joethearachnid
Been here a while!
Old head on young shoulders.
Posts: 380
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Post by joethearachnid on Mar 20, 2012 23:52:15 GMT
So here's the deal. I have a FiiO E10 USB DAC that I've had and have been using for a number of months now and I'm pretty happy with it sound-wise. However, I did notice a number of oddities that I meant to check out. Sometimes when I turned my Panda with E10 up to full volume to check noise (no music playing obviously - I'd have neither headphones nor ears otherwise) the DC protection would kick in and the amp would cut off after about 3/4 of the volume knob. Other times it would go happily to full volume (and sound pretty quiet doing it) without cutting out. I figured this had something to do with DC offset but only recently got around to measuring it. My findings from the E10 line out were thus: with music stopped the E10 had <1mV DC offset, <1mv paused in a song with the default DirectSound protocol, <1mV stopped using the WASAPI protocol and ~400mV(!) when paused in the middle of a song using WASAPI. Everything came out negligible with music playing.
Further experimentation shows that the amount of DC when paused varies wildly and changes polarity, so my theory is that the DAC 'stops' the AC wave at a certain point and keeps the voltage at that point, giving a DC offset. It's not exactly a problem to me right now given that I rarely go beyond 1/4 on the Panda volpot and so any DC that gets through is within acceptable levels. It is, however, odd and doesn't happen with other DACs I've tried (haven't tried other computers yet).
Any ideas why this happens?
-JoetheArachnid
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Deleted
Deleted Member
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Post by Deleted on Mar 21, 2012 11:18:19 GMT
Nope but it seems like either a bug in the DAC or software or the PC itself (this problem may not be present with other owners).
Anyway the solution would be to look for updates in Wasapi or DAC. Another 'solution' is to stop using Wasapi Or simply add a capacitor in the input circuit of the Panda.
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joethearachnid
Been here a while!
Old head on young shoulders.
Posts: 380
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Post by joethearachnid on Mar 21, 2012 13:19:01 GMT
Well, like I said it doesn't really cause me any problems, it's just an oddity. I'll try asking FiiO about it.
-JoetheArachnid
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natospec
250+
Squeal like a hawg! Yeeehaw!
when in doubt, the simplest and dirtiest fix will do, even if it is twisted wire and tape
Posts: 384
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Post by natospec on Mar 25, 2012 20:54:32 GMT
Well, like I said it doesn't really cause me any problems, it's just an oddity. I'll try asking FiiO about it. -JoetheArachnid joe, i am having a very similar problem with mine. it may be because of the dac ic itself, being that when running with volume at full the dac does get rather hot (my test was with the casing off {btw, you know that these things have ALPS pots in them? i found that amazing at this price level} and running with music, no headphones, full volume at a starting point of 72 degrees Fahrenheit=ambiant.) after 15 minutes at full volume i checked it using thermometer probes for my fluke meter, and checked every component, the dac chip itself rose to 115.35 -+.01 degrees, while all other components rose to around 92. this seems insignificant, but after that, untill it cools, the audio output is distorted horribly. these dacs seem to not like getting warm or being pushed real hard at all. im almost tempted to change all of the caps to higher quality ones and the headphone jack to a switchcraft 3.5mm that has a tighter grab on the male trs plug. the plug pulling out has been a recurring problem for me
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joethearachnid
Been here a while!
Old head on young shoulders.
Posts: 380
|
Post by joethearachnid on Mar 27, 2012 18:28:50 GMT
I haven't noticed mine getting abnormally hot. Mine has been on for ~9 hours right now and the casing isn't even warm to the touch. I do sometimes have a problem with distortion but unplugging and replugging the USB cable seems to fix that pretty effectively, and the problem occurs pretty rarely. If I used the HPO I'd probably consider fitting a better jack socket, but as it is I tend to use mine almost exclusively as a pure DAC it's not worth it. The standard socket has some serious wobble issues. And yeah, the ALPS pot is impressive. From what I recall all FiiO devices with an analgue volume control use possibly the same ALPS pot, so they may have been bought in massive bulk at some point.
-JoetheArachnid
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natospec
250+
Squeal like a hawg! Yeeehaw!
when in doubt, the simplest and dirtiest fix will do, even if it is twisted wire and tape
Posts: 384
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Post by natospec on Apr 1, 2012 6:22:42 GMT
I haven't noticed mine getting abnormally hot. Mine has been on for ~9 hours right now and the casing isn't even warm to the touch. I do sometimes have a problem with distortion but unplugging and replugging the USB cable seems to fix that pretty effectively, and the problem occurs pretty rarely. If I used the HPO I'd probably consider fitting a better jack socket, but as it is I tend to use mine almost exclusively as a pure DAC it's not worth it. The standard socket has some serious wobble issues. And yeah, the ALPS pot is impressive. From what I recall all FiiO devices with an analgue volume control use possibly the same ALPS pot, so they may have been bought in massive bulk at some point. -JoetheArachnid I think my heat problem may be because im not using it as a dac alone, im using the amp in it as well... i dont have a proper amp at this point.
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