Need H/W Help: I have the following setup for sound on my PC: PC------>DAC-------->Speakers (DAC: Digital to Analog Converter) The DAC is connected to the PC via USB3. I have been...

TheShoe Loc: Lacey, WA

I have the following setup for sound on my PC:

PC------>DAC-------->Speakers (DAC: Digital to Analog Converter)

The DAC is connected to the PC via USB3.

I have been getting loud, sometimes very loud, bangs through the speakers whenever the PC is powered on and whenever it wakes up from sleep. I have determined that it is due to a buildup of static while the PC is dormant.
My question for those on UHH who know more about electricity than I, bound to be very many if not all of you, is there any way to eliminate this problem? I am circumventing it by (a) disabling Sleep, and (b) disconnecting the DAC from the PC immediately following Shutdown.
It would seem that putting the DAC on a grounded conductive pad might be a solution; however, there may bad effects from doing so.

Longshadow Loc: Audubon, PA, United States

I'll guess not static, but a "pop" when the sound line is activated when the computer wakes and power (albeit no sound signal) to the audio line comes active.

My tuner/amp <speakers> sometimes pop/click when I turn it off.
I just ignore that.

BebuLamar

I would say try a new DAC. I think the DAC makes the pop when it first recognized by the PC.

TheShoe Loc: Lacey, WA

Longshadow wrote:

I'll guess not static, but a "pop" when the sound line is activated when the computer wakes and power (albeit no sound signal) to the audio line comes active.

My tuner/amp <speakers> sometimes pop/click when I turn it off.
I just ignore that.

Mine is definitely a static discharge that could be used as sound effects for a large caliber gun shot. This is a problem, not an annoyance.

Longshadow Loc: Audubon, PA, United States

TheShoe wrote:

Mine is definitely a static discharge that could be used as sound effects for a large caliber gun shot. This is a problem, not an annoyance.

It would be interesting to see what causes the static buildup.

TheShoe Loc: Lacey, WA

BebuLamar wrote:

I would say try a new DAC. I think the DAC makes the pop when it first recognized by the PC.

It has happened with two different DACs, both were Audioengine D1s, one was brand new. That pop is in a whole different league. Mine is much louder than a mere pop that can be ignored.

burkphoto Loc: High Point, NC

Sounds like a question for Tri-X to answer. He's one of the best audiophile experts here, as he has designed and built lots of equipment.

My hunch is that there is some sort of capacitor discharge or inrush of current causing the pop. Can you simply turn the volume down to zero? If it truly is a static issue, grounding the entire setup seems prudent. Modern audio gear without a solid earth ground (not just the neutral) is both rare and can be unsafe.

TriX Loc: Raleigh, NC

burkphoto wrote:

Sounds like a question for Tri-X to answer. He's one of the best audiophile experts here, as he has designed and built lots of equipment.

My hunch is that there is some sort of capacitor discharge or inrush of current causing the pop. Can you simply turn the volume down to zero? If it truly is a static issue, grounding the entire setup seems prudent. Modern audio gear without a solid earth ground (not just the neutral) is both rare and can be unsafe.

Thank you for the kind words Bill, but I think you’ve covered it. Frankly, static would not be my first guess. For a static build up to occur, you need an open input somewhere in the signal chain, and if the DAC stays plugged in on both the USB and and analog end, I don’t see where that could occur. I think (and it’s only a guess) that it’s the computer powering up the USB port when it’s turned on or coming out of sleep mode. This is a common problem with receivers or amps to the extent that many have a delay circuit that prevents output to the speakers for a second or so on power up to prevent this “pop”. I have two suggestions: first, as Bill said, just turn down the amp gain before you bring up the computer. Secondly if this is a Windows machine, go to control panel / power settings / advanced /USB and disable power down USB ports in sleep or hibernate mode. Restart the computer and see if that makes a difference (it will keep the USB ports powered up all the time when the computer is on, regardless of the computer state).

Please let us know if that helps.

burkphoto Loc: High Point, NC

TriX wrote:

Thank you for the kind words Bill, but I think you... (show quote)

Thanks!

Yes, a good power amp has relays in it to protect speakers. When you turn it on, the speakers are disconnected for a couple of seconds while the filter capacitors charge and the circuits reach operating power levels. Then you hear the relays click and the speakers are in circuit. I used a high power sound reinforcement amp that was dead quiet on startup because it was built that way. The faint relay click was my cue that the 600 Watts RMS amp was ready.

Without those relays, the speakers could get a huge jolt of power with a clipped, distorted wave form that could rip the voice coils from the cones. Anyone in the audience of our small performance hall would be emotionally disturbed and momentarily deafened by that... We used Klipsch La Scalas. They kicked out 105 dB each from 1 Watt at 1 Meter... Fortunately, we had a fast attack "brick wall" audio peak limiter as the last component between the P.A. mixer and the amp, so if someone dropped a mic or hit the mic with guitar strings, the peak would be clamped at a reasonable level.

TheShoe Loc: Lacey, WA

TriX wrote:

Thank you for the kind words Bill, but I think you... (show quote)

Disabling power off during sleep, for all USB hubs, was one of my first attempts at solving this. Prior to that, I tried the experiment of unplugging the USB cable immediately after putting the PC to sleep. When I touched the aluminum case of the DAC when unplugging the USB cable, my finger was bitten by a spark. The longer that I let the computer sleep before unplugging, the greater the spark.

Instead of fiddling with the gain, I am going to use a USB hub that has a switch for each port. The switch is binary; adjusting the gain, analog.

Your guess is probably correct, however, the problem cannot really be corrected by software or manual intervention. Either of those is just a circumvention.

TheShoe Loc: Lacey, WA

Thank you Bill and Trix for your helpful responses. Trix, If you grant me permission, I will send your comments, anonymously, about the delay to AudioEngine. They have dismissed my problem reports with no apparent effort to solve the problem.

Canisdirus

I would also hook up the dac with a coax or any other available source...
To see if it is indeed USB static problem...

I doubt the DAC is the culprit...just a line carrier.

BBurns Loc: South Bay, California

As another old engineer, I will offer my 2 cents worth.

Most homes are supplied single phase power, a 3 wire/220V service.
This still give you 2 lines of service which a good electrician will load balance.
Make sure all of your devices are connected to the same side of your power source.
All devices must be connected to a common single point ground.
Hopefully this will help.

burkphoto Loc: High Point, NC

BBurns wrote:

As another old engineer, I will offer my 2 cents worth.

Most homes are supplied single phase power, a 3 wire/220V service.
This still give you 2 lines of service which a good electrician will load balance.
Make sure all of your devices are connected to the same side of your power source.
All devices must be connected to a common single point ground.
Hopefully this will help.

That can be accomplished with a single power strip, or multiple power strips connected to a single circuit. Computer, monitor, DAC, audio amp, and any other peripherals should run off the same AC phase, whether the incoming power is split phase 120/240, or 120/208 volt service coming from a three phase source.

Canisdirus

If it's a power issue...and dirty power is everywhere...

First thing is to separate all power and line cables...or have them cross each other at 90 degrees.
If you touch the offending unit and it quiets down...you probably have some ground interference going on.

The simplest and probably cheapest overall solution is to get a priority power component.

https://www.amazon.com/Panamax-MR4300-Management-Protection-Conditioning/dp/B00ILH7KJI/ref=sr_1_6?keywords=audio+power+conditioner&qid=1658947595&s=electronics&sr=1-6&ufe=app_do%3Aamzn1.fos.f5122f16-c3e8-4386-bf32-63e904010ad0#customerReviews

It goes far beyond power strips and such...and battery backups are...for computers...not power clarity.

Although...if you want the very best power...the quietest power ever...
You use a Bluetti solar generator (as a random example).
Nothing beats battery power properly presented to audio gear....absolutely dead quiet powah.
Quite a few serious audiophiles run their incredibly expensive gear on...batteries.

As a final tip...listen really late at night...like 2 or 3 am.
It's when public utility power is at it's best.