Brief Odac impressions - Page 85

 

 

It is not.

Can anyone comment on the ODAC that has used the Alien DAC v1.1 before?  I'm considering upgrading, but would like to know their relative performance pros/cons.  

Thanks for the info. Apparently people don't think it makes that big a deal since they're rating it higher than dacs that do have asynchronous.

I think in one of the original blog posts about the odac he describes why it doesn't need to be asynchronous. I think he may go into depth as to why it isn't super important

Basically, the argument against asynchronous USB is that it is not required for reducing jitter to inaudible levels, and chips that support it would currently require proprietary drivers on Windows (in addition to there being fewer choices at higher prices, and more restrictive licensing).

No its not asynchronous....

 

Alex

I have an odac/amp unit and was wondering if the amplification of the amp will distort external speakers. Basically is there a volume setting or switch on the device that bypasses the internal amp? Or do I have to just buy an odac by itself for that purpose? I have the headphone out connected to a pair of audio engine 5's and the odac/amp sounds like crap. This is connected to powered USB hub running foobar in wasapi mode.

The O2 does not really distort the sound in an audible way if you set the gain and volume correctly for using it as a line buffer. Ideally, you would want 1x gain and maximum volume. If you do not have 1x gain, and do not need 6.5x (it normally should not be used with the ODAC, unless you control the volume on the PC), then it is possible to turn the 6.5x gain mode into 1x by clipping two resistors. With the default 2.5x gain, you may need to reduce the volume so that the output voltage of the O2 does not cause clipping in the input stage of your speaker amplifier.

Just to be clear, that includes using a subtractive EQ, Replaygain, and generally any DSP that reduces volume.

I meant that setting the 6.5x gain with the ODAC requires lowering the volume on the PC, because otherwise the 6.5 * 2 = 13 Vrms full scale voltage will cause the gain stage of the O2 to clip. But using the high gain normally only makes sense to get the last few dB of power out of very hard to drive headphones, or if the digital signal played is very quiet and never gets even close to 0 dBFS.

It's not async

 

I don't think you'll hear much of a difference given your headphones, to be honest. Even with more resolving headphones.. You probably wouldn't hear much of a difference, but if you want to upgrade, go for it.

R19 and R23 are the resistors you clip to drop the gain :)

mnarwold...

 

I have the HRT MSii and HRT MSii + and the ODAC.

 

Comparing them they all sound very good....it would be hard to tell them apart...

 

Alex

Thanks for the info. I'm taking the leap and selling my head streamer and getting the ODAC and probably the O2, but I'm not totally decided on the amp yet. I wish it were dual voltage. I'll have to pay a little extra and get a power converter since I do a lot of traveling.

Fyi...

 

The only real difference that I have noticed is the HRT USB dacs have a higher output voltage...ie some say this is running 'hotter' so when you do a compairison

it seems like there is a difference but if you level match the volumes the differences dissappear...I wish I had a dime for the number of times I have gone back and forth between

these dacs.....they all are really good....and then when you consider the price...its almost a no brainer....

 

Good luck in your choice!

 

Alex