Hi,

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want 24bit.
Does this mean one has to write one's own ? It's slightly outside my area of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than consumer
btw which I suspect means using separate A/D and D/As.

Graham

lid wrote:

In sci.electronics.design Pooh Bear wrote:
Hi,

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want 24bit.
Does this mean one has to write one's own ? It's slightly outside my area of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than consumer
btw which I suspect means using separate A/D and D/As.

Why USB ..?

Because it's available on almost every PC these days. If I was looking at multichannel
obviously firewire would make sense.

Graham

"Pooh Bear" wrote in message
...
Hi,

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want
24bit.
Does this mean one has to write one's own ? It's slightly outside my area
of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than
consumer
btw which I suspect means using separate A/D and D/As.

Graham

A general purpose ASIO driver does exist.

"Pooh Bear" wrote in message
...
Hi,

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want
24bit.
Does this mean one has to write one's own ? It's slightly outside my area
of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than
consumer
btw which I suspect means using separate A/D and D/As.

Graham


Have you been abducted as well?

"Hi there"

******** more like.

No you don't..... you design power supplies without inductors but you might
be snouting about for some new development that says you can do RAVE(?) over
USB.

DNA

On Sun, 11 Jun 2006 21:05:01 +0100, Pooh Bear
wrote:

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want 24bit.
Does this mean one has to write one's own ? It's slightly outside my area of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than consumer
btw which I suspect means using separate A/D and D/As.

There's no shortage of affordable boxes that do this. Do you need to
re-invent it? I suppose you could take one apart and see what's in
it.

Laurence Payne wrote:

On Sun, 11 Jun 2006 21:05:01 +0100, Pooh Bear
wrote:

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want 24bit.
Does this mean one has to write one's own ? It's slightly outside my area of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than consumer
btw which I suspect means using separate A/D and D/As.

There's no shortage of affordable boxes that do this. Do you need to
re-invent it?

If one followed that line of thought I wouldn't design anything would I ? Besides,
no-one's done what I'm planing to offer. The USB interface is actually very much
an add-on extra to something else.

I suppose you could take one apart and see what's in it.

That's not really the way I normally do things. Beside, I don't want to
necessarily use what was possibly state of the art when they were designed maybe
several years back when better may be available.

Graham

Genome wrote:

"Pooh Bear" wrote in message
...
Hi,

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want
24bit.
Does this mean one has to write one's own ? It's slightly outside my area
of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than
consumer
btw which I suspect means using separate A/D and D/As.

Graham

Have you been abducted as well?

"Hi there"

******** more like.

No you don't..... you design power supplies without inductors but you might
be snouting about for some new development that says you can do RAVE(?) over
USB.

What on earth is the matter with you ?

Graham

Look at Ogg Vorbis. If it doesn't handle what you want now, I understand
that its modular and easily extensible.

--
Paul Hovnanian
------------------------------------------------------------------
Life is like a buffet. Its not very good but there's plenty of it.

"Paul Hovnanian P.E." wrote:

Look at Ogg Vorbis. If it doesn't handle what you want now, I understand
that its modular and easily extensible.

Don't want to use a compressed format. It would compromise the rest of the
product.

Graham

On Sun, 11 Jun 2006 22:20:35 +0100, in sci.electronics.design Pooh
Bear wrote:



Laurence Payne wrote:

On Sun, 11 Jun 2006 21:05:01 +0100, Pooh Bear
wrote:

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want 24bit.
Does this mean one has to write one's own ? It's slightly outside my area of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than consumer
btw which I suspect means using separate A/D and D/As.

There's no shortage of affordable boxes that do this. Do you need to
re-invent it?

If one followed that line of thought I wouldn't design anything would I ? Besides,
no-one's done what I'm planing to offer. The USB interface is actually very much
an add-on extra to something else.

I suppose you could take one apart and see what's in it.

That's not really the way I normally do things. Beside, I don't want to
necessarily use what was possibly state of the art when they were designed maybe
several years back when better may be available.

Graham

Have a word with FTDI http://www.ftdichip.com/ they might be able to
pint you somewhere suitable


martin

"Pooh Bear" wrote in message
...

What on earth is the matter with you ?

Graham



Hey, I care.....

You spend most of your time being really pally around here and some of it
taking the **** out of us dumb people...... and designing power supplies
without inductors in them.

Then you come along with....

'Hi'

Like some nube would.. as if you would pretend to be one?

And ask for advice.

This does not work so I thought you might have been abducted.

Note to abductors... This one isn't worth frying so it will cost you more to
keep it alive than it's worth paying for it.

Thanks

DNA

Pooh Bear wrote:

lid wrote:


In sci.electronics.design Pooh Bear wrote:

Hi,

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want 24bit.
Does this mean one has to write one's own ? It's slightly outside my area of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than consumer
btw which I suspect means using separate A/D and D/As.

Why USB ..?


Because it's available on almost every PC these days. If I was looking at multichannel
obviously firewire would make sense.

Not really. USB 2.0 spec is 480Mbps, vs. 400 for standard firewire.
Either should have plenty of bandwidth for a ton of audio channels (we
used to run uncompressed component video - three video streams - to
firewire drives on video-capture stations, so a couple dozen audio
streams should be no problem).

"Bitness" of a Windows USB driver has no relation to how many bits
you're sampling audio at anyway. My "old" USB-interface Soundblaster
Extigy supports up to 96kbit sample rates at 32-bit sample depths, and
it works fine on a USB 1.1 connection (96k/32-bit stereo audio is only a
little over 6 megabits per second, well within USB 1.1's 12Mbit bandwidth).

Pooh Bear wrote:

Genome wrote:


"Pooh Bear" wrote in message
...

Hi,

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want
24bit.
Does this mean one has to write one's own ? It's slightly outside my area
of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than
consumer
btw which I suspect means using separate A/D and D/As.

Graham

Have you been abducted as well?

"Hi there"

******** more like.

No you don't..... you design power supplies without inductors but you might
be snouting about for some new development that says you can do RAVE(?) over
USB.


What on earth is the matter with you ?

Peppermint Schnapps hangover, I'm guessing...

Genome spake thus:

"Pooh Bear" wrote in message
...

What on earth is the matter with you ?

Hey, I care.....

You spend most of your time being really pally around here and some of it
taking the **** out of us dumb people...... and designing power supplies
without inductors in them.

Then you come along with....

'Hi'

Like some nube would.. as if you would pretend to be one?

And ask for advice.

This does not work so I thought you might have been abducted.

Hey, where do you think "experts" go for help? Sometimes experts need
advice from even bigger experts.


--
Any system of knowledge that is capable of listing films in order
of use of the word "****" is incapable of writing a good summary
and analysis of the Philippine-American War. And vice-versa.
This is an inviolable rule.

- Matthew White, referring to Wikipedia on his WikiWatch site
(http://users.erols.com/mwhite28/wikiwoo.htm)

"Genome" wrote in message
...

"Pooh Bear" wrote in message
...

What on earth is the matter with you ?

Graham



Hey, I care.....

You spend most of your time being really pally around here and some of it
taking the **** out of us dumb people...... and designing power supplies
without inductors in them.

Then you come along with....

'Hi'

Like some nube would.. as if you would pretend to be one?

And ask for advice.

This does not work so I thought you might have been abducted.

I agree. There actually is something out there, but I'm not inclined to help
Graham find it.

Yes, but you quote things and I have a bandwidth problem.

"David Nebenzahl" wrote in message
.com...

"Robert Morein" wrote in message
news
I agree. There actually is something out there, but I'm
not inclined to help Graham find it.

You're really a small man, aren't you Morein?

Tiny.

Tiny, tiny, tiny.

"Pooh Bear" wrote
in message

I'm interested in passing stereo audio over USB in both directions.

One means for doing this is the network device model. There are a number of
devices that implement a peer network between two computers over a USB
interface. You can move just about any kind of data there is over a peer
network.

Shift gears to Firewire, and Windows has the required driver built in.

I believe that Windows already has a 16bit driver for this but I want
24bit.

There are a goodly number of 24 bit audio devices that run on USB. AFAIK
they all have to provide their own driver.

Pooh Bear wrote:

"Paul Hovnanian P.E." wrote:

Look at Ogg Vorbis. If it doesn't handle what you want now, I understand
that its modular and easily extensible.

Don't want to use a compressed format. It would compromise the rest of the
product.

Then don't. Or use lossles compression. The protocols are extensible.

--
Paul Hovnanian
------------------------------------------------------------------
Yeah, but you're taking the universe out of context.

Genome spake thus:

Yes, but you quote things and I have a bandwidth problem.

Still using that 2400 baud modem, are you?


--
Any system of knowledge that is capable of listing films in order
of use of the word "****" is incapable of writing a good summary
and analysis of the Philippine-American War. And vice-versa.
This is an inviolable rule.

- Matthew White, referring to Wikipedia on his WikiWatch site
(http://users.erols.com/mwhite28/wikiwoo.htm)

What on earth is the matter with you ?

Peppermint Schnapps hangover, I'm guessing...

Heh... chick drink :-)

Pooh Bear wrote:

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want 24bit.
Does this mean one has to write one's own ?

What am I missing here? It seems that any of the dozens of USB audio
interfaces on the market will handle 24-bit audio in and out. Off the
top of my head, there's the M-Audio Audiophile USB. It comes with
drivers - you don't have to write your own, but you have to use them.

Or are you looking for components that you can integrate into another
product? Maybe you're looking for a development kit like the BridgeCo
BeBob for Firewire only for USB?

On Sun, 11 Jun 2006 23:07:46 -0700, David Nebenzahl wrote:


Genome spake thus:

Yes, but you quote things and I have a bandwidth problem.

Still using that 2400 baud modem, are you?
Making people wade through twenty pages of irrelevent material just
to get to your two clever lines is obnoxious.

Pooh Bear wrote:
I suppose you could take one apart and see what's in it.

That's not really the way I normally do things. Beside, I don't want to
necessarily use what was possibly state of the art when they were designed maybe
several years back when better may be available.

You should. Because basically there are only a couple USB chipsets out
there, which everybody is using. Pick the USB chipset that you see in
a typical product, THEN use their driver. In all probability, the driver
is going to be provided by the chip manufacturer anyway and they should
have full driver source available on their web site.

For Firewire, most folks are using the TI GPLynx2 chipset. For USB 1.0,
the popular ones were the TI USB3200 and TAS1020B. I don't know who is
making the USB 2.0 audio chipset of highest popularity today.
--scott


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

Mike Rivers wrote:

Pooh Bear wrote:

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want 24bit.
Does this mean one has to write one's own ?

What am I missing here? It seems that any of the dozens of USB audio
interfaces on the market will handle 24-bit audio in and out. Off the
top of my head, there's the M-Audio Audiophile USB. It comes with
drivers - you don't have to write your own, but you have to use them.

I'm not looking to buy one.

Or are you looking for components that you can integrate into another
product?

You got it.

Maybe you're looking for a development kit like the BridgeCo BeBob for Firewire
only for USB?

Something simpler than that actually. There's several chips available for 16 bit
stereo over USB but I've yet to see a 24 bit one. There's a few available for
Firewire too @ 24 bit. Makes me wonder how the various commercial products out
there already do it ( over USB ).

Graham

Scott Dorsey wrote:

Pooh Bear wrote:
I suppose you could take one apart and see what's in it.

That's not really the way I normally do things. Beside, I don't want to
necessarily use what was possibly state of the art when they were designed maybe
several years back when better may be available.

You should. Because basically there are only a couple USB chipsets out
there, which everybody is using. Pick the USB chipset that you see in
a typical product, THEN use their driver.

It may come to that. I'm finding it tricky to locate much info on the subject.


In all probability, the driver
is going to be provided by the chip manufacturer anyway and they should
have full driver source available on their web site.

For Firewire, most folks are using the TI GPLynx2 chipset. For USB 1.0,
the popular ones were the TI USB3200 and TAS1020B.

For 24 bit ? I recall speaking to TI and they said their stuff was only designed for
16.


I don't know who is making the USB 2.0 audio chipset of highest popularity today.

If anyone *does* know !

Graham

"Pooh Bear" wrote ...
Scott Dorsey wrote:
For Firewire, most folks are using the TI GPLynx2 chipset.
For USB 1.0, the popular ones were the TI USB3200 and
TAS1020B.

For 24 bit ? I recall speaking to TI and they said their stuff
was only designed for 16.

All modern computer equipment is designed for 8 or 16 or 32 bit.
It is the firmware/software that decides how to handle 24 bit data
in the conventional 16-bit world.

I don't know who is making the USB 2.0 audio chipset of
highest popularity today.

If anyone *does* know !

Clearly the people making the equipment know.
My own employer may be the primary vendor for all
I know.

"Pooh Bear" wrote in message
...
Hi,

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want
24bit.
Does this mean one has to write one's own ? It's slightly outside my area
of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than
consumer
btw which I suspect means using separate A/D and D/As.

I personally have a sound card with optical digital inputs and outputs and
leave the A/D and D/A to my audio gear. You can find USB sound cards with
digital audio inputs and outputs (both optical type SPDIF and RCA type
TOSLINK).

For A/D and D/A I'm using a Sony minidisc deck. If you hit record when
there isn't a MD in the deck, it does both A/D and D/A conversion. The
input button lets you switch between the analog and digital inputs. Of
course, you can buy external A/D and D/A converters, or use the ones that
exist on many modern amp/receiver/surround sound systems.

Jeff
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety"
- B. Franklin, Bartlett's Familiar Quotations (1919)

"Pooh Bear" wrote ...
Something simpler than that actually. There's several chips
available for 16 bit stereo over USB but I've yet to see a
24 bit one. There's a few available for Firewire too @ 24
bit. Makes me wonder how the various commercial products
out there already do it ( over USB ).

It is simple enough with a few lines of code in the firmware
(on the hardware end) and a few more lines of code in the
device driver. No different, really, than the implementation
of any codec meant to code/decode 24-bit (or 32-bit for
that matter) audio files. For 24-bit, you have your choice
of either packing the two 24-bit values into three 16-bit
words, or wasting a bit of bandwidth and tossing them into
four 16-bit words.

Mike Rivers wrote:
Pooh Bear wrote:

Something simpler than that actually. There's several chips available for 16 bit
stereo over USB but I've yet to see a 24 bit one.

Well, there are certainly plenty of 24-bit USB audio devices. They
couldn't ALL be lying to us, could they?

No, they are just sending alternating 16-bit words. That's why you need
a special driver, of course.
--scott


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

An interesting study of what components are used in modern
consumer electronics can be reviewed here...
http://electronicproducts.com/whatsinside

Each month they feature the summary of a "teardown" of various
products (and a back-list of ~20 previous studies). For example,
currently they feature the annotated parts list of the Dell Inspiron 1200
laptop PC.

Richard Crowley wrote:

"Pooh Bear" wrote ...
Scott Dorsey wrote:
For Firewire, most folks are using the TI GPLynx2 chipset.
For USB 1.0, the popular ones were the TI USB3200 and
TAS1020B.

For 24 bit ? I recall speaking to TI and they said their stuff
was only designed for 16.

All modern computer equipment is designed for 8 or 16 or 32 bit.
It is the firmware/software that decides how to handle 24 bit data
in the conventional 16-bit world.

A dedicated USB audio chipset *does* make the distinction though.

Grahan

Jeff Findley wrote:

"Pooh Bear" wrote in message
...
Hi,

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want
24bit.
Does this mean one has to write one's own ? It's slightly outside my area
of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than
consumer
btw which I suspect means using separate A/D and D/As.

I personally have a sound card with optical digital inputs and outputs and
leave the A/D and D/A to my audio gear. You can find USB sound cards with
digital audio inputs and outputs (both optical type SPDIF and RCA type
TOSLINK).

For A/D and D/A I'm using a Sony minidisc deck. If you hit record when
there isn't a MD in the deck, it does both A/D and D/A conversion. The
input button lets you switch between the analog and digital inputs. Of
course, you can buy external A/D and D/A converters, or use the ones that
exist on many modern amp/receiver/surround sound systems.

I'm effectivly *designing* a sound card - not in the market to buy one.

Graham

Richard Crowley wrote:

"Pooh Bear" wrote ...
Something simpler than that actually. There's several chips
available for 16 bit stereo over USB but I've yet to see a
24 bit one. There's a few available for Firewire too @ 24
bit. Makes me wonder how the various commercial products
out there already do it ( over USB ).

It is simple enough with a few lines of code in the firmware
(on the hardware end) and a few more lines of code in the
device driver. No different, really, than the implementation
of any codec meant to code/decode 24-bit (or 32-bit for
that matter) audio files. For 24-bit, you have your choice
of either packing the two 24-bit values into three 16-bit
words, or wasting a bit of bandwidth and tossing them into
four 16-bit words.

Unforunately, writing device drivers is a bit beyond my current abilities. I'm
looking for something 'off the shelf' really.

Graham

Mike Rivers wrote:

Pooh Bear wrote:

I'm not looking to buy one.

Maybe you should, then open it up to see what's inside. (then try to
rerturn it for a refund g)

Something simpler than that actually. There's several chips available for 16 bit
stereo over USB but I've yet to see a 24 bit one.

Well, there are certainly plenty of 24-bit USB audio devices. They
couldn't ALL be lying to us, could they?

One hopes not ! Maybe the easiest way is indeed to look inside. I expect the likes of
Creative have their own chips though.

Graham

Pooh Bear wrote:

Unforunately, writing device drivers is a bit beyond my current abilities. I'm
looking for something 'off the shelf' really.

And THAT, in short, is why you need to steal someone else's design. Find
something you like and copy it.
--scott

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

"Pooh Bear" wrote in message
...
I'm effectivly *designing* a sound card - not in the market to buy one.

I know, but I fail to see the point when there are many affordable USB sound
cards with digital audio inputs and outputs. Plus, I prefer optical digital
connections to keep the electrically noisy PC completely electrically
isolated from my audio equipment.

If I were you I'd concentrate on the high end A/D and D/A parts of the
circuit and use an existing USB sound card with digital inputs and outputs
to drive it.

Jeff
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety"
- B. Franklin, Bartlett's Familiar Quotations (1919)

Pooh Bear skrev:

Jeff Findley wrote:

"Pooh Bear" wrote in message
...
Hi,

I'm interested in passing stereo audio over USB in both directions.

I believe that Windows already has a 16bit driver for this but I want
24bit.
Does this mean one has to write one's own ? It's slightly outside my area
of
expertise. I'd aslo be interested in how Macs support this function.

Any general advice about implementing this, recommended chips etc is very
welcome. The quality needs to be high-end / professional rather than
consumer
btw which I suspect means using separate A/D and D/As.

I personally have a sound card with optical digital inputs and outputs and
leave the A/D and D/A to my audio gear. You can find USB sound cards with
digital audio inputs and outputs (both optical type SPDIF and RCA type
TOSLINK).

For A/D and D/A I'm using a Sony minidisc deck. If you hit record when
there isn't a MD in the deck, it does both A/D and D/A conversion. The
input button lets you switch between the analog and digital inputs. Of
course, you can buy external A/D and D/A converters, or use the ones that
exist on many modern amp/receiver/surround sound systems.

I'm effectivly *designing* a sound card - not in the market to buy one.

Graham

how about getting one of these for inspiration?:
http://www.ramelectronics.net/html/audiophile-usb.html

-Lasse

Jeff Findley wrote:

"Pooh Bear" wrote in message
...
I'm effectivly *designing* a sound card - not in the market to buy one.

I know, but I fail to see the point when there are many affordable USB sound
cards with digital audio inputs and outputs.

I'm not making one of those am I ?

Plus, I prefer optical digital connections to keep the electrically noisy PC
completely electrically
isolated from my audio equipment.

Quite sensible.

If I were you I'd concentrate on the high end A/D and D/A parts of the
circuit and use an existing USB sound card with digital inputs and outputs
to drive it.

That won't fit my target market. Also is a clumsy implementation.

I do wish ppl wouldn't keep saying don't bother, use something else btw. I don't
want to give away my 'secrets' but all I want is a USB audio interface to
incorporate in something else.

Graham

Scott Dorsey wrote:

Pooh Bear wrote:

Unforunately, writing device drivers is a bit beyond my current abilities. I'm
looking for something 'off the shelf' really.

And THAT, in short, is why you need to steal someone else's design. Find
something you like and copy it.

I doubt that selling someone else's device driver would be legal though.

Graham