After the “James May moment” with my ESI Juli@ a lot of internet reading was embarked upon to source a card which would fit the motherboard and also provide high quality audio for the radio setup.
http://telepostinc.com was a good source of review material for the various cards out there and is geared towards SDR. It’s becoming very evident that as PC technology moves on, soundcards are lagging behind and all the really good products for SDR radio made by ESI, M-Audio’s Delta 44 etc aren’t available in a PCI-e format. There’s also a lot of posts out there where people report issues when installing PCI soundcards into motherboards which also have a PCI-e slot amongst those available for use. The upshot being that they don’t work!
Don’t get me wrong there are some awesome products on the marked for audiophiles, but you then end up with connectivity issues between the radio and the PC which just adds to the headache.
Ironically when I was playing with my WSPR receiver back in the summer and bought my Soundblaster Live 24 USB card I also looked at the Xonar DX card and commented on it. Admittedly that was the PCI version and I would have been in the same boat now had I bought it then, but thankfully they do a PCI-e variant so I’ve invested in one of them.
There are fellow SoftRock owners using them successfully if you believe the forum posts, so its worth a go!
The only evident nag is Asus’s lack of enthusiasm in providing updated drivers for this card and equally hiding them away on their site. To assist here’s the link
A bit more digging revealed there is a third party set of drivers available from maxedtech.com who are serious about their audio. These are available at this site
This afternoon was spent plumbing the new card in (I’ve now got three soundcards in this box which is extreme but needed) which was a bit fiddly due to the size of my machine case more than anything.
I was very tempted to go with the third party unified drivers but when they crashed during installation I hurriedly reverted to the latest Asus version and sat and tapped my fingers while they installed.
All appears well apart from a minor calibration issue with SDR Console. I’ve got a lovely 192kHz spectrum sample which is being mirrored around a central peak which is really really odd.
I’ve looked everywhere for some sort of setting within the program to “switch something off or on” and am absolutely stumped as to what needs tweaking. Equally I’m stumped as to whether it’s a soundcard setting within Windows which is causing the artefact.
HDSDR doesn’t seem to be suffering the same issue which is very odd. Admittedly there are heavy transmission bands to the left and right extremes of the spectrum but if you look at the intermediate signals, they’re not a mirror image.
I’m sure we will divide and conquer at some point!
Within an hour of posting this and banging my head against a virtual wall a bit more, I’ve sussed it!
The Xonar DX has a combined SPDIF out and line in port. When you select the line in option within software you can hear the physical click of a relay on the board where it must be changing over. When you select the Line In (Asus Xonar XD) soundcard option within SDR Console, for some reason it’s not doing that change over and is defaulting to Aux in (Asus Xonar XD) which is giving the mirrored spectrum.
When you select the various soundcard options within HDSDR the changeover is instant. Going back to SDR Console, now when you select the Line In option it appears to be working ok.