wvu80 Posted May 18, 2015 Share Posted May 18, 2015 (edited) I maybe way off base here but I would ask BEC (or Dean) if its OK to run your speakers with the tweeter disconnected. Unless of course you have a dummy load hooked up. Hmmm. Eminently practical. I've run my 2-ways in bi-amp mode sometimes with either HF or LF disconnected (to see if it would blow up ) and did not have any problems, but of course, I didn't push it. But this is a 3-way and your point is well taken! Edited May 18, 2015 by wvu80 Quote Link to comment Share on other sites More sharing options...
Schu Posted May 18, 2015 Author Share Posted May 18, 2015 (edited) I've found the problem to be distortion in the analog amplifiers at line level from DAC output --> downstream-- all analog. The recordings aren't actually bad, it's that some tracks actually wind up saturating the op amp output in these analog circuits, which aren't quite fit for purpose. YMMV. this is something I had suspected as a possibility because when I play the same song via HDMI (no stand alone DAC) it sounds perfect... just not as detailed. My thought initially was that the Oppo was somehow overloading the DAC... but how is that even possible? I have two ESS 9018 dacs, the series in the Wyred DAC2SE(coax) and the one in the Pioneer SC85(HDMI). as a general rule, they are somewhat close in sound quality but the Wyred wins out in really critical listening. Edited May 18, 2015 by Schu Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted May 18, 2015 Share Posted May 18, 2015 https://youtu.be/pbmGoMywAf0 who made the recording - on this, it's Radiohead. ALL their digital recordings seem compressed and overly saturated... like loudness wars on steroids. but I have heard this crackling on other recordings, again always the same recordings. The Vinyl releases they do are wonderful... the LP's are mastered and released in 45rpm's and that is taking extra care for sound quality. i'll play my copy of KP tonight since we have similar speaker setups to see if I notice anything similar. Quote Link to comment Share on other sites More sharing options...
Schu Posted May 18, 2015 Author Share Posted May 18, 2015 TY... Quote Link to comment Share on other sites More sharing options...
Chris A Posted May 18, 2015 Share Posted May 18, 2015 My thought initially was that the Oppo was somehow overloading the DAC... but how is that even possible? Are the discs that are giving you trouble all CDs (i.e., 44.1 kHz PCM)? Quote Link to comment Share on other sites More sharing options...
Schu Posted May 18, 2015 Author Share Posted May 18, 2015 (edited) Yes... all of them. Edited May 18, 2015 by Schu Quote Link to comment Share on other sites More sharing options...
Chris A Posted May 18, 2015 Share Posted May 18, 2015 drat...I"m thinking that it could be conversion from bitstream to some other format upstream of the DAC might cause spurious DAC conversion issues (i.e., clipping). but I'm not aware of this issue elsewhere. Perhaps if there is something that is scaling up (i.e., multiplying) the data words upstream of the DAC, it could cause the DAC to perform strangely. It could also be the analog amplifiers just downstream of the DAC, too. Quote Link to comment Share on other sites More sharing options...
Chris A Posted May 18, 2015 Share Posted May 18, 2015 I found an article that may be relevant, albeit a bit technical in places: http://cdn-downloads.tcelectronic.com/media/1018176/nielsen_lund_2003_overload.pdf Quote Link to comment Share on other sites More sharing options...
Schu Posted May 19, 2015 Author Share Posted May 19, 2015 drat...I"m thinking that it could be conversion from bitstream to some other format upstream of the DAC might cause spurious DAC conversion issues (i.e., clipping). but I'm not aware of this issue elsewhere. Perhaps if there is something that is scaling up (i.e., multiplying) the data words upstream of the DAC, it could cause the DAC to perform strangely. It could also be the analog amplifiers just downstream of the DAC, too. Well, I did have this same idea... meaning it was coming from the dac conversions. Take a look at the two playback set ups and see the two completely different sound output. This has me thinking it is coming from the dac itself during conversion, the signal being clipped at the output of either the oppo or the wyred, or the interconnects themselves. Quote Link to comment Share on other sites More sharing options...
richieb Posted May 19, 2015 Share Posted May 19, 2015 I too experienced an intermittent hissing sound from the tweeter in only my Right KHorn. First thought was a bad driver which checked OK. So I then turn attention to the Alk network. Even went so far to contact Al K for advice. Long story short - it was the CD player! Haven't had it looked at yet but another player was inserted, problem solved. I would have never suspected my trusty player to go down but indeed there lie the problem. Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted May 19, 2015 Share Posted May 19, 2015 unable to replicate in my system. Quote Link to comment Share on other sites More sharing options...
Schu Posted May 19, 2015 Author Share Posted May 19, 2015 unable to replicate in my system. What is your system layout for this playback? Like I had mentioned, it disappears with hdmi. Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted May 19, 2015 Share Posted May 19, 2015 macbook pro > gungnir (usb) > tube amp i guess my point was that it doesn't appear to be the source music, as it relates to Karma Police. Quote Link to comment Share on other sites More sharing options...
Schu Posted May 19, 2015 Author Share Posted May 19, 2015 I see... not "Karma Police" though. "Pulk/pull revolving door" on ok computer. I had confirmed it is not the disc/recording alone because as demonstrated by the two videos, it doesn't happen on the hdmi/pioneer dac playback but does on the coax/wyred dac playback. Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted May 19, 2015 Share Posted May 19, 2015 oh i didn't listen to the video, and I thought I saw you mention Karma Police.. so I gave it a listen and didn't notice anything abnormal. "Pulk/Pull Revolving Doors" is on Amnesiac.. Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted May 19, 2015 Share Posted May 19, 2015 My thought initially was that the Oppo was somehow overloading the DAC... but how is that even possible? Schu, from what I hear on my end between the two videos it sounds like digital clipping. Some gear handles it more gracfully than others. Horns simply pass the buck. Run the song fille through the DR Database off-line analyzer. That'll tell you instantly what's going on. If you don't have the software, you can send me the file and I'll run it through on my end. That file very likely runs over. Quote Link to comment Share on other sites More sharing options...
Chris A Posted May 19, 2015 Share Posted May 19, 2015 (edited) If you've ripped the track(s) of interest to a computer, you could easily do the following to fix them so that they don't create the cracking sound: 1) install and run Audacity (version 2.1) 2) open the offending music track 3) select Effect:Normalize... and set the max level in dialog box to -10 dB 4) select Effect:Clip Fix... at 85%, let it run until completed, notice all the "spikes" that appeared on the plot...(they're not spikes) 5) select Effect:Normalize... and set the max level to -0.3 dB 6) play your declipped track back to verify that there is no clipping. The new track should be at least 10 dB quieter. 7) export the new track to disc--forget the old track... Voilà! Edited May 19, 2015 by Chris A Quote Link to comment Share on other sites More sharing options...
JJkizak Posted May 19, 2015 Share Posted May 19, 2015 I kind of get the same thing from my local digital FM station but it varies from day to day It seems something can't handle the very complex voice consonants especially chorus backups. But then again the next day it's fine. JJK Quote Link to comment Share on other sites More sharing options...
Guest David H Posted May 19, 2015 Share Posted May 19, 2015 (edited) Does the Oppo have an output level control? I have run into this same scenario using a computer, simply had to turn the level down. Edited May 19, 2015 by GotHover Quote Link to comment Share on other sites More sharing options...
wvu80 Posted May 19, 2015 Share Posted May 19, 2015 (edited) If you've ripped the track(s) of interest to a computer, you could easily do the following to fix them so that they don't create the cracking sound: (snip) This may be a workaround but not the solution to the true problem. See Shu's Post 22 where he suspects it is in the analog conversion, since the playback with HDMI sounds perfect (without distortion, anyway). Shu, I suspect your guess is correct. There must be something in the conversion algorithm that is making that recording run "hot." But IF that's true, the next question doesn't become "why" but WHAT can you going to do about it? My answer is you could live with a couple of hot recordings, you could tame the original tracks as Chris suggested, or you might contact Oppo and see what they have to say about it. To truly solve the problem you might have to remove a piece of equipment from your signal chain. Are you willing to live with an occasional hot recording to keep the benefits of your nice equipment? My guess is that you are not the first one to have this distortion problem, and that somebody somewhere has the answer. Edited May 19, 2015 by wvu80 Quote Link to comment Share on other sites More sharing options...
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