🚀 go-pugleaf

--=}>> On 4 Oct 92 03:50:37 GMT, deanaj@elec.canterbury.ac.nz (A. J. Dean) said:
> Nntp-Posting-Host: betelgeux.canterbury.ac.nz

> Nicolas Alejandro Arauz (na0s+@andrew.cmu.edu) wrote:
> : Maybe someone can answer this question for me:
> : > this, so I'll ask you.  My question that I wasn't sure about was whether
> : > or not ANY of these cards would all simultaneous input/output from the
> : > ADC/DAC do do digital effects?  Or perhaps even switch so fast that you

> I've had a go a doing a similar thing with my soundcard (for guitar
> effects, etc). BTW, it's a SB pro version 1. I think it may be able
> to do simultaneous ADC and DAC (not in DMA mode) but even if it does
> the audio routing/mixing circuitry won't. For a start, you can't
> turn off the input monitor without turning down everything else
> including the DAC, ie you always get some of your original signal
> straight through (though I did think about subtracting it).

Well, this is the case only for the Line and CD audio inputs.  It
seems that the microphone level can be reduced to silence, and it will
still record at normal volume.  It's as if the Mic level does not
adjust the input level, but just the "thru" level.

> Also, selecting the DAC disconnects any sound from the ADC (well, it
> gives random values - could be used as part of the ADC).

Yeah.. You have to turn "DAC Output" off before recording.  They don't
mention that in the Developers' Kit.  The worst part is that it can
take "up to 300 milliseconds"(!) to make the change.  This is probably
a misprint, as it happens much faster on my card.

> You can switch rapidly between ADC and DAC, but the result is pretty
> awful, though it did work. After that I gave up, along with giving
> up on my ultra-optimised 8 bit FIR fiter routines for the PC. I'll
> wait/pay for a soundcard which is a bit less limited!
> Antony. (deanaj@elec.canterbury.ac.nz) 

BTW, does anyone know of a lower-end PC soundcard that CAN do
simultaneous ADC/DAC?  Most of the common ones can't seem to.

-Steve

Steve Haehnichen
shaehnic@ucsd.edu