Dynamic Range...?

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Lyra said:
My thoughts was that a truncaded 20->18bit signal could! be worse than a "low end 18-bit ADC", or a 16-bit signal...!???
As far as I know (they told me...) the engineers at Lexicon have tried to replace CS5389 with CS5390...the closest chip available today with no luck...
CS5390 is 20-bit...and pin to pin compatible with CS5389 as far as I know.

When it comes to CS5396: what a £$&ck is psychoacoustic output ???...don't understand this part.....yet...:confused:

As far as TAS3103A concerned, I just might try this appoach....
A lot of unneccesary functions though...but can be matched with whatever ADC I want to choose...big advantage !!:D


Many devices get away with a 2 bit truncation. The Audionote DACs for a start.
 
Meaningless post, perhaps.

But being that we are talking about an expensive and highly sough-after piece of gear, there has to be sombody (not necessarily here) that can help. I googled. Nothing. I cannot believe this.

I will talk to a friend into these things tomorrow. I'll be meeting him anyway. Don't expect anything. But this bugs me.
 
Lyra said:


This unit uses AD1865 as DAC after the DSP-unit...

Lyra


CS5389 ADC. AD1865 DAC. Not exactly a bargain basement design then. To think you would defile it with a CS5330A. They used to burn people for less than that.

If it was available I'd try out the CS5390. It has exactly the same pinout as the CS5389. Failing that, I'd use the CS5396.
 
rfbrw said:



...If it was available I'd try out the CS5390. It has exactly the same pinout as the CS5389. Failing that, I'd use the CS5396.

The CS5390 has been tried by the guys at Lexicon, and it do not work...I was told !

When it comes to CS5396 I can't figure out what psykoacoustic output is. :confused: It seems like something that could be changed when it comes to number of bits, but I don't understand if this is the audiosignal, or something meant for stearing of some kind of DSP !?
(I can't figure out where to get some of theese either...)


Another approach is to try AD1879 (also obsolete, but available !?) , but I don't have a price in this chip yet. Probably pricey !!? :bawling:
They should work...right?
...with the right pin-adapter of course...

...and TAS3103A...feels something like shooting sparrows with a big cannon...:xeye:



Lyra
 
Lyra said:


The CS5390 has been tried by the guys at Lexicon, and it do not work...I was told !

So they say. They are as capable of making mistakes as anyone else. I'd rather find out myself.


When it comes to CS5396 I can't figure out what psykoacoustic output is. :confused: It seems like something that could be changed when it comes to number of bits, but I don't understand if this is the audiosignal, or something meant for stearing of some kind of DSP !?
(I can't figure out where to get some of theese either...)

The the psychoacoustic output is the dithered and noise shaped bit reduced output. It is used to avoid the effects of simple truncation. The CS5396 just goes that little bit further than most devices in that it allows some control over the noise shaping process. It does require a microcontroller though.


Another approach is to try AD1879 (also obsolete, but available !?) , but I don't have a price in this chip yet. Probably pricey !!? :bawling:
They should work...right?
...with the right pin-adapter of course...

Bought one around 10 yrs ago. Ceramic body, lots of gold and made by Analog Devices. Definitely expensive.


...and TAS3103A...feels something like shooting sparrows with a big cannon...:xeye:

Lyra

But this is a very special cannon. There is still enough of the sparrow left to feed a small cat.
 
Since last time I posted i have found 2 other ADC's that just might could do the job...

#1: Philips UDA1361TS: http://www.semiconductors.philips.com/acrobat_download/datasheets/UDA1361TS_2.pdf

#2: Wolfson WM8782: http://www.wolfsonmicro.com/uploads/documents/en/WM8782.pdf

The Philips part claims that it could do 18-bit output, but I havn't been able to figure out how to set it up for 18-bit (yet...?), and it is a bitstream:dead: converter...that don't exactly make me crazy about it.

The Wolfson part on the other hand have pretty decent data, but this one should probably be set up with 16-bit out, and then (if it's neccesary...) make this data-word act as 18-bit with some glue logic.

Some in here claims that this is not neccesary, but I don't understand that part as this had to be done when they try to make a NONOS DAC with something else than TDA154x's...!? ...for instance AD1865...and this is by the way the DAC at the end of this equipment.
I have to assume that the DSP in this box expect's the data-format in a similar way...especially when the old ADC is configured that way.

When it come to TAS3103A...I feel this one is way above what I understand...had to be configured via I2C for instance...:hot:
Lyra
 
"Misses"? This is one of the most sought after pieces in pro audio. The new PCM91 costs around $2,000. If it had been high-end audio gear, the price would probably have been $20,000.

The PCM90s I have seen for sale all were priced well over $1,000. That's how you know it's good stuff.
 
rfbrw said:



Kit is just another word for equipment. The statement as a whole was referring to the fact that 4 months later the Lexicon is still, at least partially, out of action. Presumably nobody misses it. Or you have a few spare ones.

This is a "state of the art" equipment, and we got several of them.
All in all I think we got allmost 10 (?) in my firm when counting PCM80, PCM81, PCM90, and 91's and of cource some older PCM70's ;)

The only reason that this one is still on my workbench, is that it is broken, and "everyone" in my firm knows that this one is not to be used anytime soon...

Lyra
 
Yes, it is still out of service.
I got several responses from China when searching for the part, but I have not have the time to try to order some of this...
There where prices ranging from 10$/ pcs. to 200$ a piece.
Don't think all of this could be "good" parts, but don't know...:cannotbe:

Lyra
 
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