oneinchside
Openly Baffled
Well I wanted a better DAC for listening to 2 channel audio on the 'puter, and I found it... about 1.5cm from my old one.
I had been frustrated with the sound coming out of my PC, actually all of them, and was dreaming of an upgrade to an outboard DAC, but the pennies weren't there. Now, granted, in the world of HiFi a $200 component is a drop in the bucket, but in my current fiscal calendar it is 2.785 years worth of disposable income. Or something like that.
So I started looking for overlooked DACs and something I could mod, in the process I read this regarding the Sound Blaster Live! series:
Rear channel? Oh yeah, it does support one of those... a different DAC? Really? Hmmm....
So I moved that crappy little 1/8" plug from the green spot to the black one, adjusted the balance between the 2, went through and reset all the gain stages in ALSA and Jack (I use Linux, the same works using the Kx drivers in Windows) Shut off all unnecessary services and Voila! It sounds like a whole new source. Thin and quiet? More like accurate and not f'd up.
The flexibility you have in routing devices in Jack and the Kx drivers is simply amazing.
Oh, a few other things-- the Sound Blaster only operates at 16 bit /48 khz. If you play a cd in the drive it'll sound like *bleep* because of the AC97 chip... the data is coming in at 44.1khz and being converted on the fly by the AC97 chip, and poorly I might add. And then the same chip has to do the DA conversion, and control the mixing/effects and all sound interrupts at the same time. That's a lot to ask of the poor ol' chip.
But by recording a CD by a direct bit copy to the HD and then using Audacity to upconvert it to 48khz... then the AC97 chip doesn't have to do any thinking really, just routing. And by having the (nicer) Phillips UDA1334 DAC do the digital-analog chores it has all of that off it's mind... and this case that's a good thing. The only other stage that could get in the way of the 1334 is the "3D" effects-- turn those things off in the ALSA mixer.
So everything is perfect right? Not quite. Making a bit for bit copy takes a while, and a high quality conversion takes a lot longer. (2+ hours for a 5 min song on my machine). And the OPAMP that follows the 1334 is small, and weak, and the attendant caps are... small and cheap.
Still it's a heck of a lot less shrill and smeary. Reverb sounds like reverb, a delayed copy of the original signal, rather than a nasty unexplained glare. Still, its a HUGE step forward, and considering that there has been a SB derivative in almost every "normal" PC I figure this should help a few others. And finally, it sounds just about as good as my Magnavox MWD200G DVD player. (it's not a very high bar folks, but not being able to best a $29 DVD player from the drug store really chapped my hindparts.)
Now, if I just took that teeeny tiny analog signal fresh from the 1334 and fed to a nice tube output stage...
Questions, pictures, links, references, pinouts, etc, just ask if ya need 'em.
I had been frustrated with the sound coming out of my PC, actually all of them, and was dreaming of an upgrade to an outboard DAC, but the pennies weren't there. Now, granted, in the world of HiFi a $200 component is a drop in the bucket, but in my current fiscal calendar it is 2.785 years worth of disposable income. Or something like that.
So I started looking for overlooked DACs and something I could mod, in the process I read this regarding the Sound Blaster Live! series:
Rear channel? Oh yeah, it does support one of those... a different DAC? Really? Hmmm....
So I moved that crappy little 1/8" plug from the green spot to the black one, adjusted the balance between the 2, went through and reset all the gain stages in ALSA and Jack (I use Linux, the same works using the Kx drivers in Windows) Shut off all unnecessary services and Voila! It sounds like a whole new source. Thin and quiet? More like accurate and not f'd up.
The flexibility you have in routing devices in Jack and the Kx drivers is simply amazing.
Oh, a few other things-- the Sound Blaster only operates at 16 bit /48 khz. If you play a cd in the drive it'll sound like *bleep* because of the AC97 chip... the data is coming in at 44.1khz and being converted on the fly by the AC97 chip, and poorly I might add. And then the same chip has to do the DA conversion, and control the mixing/effects and all sound interrupts at the same time. That's a lot to ask of the poor ol' chip.
But by recording a CD by a direct bit copy to the HD and then using Audacity to upconvert it to 48khz... then the AC97 chip doesn't have to do any thinking really, just routing. And by having the (nicer) Phillips UDA1334 DAC do the digital-analog chores it has all of that off it's mind... and this case that's a good thing. The only other stage that could get in the way of the 1334 is the "3D" effects-- turn those things off in the ALSA mixer.
So everything is perfect right? Not quite. Making a bit for bit copy takes a while, and a high quality conversion takes a lot longer. (2+ hours for a 5 min song on my machine). And the OPAMP that follows the 1334 is small, and weak, and the attendant caps are... small and cheap.
Still it's a heck of a lot less shrill and smeary. Reverb sounds like reverb, a delayed copy of the original signal, rather than a nasty unexplained glare. Still, its a HUGE step forward, and considering that there has been a SB derivative in almost every "normal" PC I figure this should help a few others. And finally, it sounds just about as good as my Magnavox MWD200G DVD player. (it's not a very high bar folks, but not being able to best a $29 DVD player from the drug store really chapped my hindparts.)
Now, if I just took that teeeny tiny analog signal fresh from the 1334 and fed to a nice tube output stage...
Questions, pictures, links, references, pinouts, etc, just ask if ya need 'em.
