[stump4545]

thinking about connecting an external dac to my cable box in my 2 channel HT/ music rig.

you think its a waste or is there audio quality to be gained by hooking up an external dac w/ digital coax connection to watch hdtv, sports, even news?

[turkey]

thinking about connecting an external dac to my cable box in my 2 channel HT/ music rig.

you think its a waste or is there audio quality to be gained by hooking up an external dac w/ digital coax connection to watch hdtv, sports, even news?

If you have a spare DAC or can borrow one, I suppose it's worth trying. I kind of doubt you'll see any benefit from it though. The cable TV companies don't really care about audio quality from what I've seen.

[stump4545]

no benefit you think, not even on prime time network hd programming?

[rollo]

I tried it but for some reason it would NOT work. Unless I did something wrong, I connected the DAC off the cable box to the aux in on the  preamp and no sound.


charles

[WGH]

What type of compression is the cable company using? If you get can get 5.1 sound then you will need a DAC that does AC3 Dolby Digital or DTS like a surround sound processor even for just stereo.

[Nuance]

I'd say don't bother.  The cable/satellite companies compress the audio (and video) too much, so what's the point?  Now if it was lossless... 

[Acoquiner]

New to the forum, sorry if this information is well known to everyone, but Nuance says that cable audio is so compressed that passage through a DAC is not helpful. Is that true for all stations/cable operators? What about FM radio via cable?

Thanks for the info,

Acoquiner

[golfugh]

I used a Cullen mod'd Digital Link III through a Candela tube pre with my HD cable box and it was MUCH better sounding (2 channel only) YMMV.  I have neither the pre or DAC now and send the digital out to an AVP-17.

[srb]

If you get can get 5.1 sound then you will need a DAC that does AC3 Dolby Digital or DTS like a surround sound processor even for just stereo.

Exactly.
 
If an HD broadcast is in Dolby Digital or DTS, there is normally no option to choose a standard 2 channel digital output.
 
I don't know of any audiophile DACs that can accept these formats, so you will either get no sound, or more likely (at least with my 2 DACs), get a horrible loud digital bitsream noise.  I tried it with several DACs, and while it sounded pretty good on non-HD material, when the program switched to HD, it sent me running for the mute to prevent speaker damage.
 
Steve

[golfugh]

You can get 2-channel PCM from a cable box digital out (SA 8300HD), if...you leave HDMI audio on (HDMI direct to display and muted at the display).  The digital out is then straight PCM and not dolby digital.  I've done it and that's how it ran through the Digital Link III.

[Acoquiner]

I agree with golfugh. I have no problem selecting PCM rather than Dolby output on my Sagem cablebox and sending the signal to my stereo system with RCA cables, so 2 channel output is certainly available. My question is whether it is worthwhile to buy a DAC (for example a Musical Fidelity V-DAC) connected to the S/PDIF connector from the cablebox. It seems certain that this DAC is better than the DAC (unknown manufacturer) in the cablebox, but if the original signal is severely compressed as suggested by Nuance, I'm concerned that the benefit may be small.

[Carlman]

Your hunch is correct, Ac.  I have connected my cable box to a DAC and receivers and it really doesn't improve much.. but it does improve.  It's not a 'oh wow, I wish I'd done that sooner' type of change.. more of a 'ah, that's a little quieter background and cleaner sound' type of change.
It still sounds compressed but cleaner overall.

[Nuance]

Acoquiner,

I have something to report...  A friend of mine was watching that Palladia music channel and wondered why it didn't sound the greatest (his system is not at fault, trust me).  He then decided to run the coax out from his DirecTV box through his DAC to his preamp.  This obviously took the center channel and subwoofer out of the mix, but he said the difference was incredible, with the DirecTV feed now sounding like a good Redbook CD.  I am also going to try this, as I have the same DirecTV box, and I'll report back.  Just thought you'd like to know the difference was drastic (in a good way) for my buddy. 

[Acoquiner]

Nuance, I'm sure that this is discussed extensively in one or more forums, but it seems that almost any reported change in equipment results in an improvement in sound quality. This may be something like the "subject-expectation effect" in psychology: the individual who has bought a new whatever expects a benefit and, in the case of the typical audiophile who participates in this kind of forum, hears that improvement and spreads the news. This generates the same kind of expectancy effect in those who read the post. Let's imagine an experiment in which 100 people receive Dac X with the included wall-wart and 100 receive it with a good quality regulated power supply. Now, let's swap power supplies for half of each group, telling everyone that their power supply is being changed for one that has a good chance of improving the sound. Don't tell anyone which group they are in. If people can be completely ojective, 50% of them, not having had any change from the initial power supply, should report "no change", while 25% go to the regulated DAC and should report improvement and the other 25% go from the regulated DAC to the wall-wart and should or may be able to hear the deterioration. If such an experiment could actually be performed, what do you think the result would be?

[Nuance]

Acoquiner,

In this case the DAC was already owned (for many months), and my friend wasn't expecting any change at all.  This is quite different than comparing power supplies, which is a completely different topic that I won't jump into in this thread (most people already know where I stand concerning those).  My pal heard a difference, and that's all I need to know.  If I try it and hear a difference I will report back, but I don't expect people to blindly follow my advice/opinion.  That would be foolish.  Also, whether that audible change really exists or its just cognitive dissonance, I couldn't tell ya.  But if it makes someone happier then who cares?

By the way, you're preaching to the choir man.  If the signal is garbage coming in, I don't expect a huge benefit.  But hey, if there is, I am cool with that. 

[Acoquiner]

Nuance, thanks, sorry to go off topic. Ive just switched from a Creek T43 tuner to a Sagem cablebox into my Audiomat Arpege (speakers are Dynaudio Focus 140s). There is no doubt that my FM reception is more consistently clear, but also the music is less exciting than that from a tuner broadcast under excellent conditions. I have the intention to buy a MF V-Dac to try to improve the sound; whether or not there is an objective difference, if it sounds better to me I'll be happy. If this is the case off course, my next step will be to upgrade the power supply in the V-Dac...

[indiesound]

I wouldn't say it's a waste at all. I use a DAC (HDMI to the plasma TV, optical out to the DAC) (make sure to use a decent HDMI cable in this case, makes a big difference). Comes out perfectly 2 channel for all stations. Listen to the music stations occasionally, they sound good, but obviously not as good as redbook or hires. Movies, TV and commercials sound great. Details in shows/movies like closing of doors, shoes walking, ocean waves sound great. Palladia sounds great. Any show/movie with even anything of a soundtrack is vastly improved. decays are longer,better. I simply don't understand WHY you wouldn't do this.