RockOn4Klipsch Posted October 7, 2008 Share Posted October 7, 2008 I had a question in regards to DAC's, how do they work and in what applications do they work... for example do DAC's work only in the HDMI, Optical and Coaxial (as these are in my mind digital). Do DACs also work in the older rca cables (red and white). I'm not quite sure I understand. How do analog and digital signals differ in there transfer? and then the decoding/audible response in which we hear. Now I don't mean you have to get down to the electramagnetism that goes on and the transfer to the speakers and get converted to audible sound waves. Quote Link to comment Share on other sites More sharing options...
Guest David H Posted October 8, 2008 Share Posted October 8, 2008 There are many kinds of DAC's for different applications. DAC stands for digital to analog converter, therefore your input signal to the DAC is digital, ie zeros and ones and the digital signal can be delivered through HDMI, USB, FireWire, optical, digital coaxial, etc. The output from an external DAC will offer some type of analog output like RCA XLR etc. A receiver that utilizes and internal DAC will most likely not offer an analog out. Hope this helps. I believe it is fairly accurate, if not, i have not doubt eleventy seven members will correct me. Quote Link to comment Share on other sites More sharing options...
wuzzzer Posted October 8, 2008 Share Posted October 8, 2008 I guess we'll assume you're talking about an outboard or standalone DAC? As GotHover stated, it needs to be fed a digital signal of some sort. Most DACs that I've seen will accept only Toslink (optical) or coaxial digital inputs. I'm sure some might accept HDMI or FireWire but I'd say those would be pretty hard to come by and probably be rather expensive. There are many benefits from an outboard DAC. Some of them are: In very general terms the DACs in an outboard decoder are typically going to be of higher quality than ones integrated into a component such as a cheap or mid-grade CD player. It allows you to use a $20 CD player and have it sound like a million bucks as long as the DAC its connected to is of good quality. Some feel that a cleaner signal path results from having the DAC as a separate unit rather than included with all the other circuits and wiring within the digital device you'd be connecting to it. In order to see if you'd benefit from an outboard DAC you have to look at your components and see if you'd really benefit from one. I'd say most of the time there would be a benefit from one, but if you have great DACs within your CD player then you'd want to use the RCA outputs to your receiver so that you're using the CD player's DACs. If your receiver has higher quality DACs than your CD player, then you'd want to use the CD player's optical or coaxial outputs and let the receiver decode the digital signal. If you feel neither component has that great of a DAC section, then it might be time to look for the outboard DAC. If you look at the back of a DAC it will generally have the optical and coaxial inputs, sometimes only one or two or it may have several. It would then output the audio signal with RCA or sometimes XLR outputs that you would connect to your amplifier, receiver or pre-amplifier. Quote Link to comment Share on other sites More sharing options...
RockOn4Klipsch Posted October 9, 2008 Author Share Posted October 9, 2008 The reason I ask is I have an onkyo tx sr 805 with burr brown DACs and want to make sure that the piece of equipment with the better dacs does the conversion work. How do i get it to the reciever with out the other equipment doing any conversion work. If I send it from the PS3 it sends it as LPCM wich means the PS3 is doing the converting of digital to analog, if i send it via xbox 360, also sends it PCM meaning the xbox is converting it again not the reciever. If i use my cd player PD F407 is already analog (red, white , rca) so it's doing the converting meaning my sources are already sending a converted signal to the reciever and the burr browns DACs are doing nothing. Now maybe I have this all wrong and if i do could someone please explain it to me as I want the burr browns to do the DAC (mostly to see if there's a difference in sould quality). -stefan Quote Link to comment Share on other sites More sharing options...
wuzzzer Posted October 9, 2008 Share Posted October 9, 2008 If you hook up your PS3 with an HDMI cable and select Linear PCM as sound output, the PS3 decodes the surround format but the signal is still sent digitally to the Onkyo. HDMI only sends a digital signal, not analog. I'm not familiar with the XBox as far as if it has an HDMI out option, but if it does that's how you'd want to hook it up. If not, the optical or coaxial output that it probably has would work too. With the PS3 you want to use the Linear PCM sound output and probably with the XBox as well. If you select Bitstream on the PS3 you'll see the message come up that says something about possibly not being able to hear all the sound correctly. If you poke around on http://www.hdmi.org/ you can read more about HDMI's specifications. If you want the best sound quality I would use either your PS3 or your XBox as a CD player if your CD player doesn't have a digital output of any kind. Quote Link to comment Share on other sites More sharing options...
RockOn4Klipsch Posted October 9, 2008 Author Share Posted October 9, 2008 Thanks Mark, that helps, i thought that the PCM was an already converted signal (ie DTS MA and TrueHD come out as MultiCH PCM) then sends it to its respective channel. When I use THE PCM on the PS3 even though its a 2 channel recording it with comes out (flagged) as wither 5.1 or 7.1 depending on the frequency output choosen on the PS3 but will still only play 2ch ( which is only what I want). This is odd as it's flagged as a multich signal and idea about this, not that it's a big deal just don't folllow whats going on. thanks again mark Quote Link to comment Share on other sites More sharing options...
wuzzzer Posted October 9, 2008 Share Posted October 9, 2008 It is converted in a sense, just not converted from digital to analog yet. That's done in the Onkyo. Not sure what you mean as far as the frequency output chosen on the PS3. Are you talking about the section that allows you to change CD output from either 48kHz or 44.1kHz/etc/etc? If so, I have mine set on 48kHz and just use the surround format buttons to choose from stereo, MultiCh, etc. on the Onkyo. Do you have your PS3 hooked up with HDMI or with optical for audio? Have you ran the Audio section's Automatic setup on your PS3? Quote Link to comment Share on other sites More sharing options...
RockOn4Klipsch Posted October 9, 2008 Author Share Posted October 9, 2008 I have my ps3 hooked up with hdmi, and yes in the section about sound out, if it's set a 48kHz it's flagged as being 5.1 and if it's upsampled to the 44.1/88.2/176.4 it's flagged at the reciever as being 7.1. I've ran the automatic sound thing on the PS3 and it all shows up properly (as far as supported channels). Would you put in a CD in your PS3 at the 48kHz setting and press the info button on the onkyo remote and see what it's flagged at. The audio quality is good i was just curious how to get it great, maybe a new cd player's soon to be in the mix. Quote Link to comment Share on other sites More sharing options...
wuzzzer Posted October 9, 2008 Share Posted October 9, 2008 Either I'm blind or I have a different remote than you but I don't see an Info button anywhere on mine. My remote # is RC-690M. Quote Link to comment Share on other sites More sharing options...
RockOn4Klipsch Posted October 9, 2008 Author Share Posted October 9, 2008 on the onkyo remote i believe it says "display" / "Prev Ch", it's the button just below the " ch +" and "ch -. When in the Reciever mode hit that and it will display info about the source signal on the LED display on the reciever. Quote Link to comment Share on other sites More sharing options...
wuzzzer Posted October 9, 2008 Share Posted October 9, 2008 Alright, got it. Mine is the same way, at 48kHz it says 5.1 and at 176.4kHz it says 7.1 Like you said, it does only play in stereo though. The only way you're going to get better sound from a CD is to get one that has better DACs than the Onkyo and that might cost quite a bit. Quote Link to comment Share on other sites More sharing options...
RockOn4Klipsch Posted October 9, 2008 Author Share Posted October 9, 2008 i'm satisfied with them wuzzer, just wasn't sure how it all worked out. Any idea why the CD gets flagged at 5.1 or 7.1 when output in PCM? Like i said before not that it matters but only "why" does it do it. Thanks for all your help and speedy responses wuzzer. Quote Link to comment Share on other sites More sharing options...
wuzzzer Posted October 9, 2008 Share Posted October 9, 2008 I'm not sure why the 5.1 or 7.1 displays and I bought my PS3 used and it didn't come with a manual. I don't think its an incorrect display on the Onkyo but I'm not sure why it displays what it does. Quote Link to comment Share on other sites More sharing options...
sjcruiser Posted October 14, 2008 Share Posted October 14, 2008 You may want to check the PS3's audio output setting under "Settings" submenu of the HDMI out. See attached link section 5 for reference...My guess would be that you have the LPCM 5.1 44.1KHz checked. I don't know how it was implemented, but it may preffer multi-channel against the 2ch if you have all those options checked when playing a redbook cd. Link: http://manuals.playstation.net/document/en/ps3/current/settings/audiooutput.html Quote Link to comment Share on other sites More sharing options...
RockOn4Klipsch Posted October 17, 2008 Author Share Posted October 17, 2008 after doing a little more reading it say that at given xx.x Hz connected via HDMI *MUST* be output Mult Ch PCM so that would explain it in a sense. Quote Link to comment Share on other sites More sharing options...
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