Hi Ablerto!
> Hi Janne, > >I read that series of messages, and I found really strange that such >a high quality sound card can shift by 60 degrees one of the two >channels... I would suspect a defective card. > >I can report my experience. I was loaned for a test the EMU-1616M >Laptop Digital Audio System (an external box and a PCMCIA card), and >I used it with my laptop and Winrad, using the ASIO drivers. It was >really a good, very good, sound card... it was with regret that I had >to return it to the guy from whom I had the loan... sampling at 192 >kHz it was beautifully flat along almost all the range, and the noise >also was quite low. I did not take screen captures, regretfully... >what I did not do was to test it with the Windows MME drivers to >check if there was any difference. Were it not for the price, I would >consider it the almost ideal card for an SDR. > Well, this is very encouraging. At least I might have really really good audio card for SDR. Actually, I bought it originally for the music stuff, but the SDR was the reason for choosing 192kHz card. >Surely. A good external USB audio adapter is the Alesis IO|2 unit. >Look here : http://www.alesis.com/product.php?id=8 >I own one, and must say that the flatness of the response and the >background noise are similar, if not better, to those of the Delta >44. Its big cons is that it can sample only up to 48 kHz and not >beyond. >But, if you can find locally an USB audio adapter that you are sure >performs correctly, without the dreaded "one sample delay" on one of >the two channels, then you can check whether the problems you are >experiencing depend on the QSD hardware or on the sound card. > I'm just thinking, isn't there any other way to find out eather the problem is in the audio card or qsd. Can I feed somekind of test signal to the card and see if the phase is running out etc ? Anyway, I have thought about integrating USB audio card inside the SDR transceiver. No more the lossy audiocables between :) And in that point, I definently will check out Alesis, since I'm already familiar with the brand (my guitar equipment). 73 de Janne Pulkkinen, OH1GTF
