Is PC audio output dangerous?

[nqa3]

From https://electronics.stackexchange.com/a/298589/256935

Audio output circuitry usually does contain DC blocking capacitors... certain high end "audiophile" power amplifiers do not. With these amplifiers, any DC voltage offset on the input signal can easily blow the speakers.

I ordered a Hyperx Ncore NC122MP power amplifier (review in Fr) and it's specifically warned the source must be DC free.

But the spec of my onboard audio chip says In standby mode the ALC892 turns on DC bias on all analog input and output ports... to avoid 'Pop' noise while the system is in power on and power off transition (+3.3V on DVDD and +5VA on AVDD)

I'm looking to replace the onboard audio with an external sound card like Creative's, but unable to find any information about that. Is it supposed to be a concern? Should I add a DC blocking capacitor or something with the capability? Typical stereo DAC is unsuitable because I'll need 5.1 from PC.

 

[RayDunzl]

It would appear that the outputs are already capacitor coupled:

 

[nqa3]

It would appear that the outputs are already capacitor coupled:

Thanks a lot! (I can't understand most of the PDF myself) If this is common practice, why is it specifically mentioned though? Are there some sources that might produce DC biased output?

 

[ElNino]

Thanks a lot! (I can't understand most of the PDF myself) If this is common practice, why is it specifically mentioned though? Are there some sources that might produce DC biased output?

No properly functioning gear should have DC offset, but sometimes you find it in older tube audio gear or occasionally out-of-spec vintage gear. Other major culprits are "modded" gear by people who don't know what they're doing, and oddball high-end audio gear where someone decided that both coupling and DC servos were "bad".

 

[nqa3]

Thanks you both!! Now I'm finally relieved

 

[Vasr]

Connecting your PC directly to a power amp (especially with gobs of power) is potentially dangerous for a different reason. You have to rely on the soft volume control within the sound card application or the Windows Sound Engine to control volume. There are far too many scenarios where you can land up sending max volume inadvertently in such a situation that might blow your speakers or your ears whichever is more fragile.

Always have a unit with a hardware volume control in the path before a power amp.

 

[whazzup]

Connecting your PC directly to a power amp (especially with gobs of power) is potentially dangerous for a different reason. You have to rely on the soft volume control within the sound card application or the Windows Sound Engine to control volume. There are far too many scenarios where you can land up sending max volume inadvertently in such a situation that might blow your speakers or your ears whichever is more fragile.

My ears are definitely not fragile. They're so tough nothing vibrates them.

 

[nqa3]

Always have a unit with a hardware volume control in the path before a power amp.

Would a simple passive amp like Nobsound's be sufficient? I could put one per two channels and then one in front of subwoofer etc, with fixed volume. EDIT: Perhaps not needed for active subwoofer?

 

[Vasr]

Would a simple passive amp like Nobsound's be sufficient? I could put one per two channels and then one in front of subwoofer etc, with fixed volume. EDIT: Perhaps not needed for active subwoofer?

Taking the digital out of the PC to an outboard DAC with volume control is safer and likely cleaner.

You have four potential options (depending on your location):
1. A simple USB pro-audio interface that can do 6 to 8 channels and has volume control. Most of them have very good DACs. Won't get remotes and such.
2. An old brand-name AVR with pre-out used/clearance since you need a relatively high-end to get multi-channel pre-outs
3. Cheap audio extractors (HDMI/USB) with volume controls around US$100 (look for ones with decent reviews, don't use them for video)
4. A USB Soundcard with volume control

 

[nqa3]

You have four potential options (depending on your location):
1. A simple USB pro-audio interface that can do 6 to 8 channels and has volume control. Most of them have very good DACs. Won't get remotes and such.
2. An old brand-name AVR with pre-out used/clearance since you need a relatively high-end to get multi-channel pre-outs
3. Cheap audio extractors (HDMI/USB) with volume controls around US$100 (look for ones with decent reviews, don't use them for video)
4. A USB Soundcard with volume control

1: Any suggestion on this? I can only find stereo preamp and something like NAD M17
4. was going add a USB soundcard yes. Not sure if their volume control is by hardware... Maybe Creative Sound Blaster X3 ?

 

[Vasr]

1: Any suggestion on this? I can only find stereo preamp and something like NAD M17
4. was going add a USB soundcard yes. Not sure if their volume control is by hardware... Maybe Creative Sound Blaster X3 ?

Did you mean 1 or 2? For 1, look for 6x6 or 8x8 usb audio interfaces.

For 2, go through this thread for some ideas https://www.audiosciencereview.com/...ng-for-the-buck-for-avr-with-pre-output.2387/

Look for currently available equivalents of those. Typically AVRs not pre-amps which are expensive. You get an AVR with pre-outs to feed your external amps and ignore their internal amps. This can be done for cheaper than looking for a multi-channel pre-amp only.

 

[dfuller]

1: Any suggestion on this? I can only find stereo preamp and something like NAD M17

Depends how much you want to spend. An Okto DAC 8 could do the trick if you just want multichannel outputs.

 

[nqa3]

Depends how much you want to spend. An Okto DAC 8 could do the trick if you just want multichannel outputs.

Thanks! But an Okto DAC 8 Pro is over $1000 - what would justify the cost compared to a $100 sound card like Creative's? Would the differences of analog performance be audible from speakers, e.g. -120 dB vs -90 dB SINAD or 0.00003% vs 0.1% THD?

I don't need mic, headphone on it or any professional audio adjusting app, and from others' review Nobsound's cheap preamp could keep down the loss of quality if cable is very short and volume is low - Does this matter since I can control volume at PC source and only need preamp as safeguard?

PS: I hope to spend as little as possible on this without compromising performance, since I will also need $$ for subwoofer and other speakers... Could get a separated, two channel DAC and preamp for headphone later.

 

[nqa3]

Update: Nobsound's sucks. Medium volume and it feels a bit muddy. can't afford a good one so I will just run without preamp...

 

[Kal Rubinson]

Thanks! But an Okto DAC 8 Pro is over $1000 - what would justify the cost compared to a $100 sound card like Creative's? Would the differences of analog performance be audible from speakers, e.g. -120 dB vs -90 dB SINAD or 0.00003% vs 0.1% THD?

Take a look at miniDSP products.