Top dB nonlinearity?

[Guest]

Archived from groups: rec.audio.pro (More info?)

Hi folks:

Anyone here familiar with the AD1853 D/A converter chip? Does it have a
linearity problem in the top decibel (in other words, significantly higher
distortion from -1.0dBFS to 0dBFS)?

What about the AD1896 asynchronous sample rate converter? Does it have the
problem outlined above?

Peace,
Paul

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Paul Stamler <pstamlerhell@pobox.com> wrote:
>
>Anyone here familiar with the AD1853 D/A converter chip? Does it have a
>linearity problem in the top decibel (in other words, significantly higher
>distortion from -1.0dBFS to 0dBFS)?
>
>What about the AD1896 asynchronous sample rate converter? Does it have the
>problem outlined above?

I do not know about the AD1853, but my experiences with the AD1896 and AD1893
converter chips have been good ones and didn't show any such evilness.

If the 1853 uses an external I/V stage, I might try replacing that with a
fixed resistor and fiddling with the resistor values for best linearity.
--scott

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

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Hey Paul , i've worked under the idea that most convertors lose linearity
in
the top & bottom of their ranges , and as a reminder that a few db of
headroom
doesn't hurt [ well maybe 60 hurts with a hammer ! ]

Are you planning a convertor project ?

regards Greg


"Paul Stamler" <pstamlerhell@pobox.com> wrote in message
news:a1Vmd.31595$7i4.3482@bgtnsc05-news.ops.worldnet.att.net...
> Hi folks:
>
> Anyone here familiar with the AD1853 D/A converter chip? Does it have a
> linearity problem in the top decibel (in other words, significantly higher
> distortion from -1.0dBFS to 0dBFS)?
>
> What about the AD1896 asynchronous sample rate converter? Does it have the
> problem outlined above?
>
> Peace,
> Paul
>
>

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

"GKB" <gboboski@shaw.ca> wrote in message
news:YU2nd.255688$Pl.208407@pd7tw1no...
>
> Hey Paul , i've worked under the idea that most convertors lose linearity
> in
> the top & bottom of their ranges , and as a reminder that a few db of
> headroom
> doesn't hurt [ well maybe 60 hurts with a hammer ! ]
>
> Are you planning a convertor project ?

Nope, testing a commercial product. At -1.1dBFS and below it's unbelievably
clean, but from -1.0dBFS on up it produces surprising levels of HF IM
distortion, especially on a 3-tone test..

Peace,
Paul

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

"Paul Stamler" <pstamlerhell@pobox.com> wrote in message
news:Lj5nd.33573$7i4.22943@bgtnsc05-news.ops.worldnet.att.net

> Nope, testing a commercial product. At -1.1dBFS and below it's
> unbelievably clean, but from -1.0dBFS on up it produces surprising
> levels of HF IM distortion, especially on a 3-tone test..

IME not all that unusual.

Probable cause - clipping in the converter's digital filter.

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

In article <_IWdnS-_8Yr1fwHcRVn-ow@comcast.com>,
Arny Krueger <arnyk@hotpop.com> wrote:
>"Paul Stamler" <pstamlerhell@pobox.com> wrote in message
>news:Lj5nd.33573$7i4.22943@bgtnsc05-news.ops.worldnet.att.net
>
>> Nope, testing a commercial product. At -1.1dBFS and below it's
>> unbelievably clean, but from -1.0dBFS on up it produces surprising
>> levels of HF IM distortion, especially on a 3-tone test..
>
>IME not all that unusual.
>
>Probable cause - clipping in the converter's digital filter.

Look at the bit stream out of the sample rate chip going into the converter
chip. A bitscope would be nice, but you should be able to see what is going
on even with just an oscilloscope. If you put a signal at 1.0 dBFS into the
input, are you seeing FFFF anywhere in the data stream? You shouldn't, you
know.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."