Re: [RTTY] DXP38 vs Soundcard stuff

[Kok Chen <chen@mac.com>]

On Mar 12, 2004, at 4:21 PM, Bill Turner wrote:

> On Fri, 12 Mar 2004 18:54:07 EST, K4FJ@aol.com wrote:
>
> > No sound card solution here and I doubt the sound card beats the
> > DXP38.
>
> _________________________________________________________
>
> You doubt because you haven't run a side by side comparison.  Those who
> have, don't.

My two kopecks:

When you are comparing or use any kind of a device that has a A/D 
converter at the input (e.g., Sound Card, DXP38, etc), it is critical 
that the audio levels are adjusted so as to match the range of the 
converter.  Analog TUs and digital devices with an analog AGC stage 
(Timewave DSP599zx, for example) are less sensitive to poor level 
matching, but only to a certain point.

A DXP38 has a 14-bit A/D converter and a pretty dated TI DSP processor. 
 It stands to engineering reason that a modern fast computer with a 
good 16-bit sound card wins as long as it knows how to make use of all 
that extra processor speed for some good.

You can buy good 20 bit USB converters for less than $40, and you can 
buy very good 24-bit A/D USB converters for less than $100.  I have no 
idea if programs such as MMTTY on a Wintel system can make use of the 
extra bits, but modern OS'es use floating point audio paths and can 
make good use of the extra bits.

73
Chen, W7AY

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