A simple DAC question I just can't wrap my small brain around. Help, please?

[JayWoodall2]

Lets say I am using a computer as my digital source. And I have a USB cable from computer into a DAC, then into my amp to my speakers. As the signal originates in the computer, it flow through the computer's sound card and on board DAC before it flows out the USB cable. So that once the signal reaches the external DAC via the USB it has already been converted from analog to digital inside the computer, right? So what benefit is the external DAC?

In other words, if you have a DAC "downstream" from a computer that has its own DAC (however bad it may be), then how does the external, downstream DAC provide any benefit? Does it somehow "communicate upstream" to the computer that the computer should not use its own DAC, but to use the external one (of allegedly better quality).

I hope this question makes sense. And I appreciate (in advance) you being gentle with this digital virgin for my "first time", for- yes- I am as ignorant as my question implies. Thanks, JW-

 

[ldatlof]

The USB bypasses the computer's internal DAC.

 

[Poinzy]

What Idatlof said.

 

[SoNic67]

I don't think that bypass is the right word. That would imply that somehow both the input and output of the onboard DAC and USB are connected.

USB is just a way to send the digital audio signal from inside the PC to the external DAC. So it's not at any point analog signal or connected to the internal DAC output. Or even the input...

 

[vonclod]

Only if you used the headphone jack you you be getting the analog out from the computer's DAC, usb is digital out.

 

[JayWoodall2]

Excellent! I am getting smarter by the second over here...

Thank you for answering, but you know that no good deed goes unpunished. Some follow ups, please:

1- If USB by-passes the DAC in the computer, can I assume that the headphone jack on the computer does NOT by-pass the DAC?

2- What about the HDMI jack on my computer? has it used internal DAC or by-passed it?

3- If I want to use a CD player as a transport only (with intent of using separate DAC), does that CD player need to have a mechanism to tell it to by-pass the internal DAC?

4- There is a HUGE price disparity between various DAC's. (portable headphone amp/DAC for $30 versus $3-5k +++ home units) Why? Are they based upon different technological principles (like classes of amps) or are they all made based upon the same principle with varying degrees of quality components?

• Where is the "sweet spot"? How much need I spend to get really good performance. (Yes, a totally subjective answer. But most of us still seek some kind of max value for money balance of some sort.)

Sorry to quiz you like this. Yes, I could get off my ass and research some of this myself, but why rob you of the fun of talking about your fun toys and what you have learned. And afterwards, maybe I will let you join Huck and I in the great fun of painting this fence. Thanks, JW-

 

[JayWoodall2]

some of my follow ups were answered already. sorry for redundancy. Thanks All !!!

 

[Alobar]

Some media players are set to go exclusive to the USB DAC such as JRiver and in that mode it completely bypasses the internal sound card I believe. At lesst that is what happens to my system.

 

[SoNic67]

The internal DAC sends signal only to the analog green jack. That's all it does, it is not involved in any transmission or manipulation of digital signal.

"sweet spot"? It depends of your finances mostly. If you have an income of $20k or $100K or $500K it makes a lot of difference of what "sweet spot" is.
Although after a level (IMO around $1000), there are diminishing returns, and you really need to have an educated ear/brain and good recordings material to perceive any benefits.

 

[savatage1973]

If I want to use a CD player as a transport only (with intent of using separate DAC), does that CD player need to have a mechanism to tell it to by-pass the internal DAC?

If you want to use a CDP as a transport only in conjunction with an external DAC, the CDP has to have some kind of digital output (usually coax or optical)--very common on newer (90's and up) units--not so much on older units. This will "bypass" the internal DAC in the CDP and send the "raw" digital signal to your external DAC.

There is a HUGE price disparity between various DAC's. (portable headphone amp/DAC for $30 versus $3-5k +++ home units) Why? Are they based upon different technological principles (like classes of amps) or are they all made based upon the same principle with varying degrees of quality components?

The technological principle is basically the same for all DACs--convert the digital signal (ones and zeros) to an analogue audio signal--however there are different levels of performance related to the specific DAC chipset and then the analogue part of the circuit that brings that "converted" analogue signal up to line level output--so there are different "quality" levels in the analogue stage--like op-amps and/or tube output stages. Basically, the DAC has to incorporate some kind of analogue pre-amp stage to get the desired level of output, and can have a huge influence on the sound characteristic/quality.

Where is the "sweet spot"? How much need I spend to get really good performance. (Yes, a totally subjective answer. But most of us still seek some kind of max value for money balance of some sort.)

Of course, budget is a consideration--what are you comfortable spending on a DAC? Another factor is my "level playing field" theory--if your entire system is uber high-end, then you will probably want to invest in a "high-end" DAC--but if your system is more "mid-fi" (and I hate to use that term, but will for lack of a better term), then you don't need an uber high-end DAC. One single "stellar" component will not make an "average" system sound "stellar", but a single "poor" component can make a "stellar" system sound "average" or "poor". I hope this makes sense--I am struggling with words to get my point across. And then back to where it all starts--the source--if you are feeding your DAC from a computer loaded with/and or streaming low bit-rate digital files, it will only convert and reproduce what it is fed--the old "garbage in = garbage out" proposition.

 

[JayWoodall2]

Ya'll are great. Much thanks, JW-

 

[rwartner]

I am curious about the HDMI part of the question. Is there a sensible way to use HDMI in this configuration? I've googled this a bit but... Without knowing much it would seem that HDMI would be a better output than USB. So then I wonder why my DAC doesn't have HDMI input.

 

[rocknroll1]

sorry to highjack but this brought up a question for my 2nd system. There is a problem with the digital out on my CDP so I am running it analog out to my DAC (maverick D1) analog in. Is the DAC during anything? Also my streaming runs thru airport express from a 3.5 jack with adopter for a digital coaxial cable into DAC. Same question, is DAC doing anything?

 

[JoeESP9]

When using the analog input on a Maverick D1 the onboard DAC is bypassed.

 

[cratz2]

sorry to highjack but this brought up a question for my 2nd system. There is a problem with the digital out on my CDP so I am running it analog out to my DAC (maverick D1) analog in. Is the DAC during anything? Also my streaming runs thru airport express from a 3.5 jack with adopter for a digital coaxial cable into DAC. Same question, is DAC doing anything?

If you run analog from your CD player to your Maverick, you aren't using the Maverick as a DAC and all of the digital to analog conversion is happening inside your CD player.

In that instance, the Maverick is only acting as a preamp and a headphone amp and you are not utilizing it as a DAC at all.

 

[cratz2]

Another question, if you use a laptop as your source and you run an HDMI directly to the TV, can you run a USB to a USB DAC? Since HDMI conveys audio, will you technucally be sending ditital audio to the TV (which you can turn down of course) AND digital signal to the DAC?

 

[2broke4this]

Another question, if you use a laptop as your source and you run an HDMI directly to the TV, can you run a USB to a USB DAC? Since HDMI conveys audio, will you technucally be sending ditital audio to the TV (which you can turn down of course) AND digital signal to the DAC?

Unless somebody on here knows something I don't (totally possible), Windows won't let you use the two simultaneously. You can certainly have them both hooked up, but you'll have to switch the outputs back and forth in the sound settings. For example, I've got a computer in my living room that's connected to the TV over HDMI... and we usually just use that (the TV is connected to a soundbar that sounds better than you'd imagine)... but it's also connected to a little Aune DAC over USB, which is connected to the stereo. I can go into the sound settings and switch to the Aune when I want to play something from the computer on the stereo instead of through the TV and soundbar. I think I've done that exactly once, but knowing that I CAN is fun.

 

[SoNic67]

Windows does not output simultaneous to two soundcards (both HDMI and USB will be present as audio devices).

Some TV's have a digital audio output that will repeat out what is present on the HDMI input, in certain conditions.

 

[ferninando]

usb question.
what usb port do you get the audio . ?
the sound card?
or somewhere else.
just any available usb port?
Thanks for helping a usb dummy.

 

[SoNic67]

Any USB port, same like the mouse, keyboard, memory stick or anything else on USB.