[Phishin Phool]

Currently most of my headphone use has been with my AVR ( Onkyo TX-NR905) which has Burr-Brown 192 kHz/24-Bit Stereo DACs (PCM1796). I have a tube amp on the way I plan on using but it does not have a built in dac so what I was considering was using the dac in my AVR and then using the analog pre-outs to the analog inputs on the tube amp (Project Sunrise II built by Jeremy from garage1217). If it matters my headphone stable in order of use is Beyerdynamic DT990 250ohm, Pioneer SE-A1000 45 ohm, AT-M50 32ohm.
 
If an external dac would be of any significant benefit what price range would I need to be looking at?
 
For portable use I use either the m50's or Skullcandy Aviators and occasionally Sennheiser HD200's
As always many thanks to those who respond

 

[PurpleAngel]

What source(s) feed in to Onkyo?
 
Might want to ask here about the best way to hook a external headphone amplifier up to the Onkyo TX-NR905.
http://www.avsforum.com/t/884772/the-official-onkyo-tx-nr905-thread

 

[Phishin Phool]

Normally I use my Sony BD-P S550 as my disc player (as much of my listening is on blu-ray ) but also my HTPC fed via HDMI as well as my WD NAS so much lossless flac files (to include 24/192 files), a few .wav files and a few high bitrate mp3. I also sometimes stream from a buddys HTPC via VPN as I have a 24mbps internet connection.
 
In the future there is a good likelihood of adding an oppo bd player to replace the sony. I have kept the Sony because I have been relatively happy with it and it has 7.1 analog outputs which actually have come in handy on several occasions for checking out some older gear.

 

[cel4145]

What source(s) feed in to Onkyo?

Might want to ask here about the best way to hook a external headphone amplifier up to the Onkyo TX-NR905.
http://www.avsforum.com/t/884772/the-official-onkyo-tx-nr905-thread

Definitely ask there in that thread, too. Looks like your Onkyo has pre-outs for front left/right and zone outs, so that would be my guess as the best place to hook up a headphone tube amp. Also has an optical out. It MIGHT be possible to pass a digital signal to it. Ask about those options in that thread.

 

[Phishin Phool]

I know it will work (and how to do it)  but I was wondering if there would be an advantage to using an external DAC - meaning is an external DAC likely to be of better quality than the Burr Brown PCM1796 chip that is inside my avr or at what price range I would be looking at to find comparable sound quality as you can get anything from a $35 china made muse dac all the way up to a $3000+ rotel one.

 

[cel4145]

I know it will work (and how to do it) 

Just make certain it will do what you think it will do. For instance, outputting to the left/right analog outs will probably not downmix a 5.1 audio track from DVD or Blu-Ray. Some zone outputs in some AVRs don't work with digital sources (I have no idea why--lol). Using the analog outputs might also be a little of a pain if you have to go through several menu levels in your AVR to change over to it (I'm betting you might have to select between the analog pre-outs and the speaker output on the AVR).

but I was wondering if there would be an advantage to using an external DAC - meaning is an external DAC likely to be of better quality than the Burr Brown PCM1796 chip that is inside my avr or at what price range I would be looking at to find comparable sound quality as you can get anything from a $35 china made muse dac all the way up to a $3000+ rotel one.

The actual DAC chip makes much less difference than how it is implemented. Some people will claim that an AVR is a very noisy environment that will negatively impact the SQ, but that's a hard general claim to support (I don't see how anyone can know that for every AVR).

That being said, there are certainly going to be better DACs out there, but that doesn't mean the difference will be worthwhile to you. Then your options are more limited on DACs depending on whether or not you want to try to hook up all your sources to it. For instance, I don't know how you find an audio DAC that has HDMI input.

 

[i019791]

  Normally I use my Sony BD-P S550 as my disc player (as much of my listening is on blu-ray ) but also my HTPC fed via HDMI as well as my WD NAS so much lossless flac files (to include 24/192 files), a few .wav files and a few high bitrate mp3. I also sometimes stream from a buddys HTPC via VPN as I have a 24mbps internet connection.
 
In the future there is a good likelihood of adding an oppo bd player to replace the sony. I have kept the Sony because I have been relatively happy with it and it has 7.1 analog outputs which actually have come in handy on several occasions for checking out some older gear.

 
If you get the Oppo BDP-105 in the future, you will also have a very good 2 channel dac plus a headphone amplifier

 

[Phishin Phool]

 Just make certain it will do what you think it will do. For instance, outputting to the left/right analog outs will probably not downmix a 5.1 audio track from DVD or Blu-Ray. Some zone outputs in some AVRs don't work with digital sources (I have no idea why--lol). Using the analog outputs might also be a little of a pain if you have to go through several menu levels in your AVR to change over to it (I'm betting you might have to select between the analog pre-outs and the speaker output on the AVR).
 
Then your options are more limited on DACs depending on whether or not you want to try to hook up all your sources to it. For instance, I don't know how you find an audio DAC that has HDMI input.

Thanks - I know the pre-outs will not down mix but I always make sure in my player to select stereo output from the menu so the AVR is fed 2ch music. Even when listening with my HT paradigm speakers for music I almost always select 2ch unless  some compelling reason not too. I just prefer a 2.0 / 2.1 mix. Also You are correct in that my AVR zone 2 and zone 3 only output on an analog source. All in all I have been very happy with the avr and seeing that it was a flagship model when released at A $2000+ price point it performs very well. The one thing I have to check on is whether the pre-outs and speaker terminals are both active at the same time or switchable and if the pre-outs are variable with the volume control or line level.
 
Eventually I may look at an external DAC for when I use my Tube amp in another room - what I think I will do for now is just use a 'y' headphone to L/R rca converter from my ipod or tablet to the input jacks on my tube amp or just use the L/R rca jacks in one of my other blu-ray players. I have a reading/sitting room that has a small tv with a blu-ray player connected in another room for use when somebody else is using my main theater.
 
Regarding hook-ups all my players have digital coax out which seems to be pretty standard on most external dacs as well as usb inputs for computer use (at least any I would consider)
Thanks for the input.