Cheap USB DAC Audio from a non-audiophile perspective: A review
I have the staple diet Intel D945GCLF2 in my car, and was finding that the audio output quality was pretty low, with clipping on higher frequencies, even from higher bitrate mp3's, and even some FLAC audio that I ripped to test (Thankyou Michael Jackson)
I had read that the output voltage for the onboard audio was quite low, however I didn't want to pick up a PCI soundcard, as I want to use my PCI slot for other purposes.
I started looking around at USB based DAC's....and my wallet self destructed when I saw the prices. $150 plus for a DAC, that only outputs 2 channels? Ouch. I know, I know, you get what you pay for, but I wanted something that I could pick up first as a test.
I had a couple of options here, stump up for a cheap USB DAC from ebay, or try and use an SPDIF to analogue converter. From reading about jitter issues etc that could be had using the SPDIF converter, I thought I would take that as a second option.
So, on to ebay, and I picked up this:
$75 including postage to Australia, from a reputable US dealer. Sounds like a good test piece! And, for that price, it can also be used as an SPDIF converter too, using either optical or coax inputs, or just be the USB DAC.
The only risk was getting too low an output voltage, but hey, anything should be better yes?
The product arrived today in the postage, and I ripped it apart to test it out. There is a spec sheet inside the box, which states that the analogue output is 10Kohm impedance, and 1.35Vrms. Its on the low end I believe, but at least they have specified an RMS value, which doesnt seem to be common these days! It also only supports uncompressed audio, however it does support 24bit, 96khz over the USB interface.
First test, was on my main desktop PC, which uses an ASUS P5B motherboard, with a set of relatively good quality headphones plugged in. I picked a Beastie Boys track (Intergalactic), which has a good mix of smaller background sounds, some bass, and a good mix of vocals. I ran it first through the onboard sound to my headphones, then changed the input to the USB DAC, and played again, same volume, same headphones.
The quality of each was on a par to my ears, in this test I could not really tell a difference between the two. I think I could hear the treble end of the spectrum a little more clearly on the USB DAC than the onboard.
So, it passes test 1. Its no worse than a good desktop onboard sound.
Test 2. Time to just buck up, and throw it into the car. the motherboard is buried inside my centre console, so its not easy to access. The amp is under the front passenger seat, very easy to access. There is a powered 7 port USB hub in my centre storage bin, very easy to access.
So, i connected the USB DAC from one of the ports on the 7 port powered hub, ran it on its supplied USB cable down to under the seat, and used a pair of 6 inch RCA Y splitters to connect it to my 4 channel amp (The old setup had the splitters already, I was using the amp to control fader front to rear).
Rebooted the machine (Windows 7, it installs the drivers, but requires a reboot to finish configuration), sound comes up....and blows my bl**dy ears out...because it was a new device, it sets itself to 100% volume
Dropped the volume down, and straight away, I could hear an improvement over the Intel D945GCLF2 onboard sound.
All of the background hiss was gone, I believe because the analogue audio was uncoupled from the main computer, the analogue stage was now 2 feet away from the motherboard due to the USB taking the signal out to the DAC.
Sound was clearer, I could hear the finer details of the music. Things I hadn't heard, like a backing guitar in a track, or a lower bass guitar riff.
The testing in my car was done under Centrafuse 3.1 on Windows 7 32 bit.
I tested standby, and that worked flawlessly, no popping on resume, no missing audio. I will be testing resume from hibernate overnight tonight, and if I get any problems, I will update this thread to let you all know. I will also test the radio side of playback tomorrow, as that is a bit of a weak point of my install (Radio sounds flat and lifeless, but I believe that is partly interference issues from my M4, I have passthrough caps on order to fix that, thanks to Mickz's suggestions).
So, while I knew that I couldn't possibly provide an audiophile review, I wanted to share this with you guys. It does contain a lot of personal interpretation, and for that I apologise.
What I wanted to provide you all with, is a little comparison of my onboard audio versus a low end USB DAC. I think that spending more on a higher end DAC would allow for things like compressed audio etc, however for me, all I am doing is outputting normal, stereo sound.
I will probably update to something a little better, for instance, I have my eyes out on 2k1Toaster's USB amp that is in prototyping. But for now, I believe I have picked up a good upgrade on the stock onboard audio, at a reasonable price.
So, questions? My flame retardant suit is in the cupboard, should I put it on?
Great writeup. I think you are a little modest about this being a "non-audiophile" review. I too have wondered whether these inexpensive DACs are worthwhile. I now think I'm going to try one myself!
i would count this as a audiophile comment
Originally Posted by Chester
but great detailed review!!
Thanks for the feedback guys
Well, one little update to add to this, I said I was going to test the resume from hibernate with this DAC.
Aaaannnddd... I nearly ended up single. The wife and I jumped into the car this morning, computer resumed from hibernate, and for approximately 1 second, the sound on the DAC resets to 100%, before dropping back to the 15% it was set at last night when I stopped the car.
White zombie, at 6:30am, at an ear splitting volume....The wife is a little upset at me right now. Its going to cost me more in roses than the sound card cost! hahaha
Oh well, its something to add to the todo list:
1) Protect marriage, fix volume reset issue.
2) EVERYTHING ELSE
I'm not sure if this is an issue with Centrafuse, or the DAC, I will have a play around and see what the go is!
Chester, have you had any more problems with this DAC, and have you solved the volume issue? Some people have reported issues with USB soundcards, and changing the delay on resume to 5 seconds seems to fix them.
I get some popping when the system boots, which for me isn't really a problem, they are only small pops as the chip initialises, no heavy thumping.
The sound coming on at 100% was only the once that I have found, it hasn't repeated again, I'm still not sure what caused it that one time, it could have been that it was the first time since it had been fully resumed from hibernation since the card was installed, but im not sure.
One other positive that I have found of this unit over my onboard sound, is that the sound levels are more consistant too. On the onboard sound, the start of a song would come on loud, during the point where it is usually only one instrument starting to play. Then once all the other instruments start up, and the sound becomes more complex, the audio level drops. I assume this is because the onboard audio can't put out enough voltage to keep the sound at the same volume.
Otherwise, from my perspective, this has worked well!
Thanks for the update on this. I just bought one to replace my super cheap USB sound card. I was actually leaning towards buying a NuForce uDAC-2, but this is half as much and it sounds like it will work for me.
And the way I look at it, even if it doesn't work, its not such a huge expense that you have a mild breakdown in the corner of the garage
I looked at it and went "Meh, if it doesn't work, ill just save a bit more for a high end one, no biggie"
Thanks for the review, now if more people will realize that a USB DAC is the way to go for relatively low cost, high quality sound.
The thought never crossed my mind until Chester posted his review. Once I get mine installed I'll post a follow-up to share my thoughts about it.
Originally Posted by Caelric