[Dave-in-Cambodia]

Hello and thanks again to Audio Circle for its existence. (I was a member years ago but lost all of that id-specific data after a long period away from the hobby.)

I am the proud new owner of a gently used Arcam irDAC and I love the sound, but the unit doesn't 'wake up' in time to reproduce the attack of the first note of whatever is being sent to it. There's also an audible click at both ends -- waking up and going back to sleep -- which probably annoys me more than it should. Is there a hack that will allow me to fool the unit into never going to sleep?

Source is a HP Deskmate PC, connected to the Arcam via asynchronous USB and running J River. Firmware for USB Audio-2 on the PC is brand-and-model accurate, and up to date.

[Dave-in-Cambodia]

Update:
I found a work-around that will probably send half the circle screaming from the room, but it's working. What I did was to download a YouTube video of a 40kHz audio signal, then load it on VLC and set it to loop at an extremely low volume. Doubtless this is causing all sorts of distortion and noise that I haven't budgeted for, but so far it's working. Any thoughts on just how bad an idea that is?

[richidoo]

Playing continuous signal to keep it from clicking or sleeping is a great idea, but eventually the squirrel will get his nut and you'll hear the click again.

It's not sleep, it's just the DAC takes more time to sync to the digital input signal than it should. This is normal for older DACs. It's the syncing and unsyncing of the digital input signal. See if it also snaps when you unplug the digital input cable. Some music player software allows setting a delay to starting the music playback to allow the DAC to sync first. Usually the problem is only missing the first notes, not a transient snap. That sounds like something broken.

If it makes a snap sound AFTER the music stops while playing nothing, then you may have a DC offset problem with your DAC. You can measure the output DC offset just to make sure it's not physically broken. Measure output of DAC with multimeter set to VDC. Should be <0.050VDC at all times: while playing music, while playing silent and also during sleep should be no DC on the output. It might be snapping to a DC offset during sleep.

If you have a very high sensitivity speakers (>95dB) then every flaw in the signal will be very audible and you need to upgrade to quieter electronics, or lower voltage gain amplifier, etc. 

[Dave-in-Cambodia]

I live in Cambodia, and much of what you've heard about the developing world is exactly the sort of poppycock that you might expect it to be, but not electricity -- which is so bad that it makes my head swim.

tl;dr -- a DC-offset problem would be just about the least surprising news I've gotten since I was wiped out in the stock market a couple of years ago.

In the meantime the looped 40kHz signal works just fine, as long as you don't think I'm adding things that I'd be naive to ignore. Surely a continuous hypersonic audio signal must be contributing something pernicious, no? Because if not, and given the setting and situation, I'd be inclined to let it stop working before I mess with things too much more.

[richidoo]

Never believe anything on utoob. There are no 40kHz signal on utoob. It is compressed audio which cant play higher than 20k at most.

But if the track makes your system not lose sync then it's fine and certainly safe. I think a track with dead silence would work just as well. Its not the value of the digital words, its just the presence of words on the input which allows the dac to stay synced to avoid the snap. You can make a track like that yourself using Audacity free audio editing software.

While you may have DC on your utlity power, I meant test the DAC analog output jack for DC. The dac power supply should remove DC from mains.

[Dave-in-Cambodia]

The dead silence idea is one of those "I coulda had a V8" moments. Cheers.