ALC898 audio dropouts on rear jack only

[racerx90]

Thanks for the test results. In your case, there is no explanation for good sound with green front and bad sound with green rear because the same amp/mixer is used for both. For green rear and black rear, different amp/mixers are used. What happens when you connect the headphones to green rear and black rear.

Okay - here's what I've tried (hopefully this table makes sense.) Please note that all the results are based on the sound output from the speakers (not from where the headphones are plugged in.)

headphones location + speakers location = result (sound preferences output device)

green rear + black rear = audio dropouts (line out)
black rear + green rear = audio dropouts (internal speaker)
green front + black rear = no audio dropouts (line out)
not plugged in + green front = no audio dropouts (internal speaker)
not plugged in + black rear = audio dropouts (line out)
not plugged in + green rear = audio dropouts (internal speaker)

Hopefully, that's everything you've asked for. If not, please let me know.

Basically, the two working 100% working configurations are when you always have headphones plugged into the front green audio jack.

 

[racerx90]

Also, is there a way to disable the green rear jack in the driver? Just curious if there's another thing we could try testing here. Thanks!

 

[toleda]

Okay - here's what I've tried (hopefully this table makes sense.) Please note that all the results are based on the sound output from the speakers (not from where the headphones are plugged in.

Thanks, I'm still processing the data. What version is S/L/E/AppleHDA.kext (Finder/File/Get Info)?

 

[racerx90]

AppleHDA.kext is 2.3.1 (it came from Multibeast 5.1.1.)

If there's anything else you need or would like me to try, just let me know and I'll get it for you. Thanks!

(Also, if you like I can record what the audio drops sound like. It's fairly obvious and sometimes causes the sound output of an application to completely die.)

 

[toleda]

AppleHDA.kext is 2.3.1 (it came from Multibeast 5.1.1.)

I believe you may be trying to defeat a new "feature" in ML; from Mountain Lion: Optimized AppleHDA for Realtek ALC8xx
2. When headphones are plugged in, selecting another audio device is disabled until the headphones are unplugged.

How are you forcing the alternate selection (i.e., Line Out) in System Preferences/Sound/Output?

 

[racerx90]

I believe you may be trying to defeat a new "feature" in ML; from Mountain Lion: Optimized AppleHDA for Realtek ALC8xx
2. When headphones are plugged in, selecting another audio device is disabled until the headphones are unplugged.

How are you forcing the alternate selection (i.e., Line Out) in System Preferences/Sound/Output?

Yes, I selected it in the output section. If I didn't do it right, please let me know what you wanted me to test and I'll do it again.

 

[toleda]

Yes, I selected it in the output section. If I didn't do it right, please let me know what you wanted me to test and I'll do it again.

Never mind, confirmed that feature is not in 10.8.2 AppleHDA.kext_v2.3.1. Also confirmed I do not have dropouts on any any output with and without the headphones connected. I did have an instance of dropouts caused by not completely inserting the headphone plug in the headphone jack. When it happened, it resolved as soon as I completely plugged the headphone jack into the plug. At this point, I cannot replicate the problem you see, except accidentally.

Suggest you disconnect the front panel from the motherboard and test audio through speakers on each motherboard jack. Reply with results.

 

[racerx90]

Suggest you disconnect the front panel from the motherboard and test audio through speakers on each motherboard jack. Reply with results.

I will test this tomorrow and provide an update. Thanks for the help.

 

[racerx90]

With the front audio jacks completely disconnected from the motherboard, both the green (internal speakers) rear and black (line out) rear ports experience audio drop outs when playing continuous sound.

(I believe swashbuckler also tried doing this as well (as per his post to this thread), and it didn't work for him as well.)

 

[toleda]

With the front audio jacks completely disconnected from the motherboard, both the green (internal speakers) rear and black (line out) rear ports experience audio drop outs when playing continuous sound.

I don't have any other suggestions.