[Nick Gorham]

Patrick Turner wrote:

Nick Gorham wrote:

TT wrote:

"flipper" wrote in message
...


On Tue, 2 Dec 2008 13:26:05 +0900, "TT"

wrote:



"flipper" wrote in message
om...



Actually, other than Andy's style being perhaps more
clever than
yours, the only thing a "rational observer" could draw

from it is that

neither of you likes each other very much.


The fact is, no one likes Arny very much at all anywhere
;-)
BTW Arny is also a compulsive liar.

Cheers TT


I was going to question the validity of those claims but
Arny is
making your case for you.


I failed to mention his sanity level is variable but you
have already figured that out by now :-)

Cheers TT



Actually, A tube DAC would be easy, use a FPGA to convert from PCM to
delta sigma (still digital), use that to drive a pentode with a low pass
filter on its output, and there you are, the D to A is done by a tube.

(ducks and runs)


We might run right after you and blast your arse with buckshot.

Talk about easier said than done.

Where's your schematic for such a scheme?

Patrick Turner.

--
Nick

Well if you will allow me to draw the FPGA as a black box then should be
simple enough :-)

You would run out of frequency response with a simple CD resolution,
might manage a 8bit converter though.

PCM - PCM to DSigma Converter - Glowing low pass filter

--
Nick

[John Byrns]

In article ,
Nick Gorham wrote:

TT wrote:
"flipper" wrote in message
...

On Tue, 2 Dec 2008 13:26:05 +0900, "TT"

wrote:


"flipper" wrote in message
...


Actually, other than Andy's style being perhaps more
clever than
yours, the only thing a "rational observer" could draw
from it is that
neither of you likes each other very much.


The fact is, no one likes Arny very much at all anywhere
;-)
BTW Arny is also a compulsive liar.

Cheers TT


I was going to question the validity of those claims but
Arny is
making your case for you.


I failed to mention his sanity level is variable but you
have already figured that out by now :-)

Cheers TT



Actually, A tube DAC would be easy, use a FPGA to convert from PCM to
delta sigma (still digital), use that to drive a pentode with a low pass
filter on its output, and there you are, the D to A is done by a tube.

(ducks and runs)

That was one of the three tube DAC techniques that I mentioned I was thinking of
in my earlier post. Each method had a potential problem. The potential problem
with this one is that it has been too long since I was involved in these things
and I couldn't remember how to calculate what rate the one bit pentode DAC would
have to run at in a third order delta sigma converter system to equal CD
resolution. IIRC a first order delta sigma would have to run at about 3 GHz,
probably a little fast for a pentode, to equal CD resolution but IIRC a third
order delta sigma brings that down into the realm of possibility. Anyone know
the actual number?

--
Regards,

John Byrns

Surf my web pages at, http://fmamradios.com/

[Andy Evans]

Andy Evans wrote:
I'm a university lecturer

I have an exceptionally low opinion of those and that was at UCL.

Graham

At UCL in what capacity - lecturing or learning? Or neither?

andy

[Eeyore]

John Byrns wrote:

IIRC a first order delta sigma would have to run at about 3 GHz,
probably a little fast for a pentode

No conventional tube can run that fast. Haven't you studied the subject ?

Graham

[Eeyore]

Andy Evans wrote:

Andy Evans wrote:
I'm a university lecturer

I have an exceptionally low opinion of those and that was at UCL.

At UCL in what capacity - lecturing or learning? Or neither?

As a 1st year undergraduate. I knew more about real world electronics
than the lecturers did. They were living in that fantasy world often
called an 'ivory tower'.

Graham

[Nick Gorham]

flipper wrote:
On Wed, 03 Dec 2008 10:25:39 -0600, John Byrns
wrote:


In article ,
Nick Gorham wrote:


TT wrote:

"flipper" wrote in message
m...


On Tue, 2 Dec 2008 13:26:05 +0900, "TT"

wrote:



"flipper" wrote in message
news:vft8j49gopmetv2515hq5ki6tf90fu1om9@4ax. com...



Actually, other than Andy's style being perhaps more
clever than
yours, the only thing a "rational observer" could draw

from it is that

neither of you likes each other very much.


The fact is, no one likes Arny very much at all anywhere
;-)
BTW Arny is also a compulsive liar.

Cheers TT


I was going to question the validity of those claims but
Arny is
making your case for you.


I failed to mention his sanity level is variable but you
have already figured that out by now :-)

Cheers TT



Actually, A tube DAC would be easy, use a FPGA to convert from PCM to
delta sigma (still digital), use that to drive a pentode with a low pass
filter on its output, and there you are, the D to A is done by a tube.

(ducks and runs)

That was one of the three tube DAC techniques that I mentioned I was thinking of
in my earlier post. Each method had a potential problem. The potential problem
with this one is that it has been too long since I was involved in these things
and I couldn't remember how to calculate what rate the one bit pentode DAC would
have to run at in a third order delta sigma converter system to equal CD
resolution. IIRC a first order delta sigma would have to run at about 3 GHz,
probably a little fast for a pentode, to equal CD resolution but IIRC a third
order delta sigma brings that down into the realm of possibility. Anyone know
the actual number?


I don't think it matters because, if I understood his brief
description, the 'tube' would be simply the last stage filter and you
don't want the filter 'responding' at the bit rate anyway... or else
it isn't 'filtering'.

Yep, the tube would form part of the low pass filter.

I am forcing myself to read some docs though (it was only a off hand
comment), I don't think it would need to. Looking at DSD 2.8MhZ will be
enough, well within a pentodes area, and many triodes for that matter.

--
Nick

[Cipher]

Patrick Turner wrote in
:



LGLA wrote:

"cipher" wrote in message
0...
These seem to be popping up everywhere in audiophile circles..

what would be the purpose of such a device? Yes, I am young and
ignorant re electronics.

something about the whole thing seems counter intuitive to me.

One thing I have noticed about stereo stacks... everything has an
output in one way or another, even if it is the sound itself, from a
speaker. And, the output stage of a DAC would be the point, just for
that tube's worth of sound quality. Any output stage to another
component, is an amplifier.

This is my FIRST post, as a reply, in this NG.

Alex
SoCalifornia

Welcome to our little group. I hope you have a wardrobe full of flame
suits to protect yourself from the barbs, sarcasms, inuendo, and
downright BS that this group generates like mushrooms springing up in
compost.

Between the lines of BS there is much to be treasured here, and if you
increase the treasure then you'll get by better than some.

If you did all the functions of a D to A converters using tubes,
methinks you'd have no room to keep a wife at your house and you'd be
horrified by the power bills. The Green Police would call to arrest
you for causing so much greenhouse gas. Rather a lot of tubes are
needed. However, their purpose would be to perform un-digitalling
tasks which can be done better with zillions of transistors in a chip.
But the tubes are very nice things to use as the fist device to handle
and filter the audio coming from the DA chip.

But soon the digital world will be rocked with DXD etc, so prepare to
say tata to CDs.
The world has always hosted a mix of the best and the worst in any
product. MP3 is the worst, but the DXD could be the best but only for
those who can afford it unless the DXD becomes a real cheap
alternative due to parallel developments in data processing speeds,
memory capacities and broadband data transfer rates.


Put it this way, in 25 years time, will anyone remember how CD players
worked? Will replacement lasers be available? Will anyone know how to
install them? And won't 44kHz x 16 bit all seem even more primitive
than vinyl?

And will we have holographic porno online streaming? and film
character / plot choice? and a host of other gee wizz ways of creating
entertainment without actors, actresses, and orchestras?

Hu nose? I don't. And the future might arrive and I'll be too old to
enjoy it.


Patrick Turner.

There are several benefits to DXD(24 bit word @ 352,8 kHz sample rate) as
a recording and editing medium(such as the allowance for a relaxed ADC
anti-aliasing roll-off filter)but, I do not think it will make a big
splash, personally...a couple of companies use it(Telarc and Lyndberg Lyd
labels are a couple), but the software/hardware required is too expensive
and propreitary..... it is a small niche format for small niche
companies. im guessing it wont do any better than DSD..)

tape and 24/96 etc will reign supreme for a very long time.

[Cipher]

Eeyore wrote in
:

http://www.museumofhoaxes.com/hoax

sir, those aint nothin...

http://www.machinadynamica.com/machina60.htm

http://www.machinadynamica.com/machina31.htm

http://www.belt.demon.co.uk/product/bpaip.html