From: nospam@needed.invalid   
      
   On Mon, 7/7/2025 7:38 AM, bad sector wrote:   
      
   >> Here is my summary picture:   
   >>   
   >>     [Picture]   
   >>   
   >>      https://i.postimg.cc/HWJGdpP4/HDAudio-standard-front   
   panel-summary.gif   
   >   
   > Thanks, as usual you come up with the 'expert enough' explanation. But why   
   would Asus do something this stupid? I mean there are times when I might want   
   to hear an overwhelming guitar track in the headphone (remote panel) while   
   ALSO feeding the    
   speakers (board Line-Out) at reduced radiation to let everyone know 'don't   
   fucking bother me!'. Sometimes I wonder where their designers got their   
   diplomas if any (and not  just Asus either).   
      
   It's not on Asus this time.   
      
   The design is an Intel specification. The PDF comes from Intel.   
   Asus just follows it. The purpose of having Intel act as a pseudo   
   PC97 controller, is to make all the hardware companies do things   
   that are compatible with one another.   
      
   For example, HDAudio Codecs were footprint compatible. If you   
   were in the factory, and you ran out of Realtek 48 pin QFP, you   
   could look around and find something that solders in the same spot.   
   And have multi-sourcing.   
      
   In AC'97 days, the Line-Out signal did double-duty. If could   
   drive Line-Out. It could drive Headphones front panel jack.   
   It did not tend to drive both, because the *standard* of the   
   time, steered the output. If you plugged in the Headphone jack,   
   that actually (via switches), disconnected the Line-Out on the   
   back I/O plate. This is why, by default, a new AC'97 motherboard   
   came with two blue jumpers to take the place of the FP cable   
   in the case. It provided continuity so the Line-Out at least   
   worked by default. When you removed the two blue jumpers   
   and plugged in the AC'97 FP cable, then the either-or behavior   
   was in place, and plugging in front HeadPhones, disabled Line-Out.   
      
   When Intel was thinking about the HDAudio era, their initial   
   thought was   
      
      "We will implement this feature in software"   
      
   In other words, when the jack sense detected HeadPhones in the front,   
   the driver would disable Line-Out. That was their initial thought.   
   This got rid of the need for special jacks to mute the Line-Out.   
      
   Then later, someone else said:   
      
      "Wouldn't it be cool if we could drive Line-Out and HeadPhones   
       separately, with no Mute feature implied"   
      
   With an ASIO driver, in principle you could drive separate signals   
   to the two jacks. This would allow, say, driving a set of speakers   
   in the next room, for someone.   
      
   I've not seen a GUI selector or driving software which gets   
   the best out of the hardware. All I can tell you, is the spec   
   sheets started carrying information about how many boost channels   
   (32 ohms) could be operated at the same time. It seems to be   
   an artificial limitation, and more about aligning with the   
   concept of two separate music sessions, than anything else.   
      
   The Zalman 5.1 headphones (three transducers in each ear cup),   
   it really wanted three 32-ohn stereo channels, to drive the   
   transducers. But we never got there, as no HDAudio will   
   drive three of the 32 ohm jack outputs at the same time.   
   Ports without boost, only drive 600 ohm loads and   
   cannot drive "speaker cones" directly (the tiny transducers   
   in the ear cups). Thus the Zalman always needed an external   
   buffer amp, to get enough drive to run all the cones. The   
   hardware industry did not feel obliged to fix that.   
      
      Paul   
      
   --- SoupGate-DOS v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)