter with an analogue
one?

Nope!
But not a good idea to try NONOS playback through a narrow band
ugly shoebox of the 80's.


So Dave, because you never heard of it dosen't mean it never existed.

Heard of what? If you mean non-oversampled audio DACs I heard of them
about 40 years ago!

Did you? Hey Dave, you make a lot of claims. Now on this subject give
one example of a non-oversampled "audio DAC" from 40 years ago (1970)
that you could have heard about back then. Get googling and try not to be
frantic.
We are talking about 16 binary digit CD playback.
With 16bit playback there have been a number of filter implementations
apart from brickwall - .Bessel elliptic stopband Butterworth blah blah.
And all those filter/non-filter options are frequently offered with
"safe" 24 bit conversion. But you didn't know that?
As for NONOS, you Dave convienently forget it was you who said that
it dosen't exist and cannot work? But it does!


Arny is going to give it a try, and obviously Jim is beguiled by the
whole
concept. Unfortunately this group is too narrow so any more info will
be on a need-to-know basis.

Ah yes! your preference for dropping hints about things rather than saying
what you mean. I'd noticed that you like to do that :-). Makes you feel
superior does it?

David.


Are you feeling a little out of your depth?
We're not excluding you or anyone else out of spite, but you're just
not upto it and you do get frazzled.
And relax.....

"Fed Up Lurker" wrote in message
...

"David Looser" wrote in message
...
"Fed Up Lurker" wrote

You Dave won't get the gist of this one

(I did add a "yet" which you snipped)

On the contrary I get the "gist" of it only too well!

Do you? I doubt it, if so then briefly explain the "gist" of
"piggy-backed"
TDA1543 dac chips. And specifically that chip, what is the "gist" of
piggy-backing (or daisy chaining) that specific tda1543 chip in NONOS
mode?
If you do get the "gist" you'll be able to explain it in one sentence.



Hi Dave
Just before I go off line for a couple of days, well I'm feeling beneficial
and gentle toward you and I don't want you spending hours googling
trying to find counter arguments that are wrong, so I'll explain it
(briefly):
The TDA1543 (Being what PMi originally identified as a hybrid thingy)
when piggy-backed/daisy chained the 1543 actually acts as a type of filter.

With NOS'ing I disable/by-pass the *pre-conversion* digital filter.
The analog output sector remains as is, and that is for system
compatibility.
Thats NONOS.

The "gist":
But with the piggy-backed *TDA1543*, the quantization unltrasonic hash
is pushed out of the audioband with each step of the daisy chain, so
it is a form of oversampling not pre-conversion nor in post analog output,
but a stepped version *DURING* conversion.
So though in effect there is no filter pre-conversion, and technically that
can be called NONOS, with eight TDA1543's piggy-backed (four per
stereo channel) that is in effect 4 x o/s but *During* conversion.
And as for a NOS'er such as myself, thats not NONOS, regardless
of marketing laws that allow them to call it that.
Now Dave try and get some rest and look out for Jim's articles on the
subject on his site and in HFN+RR sometime near xmas.

I don't know why, but for some strange reason I feel compelled to
mention that "trendy" DAC to end this post, but I'll resist the urge.....

Toodle pip.

"Jim Lesurf" wrote in message
...
In article , Fed Up Lurker
wrote:
[snip]


I am interested and do plan to do some closer examination and comparisons
sometime. But do have loads of other things on the same 'to do' list. :-)

Understood it is a case of having priorities Jim.
I just got the Sept HFN+RR issue, your self authored software looks
interesting,
I might give it a try out.


I don't think Jim is talking to me anymore, I think he finds me too
annoying and maybe strings have been pulled?

You do seem to keep repeating your worries about "strings".

They are not "worries" as such, it happens and we know it.

But I've not detected anything like that myself.

emm........

I reply/respond to what people write when I have a chance and when
I'd like to make a comment or response. If I don't respond it is because
either I was busy/distracted/forgot or I felt there was nothing I wanted
to say.


I've grabbed your attention, I have faith in you to follow it up, no rush.


FWIW I live a long way from London and the SE of England. I belong to the
AES but never go to any meetings. I don't know most of the people who may
well get together 'down there'. Indeed, a number of the first names you
have mentioned here (or in emails to me) are either people I've never
spoken to, or I simply don't know who they are! :-)

.....Pants on fire


As I've said, I just take a hobby interest in audio these days,

That is just fine, it's we hobbiests who know what we are doing!

and that extends to my writing about it.

Amazing coincidence, my hobby is writing about it too, but I like
to be confrontational and a touch of attack can be fun, you should
try those approaches in your column sometimes....

So I guess I am simply 'out of the loop' for any string pulling, smoozing,
pals acts, or other backstage stuff. Not encountered anything like that
with the few people I know these days, anyway.

Phew! Have I got some tales to tell you ... in email though.


FWIW I spend as much time gardening as I do on music/hifi/writing
during a lot of the year.

We used to have gardens in the SE, long gone now....

This isn't the right group to chat about it, although I do recommend it.
Lovely mix of enjoyable activities and appreciating the sights, scents,
and sounds of a garden.
One particularly nice thing about our garden is an unexpected side-effect
of my wish to try
and get 'flowers all year round'. This is that we get lots of bumble bees.
I only found out after I'd been gardening for a few years that bumble bees
don't store honey to the same extent as honey bees, so rely on being able
to find flowers for a much longer portion of the year! I also didn't know
just how many varieties of bumble bee there are until I started looking.


Genuinely, it sounds perfect.

One bush we have I call "the kazoo bush" because at this time of year the
bees vibrating the flowers sounds like a kazoo orchestra. Also nice to
have blackbirds following me about to leap on any insects I uncover for
them.

That sounds blissful, but here in London we have a problem with urban foxes
which are getting a tad brazen, beautiful animals but the problem is humans
who feed the foxes which now approach anyone who stands still and beckons,
as the foxes now correlate friendly humans with an easy food supply.
You are probably aware of the horror stories of night time attacks etc, of
foxes intruding into residential properties in search of some grub.


And no, I *don't* listen to music in the garden. No 'portable music
player'. I listen to the *garden*. That's where I'm off to, now... :-)

I don't listen to music on portable media players either, and just thinking
about that as a subject, I realised I now rarely listen to music in the car
either these days. (VW with self rigged Pioneer + JBL)
I'm out of time and have to go
Cheers.

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

On Wed, 28 Jul 2010 09:29:14 +0100, Jim Lesurf wrote:

In article , Peter Chant
FWIW later tests and all listening have been with 4 x NiMH AA (1700mAh)
cells as the power supply. These have so far lasted a couple of hours but
I've no idea how much longer they will manage before needing a recharge.

You could run the thing while logging the power drain and when the Voltage drops to 2
or perhaps just 2,5 V just note the time it took to get there. If you have a way to
alert you when a certain Voltage is reached or a way to automatically log voltage
over time.
Or just run it on a speaker so you can hear when it shuts down, and set your
wris****ch alarm for every half hour and read and write down the voltage. I am sure
it doesn't have to be scientific logging. Unless you got equipment that can automate
the process. (That or a teenager in the house with nothing better to do this summer).

-Mikkel

the essence of how it works and why is sounds as it does is simply
bypassing the filter.

Just that?, you don't replace the bypassed digital filter with an
analogue one?



Heard of what? If you mean non-oversampled audio DACs I heard of them
about 40 years ago!

Did you? Hey Dave, you make a lot of claims. Now on this subject give
one example of a non-oversampled "audio DAC" from 40 years ago (1970)
that you could have heard about back then. Get googling and try not to be
frantic.

Hi Dave
I wasn't holding my breathe for your example of a 40 yr old NONOS dac.
And I really shouldn't do this, but last night I read through the latest
edition of a HiFi mag, it being the best of the bunch, but disappointing
nonetheless but that's for email.
And this is pathetic of me, I'm a shift worker on lates this week and
I had determined to break from the webby thing for a while but as there
is no "TheWrightStuff" and it's an hour until Trisha, yep I logged in here..
This morning I remember parts of my dream, at least it was about Anne
Diamond and Kirsty Young, but that's for another group. But this morning
the first thing running around in my head is the stuff you Dave come out
with.
Hey Dave, you are an annoying bluffer, your provocative technique is almost
impressive if it wasn't for the fact you don't get your facts right?
You have to admit it was a bit silly to claim you "heard" of NONOS audio
dacs 40 yrs ago, but when this topic started in this group you had never
heard of it!
And you keep referencing a need for analogue filtering when no digital
filter - Totally pointless, and very Wrong!
I've just briefly read through the thread, it seems by time and date of
posts that you only mentioned analogue filtering once Jim and I touched
on the subject? So I'll explain....

NONOS. NON O/S. Non over-sampling DAC:
The point of oversampling as identified graphically many years ago
by PMi is that ultrasonic hash that is just outside the audioband is
pushed up and away in steps - 2x o/s, 4 x o/s etc.
Primarily this is for system compatibility issues, but also back in those
early days of CD, for the issues with the then yet to evolve digital
recording techniques employed or the transfer of analogue masters
to digital (and those techniques to digitally record and transfer to CD
are another very convoluted subject).
Again I'm going to cite PMi, he identified that without digital filtering
that ultrasonic hash may "envelope" back into the audioband, and now
I'm going to cite me again, with the right recording and the right system
(Not an over-priced ugly shoebox of the 80's) that "enveloping" can have
a "magical" effect.
If for the sake of your insisted (but wrong) argument we look at if it
cannot work without analogue filtering - how would that work?
If I bypass pre-conversion digital filtering, and spuraie "envelopes" into
the audioband, then it is there through conversion, there is no subsequent
filtering of any type that can undo that.

Discuss.

PS. So Dave what have you got planned for today, are you into gardening?
Do you live in or near London, interested in hearing a NONOS'd cd player?

In article , Mikkel Breiler
wrote:
On Wed, 28 Jul 2010 09:29:14 +0100, Jim Lesurf
wrote:

In article , Peter Chant FWIW later
tests and all listening have been with 4 x NiMH AA (1700mAh) cells as
the power supply. These have so far lasted a couple of hours but I've
no idea how much longer they will manage before needing a recharge.

You could run the thing while logging the power drain and when the
Voltage drops to 2 or perhaps just 2,5 V just note the time it took to
get there.

[snip]

Afraid I'm not that organised at present. Indeed, I don't think I ever
am... [1] :-)

I've just been keeping a mental note to see if it 'lasts OK' or I find they
need recharging annoyingly often. If I get a chance I'll simply measure the
current drain once or twice and extrapolate an estimate. Then update the
webpage with this and any other extra info I've collected.

Slainte,

Jim

[1] This morning distracted by writing a simple Linux ROX app for making
burning video dvds easier.

--
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