[Minge]

I have never had a dedicated headphone system until now and I need signal path and decoding clarifications. I have always had a high end system with a pre-amp processor so I have always had my bluray and other components hooked up to a processor via HDMI and had them bitstream the signal to a preamp processor so in this senerio the preamp is doing two things processing the bitstream in whatever format the disc is stereo, dolby atmos, whatever the case may be and also doing the digital to analog conversion. Is this correct or are the two functions the same thing when feeding a bitstream signal?

The reason I ask is now I am setting up a dedicated headphone set-up with an audio gd headphone dac/amp that has both digital and analog inputs. The audio gd has an HDMI input but without the benefit of a processor in the chain what signal would I feed the headphone dac/amp when using a digital input like the hdmi or toslink? would I or should I still bitstream the signal to the headphone dac/amp? My bluray player the Oppo 105D has two HDMI outs so leaving the player to bitstream all the time while using either my conventional theater system or while listening with my headphones is preferred but I am not sure what is the best or may be the only way to feed a signal to my headphones set-up as I do not know if a bitstream needs further processing that my headphone dac/amp is not capable of? Also the headphone DAC is of high quality so a digital signal to the headphone set-up I believe would be the way to go as it is more then likely superior to the dac in the Oppo player.

I need some help in explaining the signal and processing paths please as I am just not that technical in this regard.

Thanks for the help...

 

[castleofargh]

you have a few vocabulary problems here. first a pre-amp is a pre amplifier, it takes analog signal and outputs analog signal with a different gain. nothing more. only a DAC(digital to analog converter) can turn a digital signal into an analog one.
a DAC typically "speaks" only one digital format, usually that would be some version of PCM, or DSD(sometimes both). chances are it is limited to stereo input and output for headphone gears.
so anything different will have to be converted/decoded before reaching the DAC(so before the Audio GD if you want to use the DAC in it). be it some surround to headphone processing, or converting some specific digital format into what the DAC can interpret, all that will be done and set on the Oppo 105D.
now for the specifics, it will mostly depend on what you want to do and what the Oppo offers on each specific output. for example, it it certain that it offers to downmix multichannel sound to stereo on its own headphone out, but you'll have to RFTM to know if it also offers that option on a digital output compatible with the Audio GD. the Oppo 105D has plenty of outputs so I have little doubt that you'll find a way to get what you want. just looking at the specs it looks like a really cool toy. ^_^

 

[71 dB]

.., but you'll have to RTFM to know...

Why read manuals when asking online is easier? Well, it's not nice to make other people "work" for you. Asking online is totally ok and a big reason for why online boards exist in the first place, but it is nice if you read the manuals yourself first and then if you still have questions because the manual was so badly written, go to a forum with your specific question such as "The manual says this: Blah blah. Does it means this?" etc.

 

[bfreedma]

The Oppo xx5 series players have upgraded audio components, including the DAC, so you might consider letting it do the decoding and connecting to your headphone system via analog cables (it supports RCA and XLR).

If you want to let your AudioGD do the decoding/converting, you could use either HDMI or Coax. If you use HDMI, the HDMI AUDIO setting should work on "Auto" as it will attempt to handshake with the destination device and determine what type of digital audio format is supported. If that doesn't work, it's probably best to set it for "LPCM" to avoid having to worry about the type of bitstream being sent and whether the AudioGD can decode it.

Page 63 of the Oppo manual has the info you're looking for.

 

[bigshot]

I have an Oppo player and it sounds the same to me as running HDMI into my Yamaha AVR.

 

[bfreedma]

I have an Oppo player and it sounds the same to me as running HDMI into my Yamaha AVR.

I do as well. I think the question is more around connectivity options and associated device setup than sound.

Wish they hadn’t left the market. Oppo made quality hardware and was always fast with firmware updates as new BR disc security issues arose.

 

[castleofargh]

Why read manuals when asking online is easier? Well, it's not nice to make other people "work" for you. Asking online is totally ok and a big reason for why online boards exist in the first place, but it is nice if you read the manuals yourself first and then if you still have questions because the manual was so badly written, go to a forum with your specific question such as "The manual says this: Blah blah. Does it means this?" etc.

TBH, my lovely mother is one of those people who would rather not use a device than have to read a manual. I can't say that I understand her in that respect because I really don't, but at least I know for a fact that there are such people. it's not simple laziness, for her it's a life principle. don't waste food, help people in need, do not read operating manuals. ^_^

 

[Minge]

Why read manuals when asking online is easier? Well, it's not nice to make other people "work" for you. Asking online is totally ok and a big reason for why online boards exist in the first place, but it is nice if you read the manuals yourself first and then if you still have questions because the manual was so badly written, go to a forum with your specific question such as "The manual says this: Blah blah. Does it means this?" etc.

TBH, my lovely mother is one of those people who would rather not use a device than have to read a manual. I can't say that I understand her in that respect because I really don't, but at least I know for a fact that there are such people. it's not simple laziness, for her it's have a life principle. don't waste food, help people in need, do not read operating manuals. ^_^

Wow...I am sorry if I have offended and I was simply looking for conductivity and conversion of signal/clarifications. The Audio gd products are made in china and the user also called a "use" manual is clearly written by folks who don't speak the language. A written manual is not included with the product. The "use" manual is online I have helped countless people on other forums even if I felt the questions were straight forward without calling them out. I am not lazy and I can read, I was just confused as what a typical dac in a headphone setup with an HDMI can or cant do to decode certain signals. Again, sorry, to those who answered what may have been a poorly worded question, I thank you very much. I was not my intention to have you do the work for me as suggested by others.

 

[71 dB]

Wow...I am sorry if I have offended and I was simply looking for conductivity and conversion of signal/clarifications. The Audio gd products are made in china and the user also called a "use" manual is clearly written by folks who don't speak the language. A written manual is not included with the product. The "use" manual is online I have helped countless people on other forums even if I felt the questions were straight forward without calling them out. I am not lazy and I can read, I was just confused as what a typical dac in a headphone setup with an HDMI can or cant do to decode certain signals. Again, sorry, to those who answered what may have been a poorly worded question, I thank you very much. I was not my intention to have you do the work for me as suggested by others.

No problem. Hopefully you have got answer that help. It's true sometimes manuals are bad. My Sony TV has "rubbish" manual: Most of it is about how you install the unit on the wall (useless information for me, because I didn't install it on the wall) and minimally about the functionality. I have improved the manual myself by handwriting information that I have gathered over the years. I do read manuals carefully, because I want the best out of the devices I spent my hard earned money on.

My Cambridge Audio Blu-ray player can be output analog 2.0 from multichannel sources and I like Lt/Rt downmixing. Works nicely with crossfeed+headphones.

 

[bigshot]

I think the answer is to plug your headphones into the headphone jack of the Oppo and see if that works. Bet it does.

 

[bfreedma]

I think the answer is to plug your headphones into the headphone jack of the Oppo and see if that works. Bet it does.

It should power many headphones adequately, but it isn’t the highest output amp. Certainly worth a shot.

600 Ohms - 17mw
300 Ohms - 34mw
150 Ohms - 63mw
120 Ohms - 77mw
60 Ohms - 120mw
30 Ohms - 187mw

No harm in discussing the mechanics of plugging into the AudioGD as requested, is there?

@Minge - what headphones are you using and what’s the model number of the AudioGD?

 

[Minge]

I think the answer is to plug your headphones into the headphone jack of the Oppo and see if that works. Bet it does.

Sadly, this is the main reason I purchased the Oppo105D was for its headphone amp section and I found it to be not very dynamic at all with my Grado RS1's. Hence the reason I purchased the the Audio gd headphone DAC amp. I want to use the digital inputs on the headphone amp paired with my Oppo player as I want to use the analog inputs for my music streaming box the Bel Canto eone stream.

 

[bigshot]

The DAC isn't the problem... the amping probably is. Just get an inexpensive headphone amp. That will probably fix your problem for under $100.

Edit: Just checked the impedance of your cans. They should be fine right out of the Oppo's headphone jack. I'd suggest you do a line level matched, direct A/B switched blind comparison between the headphone out of your Oppo and whatever DAC you think will solve the problem. All you need is a headphone switch box that costs about $20. I bet you'll find that the differences don't exist and it was just inconsistent levels. If there is a difference, your Oppo is probably defective (which isn't terribly likely).

You could also use the switch box to switch analog inputs after you're done with the test, so you wouldn't need to use the digital inputs. All of this stuff should be audibly transparent. It doesn't really matter how you plug in.