Which Audio spec ?
in [Hardware]
|
From: Motor T on 13 Jul 2010 11:57 I'm looking at 2 new mid-tower cases. One has I/O jack that supports AC97 audio and the other supports HD Audio. I'm confused as to which one is most necessary? If it supports one, does it support the other? (I've seen one with the following: 'supports AC97/HD Audio'). Would this be 2 separate connections to the motherboard? I just listen to cd's and mp3's. My granddaughter watches the occasional DVD. Thanks for suggestions.
From: John McGaw on 13 Jul 2010 14:00 On 7/13/2010 11:57 AM, Motor T wrote: > I'm looking at 2 new mid-tower cases. One has I/O jack that supports > AC97 audio and the other supports HD Audio. I'm confused as to which one > is most necessary? If it supports one, does it support the other? (I've > seen one with the following: 'supports AC97/HD Audio'). Would this be 2 > separate connections to the motherboard? I just listen to cd's and > mp3's. My granddaughter watches the occasional DVD. Thanks for suggestions. AC97 is the old Intel header standard. HD is the new Intel header standard. Both are 10-pin connections with 1 key position. http://www.tech-faq.com/high-definition-audio.html It seems that cases with front panel audio connections often have a dual-purpose motherboard connector or two separate connectors so that the case will work with either standard. All three of my recent Antec cases have been like this. From a manual for a recent Antec case: "CONNECTING THE AUDIO PORTS (AC� 97 and HDA) There is an Intel standard 10-pin AC� 97 connector and an Intel 10-pin HDA Definition Audio) connector. You can connect either of them to your motherboard depending on the specification of the motherboard. See instruction below: Note: Please check your motherboard manual for your audio header pin layout make sure it matches the table below. Even if your system supports both audio standards, you may only connect one connector not both."
From: Motor T on 13 Jul 2010 16:56 John McGaw wrote: > On 7/13/2010 11:57 AM, Motor T wrote: >> I'm looking at 2 new mid-tower cases. One has I/O jack that supports >> AC97 audio and the other supports HD Audio. I'm confused as to which one >> is most necessary? If it supports one, does it support the other? (I've >> seen one with the following: 'supports AC97/HD Audio'). Would this be 2 >> separate connections to the motherboard? I just listen to cd's and >> mp3's. My granddaughter watches the occasional DVD. Thanks for >> suggestions. > > AC97 is the old Intel header standard. HD is the new Intel header > standard. Both are 10-pin connections with 1 key position. > > http://www.tech-faq.com/high-definition-audio.html > > It seems that cases with front panel audio connections often have a > dual-purpose motherboard connector or two separate connectors so that > the case will work with either standard. All three of my recent Antec > cases have been like this. > > From a manual for a recent Antec case: > > "CONNECTING THE AUDIO PORTS (AC� 97 and HDA) > There is an Intel standard 10-pin AC� 97 connector and an Intel 10-pin > HDA Definition Audio) connector. You can connect either of them to your > motherboard depending on the specification of the motherboard. See > instruction below: > > Note: Please check your motherboard manual for your audio header pin > layout make sure it matches the table below. Even if your system > supports both audio standards, you may only connect one connector not > both." > Thanks John, Very interesting reading..... I like the thought of having the PC detect which port I plugged into and configuring the port to support the device. (What will they think of next??). I guess I'll go with the newer standard HD. As an aside, I like the Antecs but I'm afraid the features I want (front e-sata port) are not available on their cases that are the size I'm limited to. Thanks again.
From: Paul on 13 Jul 2010 18:44 Motor T wrote: > I'm looking at 2 new mid-tower cases. One has I/O jack that supports > AC97 audio and the other supports HD Audio. I'm confused as to which one > is most necessary? If it supports one, does it support the other? (I've > seen one with the following: 'supports AC97/HD Audio'). Would this be 2 > separate connections to the motherboard? I just listen to cd's and > mp3's. My granddaughter watches the occasional DVD. Thanks for suggestions. The answer to your question would be, the HDAudio defined tower, will support any new motherboard, but would not be as convenient for a ten year old motherboard. The tower with AC'97 will work with older motherboards or new ones, at least as long as the industry continues to support dual mode operation of the FP_AUDIO header on the motherboard. All my cases here are wired AC'97, and I do have a few HDAudio motherboards with dual mode front panel wiring operation. And I haven't seen a rush to doing HDAudio wiring only, at least when people ask this particular question. I'd still seeing the motherboards having support for dual mode wiring, and the cases are still mostly AC'97 wired. It really should not matter which you use. If you have no interest in putting ancient motherboards in that tower, then the HDAudio tower should be fine. While the other one could be used for either purpose, old or new. Some cases come with two cable assemblies, and you can use the one most appropriate for your motherboard (HDAudio cable assembly for modern boards, AC'97 assembly for older ones.) All they're doing in that case, is disconnecting a few wires from the AC'97 cable. ******* An older motherboard, had an AC'97 pinout which would work with your AC'97 case wiring. Newer HDAudio motherboards may support both AC'97 and HDAudio *wiring* for the front panel, but the trick there is, the AC'97 pinout definition is "simplified", such that it is a subset of the HDAudio pins. In other words, the AC'97 wiring on an HDAudio CODEC equipped motherboard, isn't the same exactly as the AC'97 wiring on an older motherboard. That is how they arrange them to share the same pins. The end result is, the majority of computer cases support AC'97 wiring (full or reduced definition). If you have a "solid block" 2x5 cable assembly, rather than individual wire plugs, then pulling some of the wires out of the solid block, to meet the comments in the middle column below, is recommended. The individual wires scheme is more flexible - you don't hook up the wires you don't need. There hasn't been a complete switchover to pure HDAudio wiring. In part, this was caused by the need for jacks with isolated side contacts, and I didn't see any of those when I went shopping for some. They didn't seem to be distributing them. I view that as a "chicken versus egg" situation, where the case manufacturers didn't want to make any mistakes. In terms of giving pinouts, I'm missing one of the documents I've used in the past, and since the document was just a number, my odds of finding it again are just about zero. In any case, these examples are to illustrate the differences, if any. Traditional AC'97 Modified AC'97 HDAudio ----------------- (for dual mode) (dual mode or otherwise) MIC2 AGND MIC2 AGND Port1_L AGND MICBIAS +5VA MICBIAS ??? Port1_R PRESENCE# FPOUT_R RET_R FPOUT_R --- Port2_R SENSE1_RETURN HP_ON ??? Sense_Send FPOUT_L RET_L FPOUT_R --- Port2_L SENSE2_RETURN (When not used, had (No jumpers needed (Port names reflect the retaskable two jumper plugs, to on header. No return nature of the jacks. PRESENCE# join FPOUT to RET. signals are needed. signal is grounded, if a real HP_ON and +5VA were Power removed for HDAudio cable assembly is being for an optional non-existent headphone connected.) headphone amplifier.) amplfier. Only five wires should really be connected, for fault free performance! Leave the return wires dangling.) The "sense scheme" for HDAudio is shown on page 172 here. ftp://download.intel.com/standards/hdaudio/pdf/HDAudio_03.pdf The modern front panel audio wiring options are shown here. Page 20 and Page 23. Page 20 is a form of modified AC'97, but I wouldn't build a motherboard using that diagram verbatim. Since Sense_Send shares the pin, you wouldn't tie a hard +5V to that pin for example. I don't know what Intel was thinking, when they did page 20. In any case, you can see the inspiration provided by page 20, reflected in the middle column above. http://www.formfactors.org/developer/specs/A2928604-005.pdf The older pure AC'97 pinout is shown on page 20 here for reference. (This defines the older, leftmost column above.) http://web.archive.org/web/20040407073715/http://www.formfactors.org/developer/specs/fpio_design_guideline.pdf The three sense pins on the HDAudio are wired in the computer case, to the two isolated side-contact switches on the headphone and microphone jacks. They would look like this. The front panel wiring assembly contributes the two switches to this picture, while the resistors used to encode things are on the motherboard itself. / +--/ x--+ --------------------+ | | | | X---- resistor --- GND CODEC Sense_Pin ------+-----X chip | | | X---- resistor --- GND --------------------+ | | | | +--\ x--+ | \ | v To two other jack detection circuits on the motherboard The front 1/8" stereo jacks have three contacts. The function and wiring are summarized in this table. TIP RING SLEEVE Headphone LEFT RIGHT GND Microphone (mono) MIC MICBIAS GND (MICBIAS is weak power for electrets, and will not harm other things.) Microphone (stereo) MIC_L MIC_R GND (Separate bias is connected to both channels, to power stereo electrets, and will not harm other things. Example. Andrea Superbeam.) http://www.andreaelectronics.com/Buy/ProductDesc/Superbeam_Array.htm HTH, Paul
|
Pages: 1 Prev: Question about Intel Pentium XE 820 Next: keyboard doesn't work, then does |