Audiophiles: iTunes Equalizer making Static, Noise, Distortion

Hello,

Replaced a 2012 MBP with a late 2015 iMac and the Equalizer in iTunes now generates noise. I have a very good desktop audio system and have isolated it to the EQ. I'm using an external DAC so it's in the USB output. Anyone else experience this? Or know if the EQ occurs in the digital domain (likely) and not a round of D/A and A/D conversion. I'm guessing the hardware was cheapened. Really unhappy about it as a solid and clean system-wide equalizer is a unicorn but at least iTunes has (had) a good one. And yes, I have Boom 2.

Thanks!

I'm using an external DAC (Digital to Analog Converter) so I am using neither the headphone port nor the built-in speakers. It uses digital USB audio from the Mac. Yes, I have tried many things, including rebooting. The noise is more frequent/prominent the larger the settings on the iTunes Equalizer, e.g. 8db boost is noisier than 4db boost. Happens during loud moments of songs- which implies that it is overloading and clipping. Thanks.

Makes the Equalizer useless- not a solution.

I don't know if you all can see my original post but I cannot. So in case Apple is blocking it for some reason:

Hello,

Replaced a 2012 MBP with a late 2015 iMac and the Equalizer in iTunes now generates noise. I have a very good desktop audio system and have isolated it to the EQ. I'm using an external DAC so it's in the USB output. Anyone else experience this? Or know if the EQ occurs in the digital domain (likely) and not a round of D/A and A/D conversion. I'm guessing the hardware was cheapened. Really unhappy about it as a solid and clean system-wide equalizer is a unicorn but at least iTunes has (had) a good one. And yes, I have Boom 2.

Thanks!

So it looks like my original question is indeed being blocked. VERY frustrating.

Hello,

Replaced a 2012 MBP with a late 2015 iMac and the Equalizer in iTunes now generates noise. I have a very good desktop audio system and have isolated it to the EQ. I'm using an external DAC so it's in the USB output. Anyone else experience this? Or know if the EQ occurs in the digital domain (likely) and not a round of D/A and A/D conversion. I'm guessing the hardware was cheapened. Really unhappy about it as a solid and clean system-wide equalizer is a unicorn but at least iTunes has (had) a good one. And yes, I have Boom 2.

Thanks!

Thanks for suggesting but the volume gain, at any point, has no impact. The source is within the eq itself. Anyone use a DAC? You need to be using an external DAC to experience the issue.

No, no driver. Plug and play. Most DACs are. Just shows up like USB speakers or headphones.

Did you check the DAC manufacturer's web site for any firmware updates, to support the latest Mac hardware and software?

NOT in the DAC. I have another DAC and same result. I can get same result with USB headphones (which obviously incorporate a basic DAC).

Is this USB device powered by the USB port? Or does it have its own power supply (so it only gets audio signal data from the USB port)?

See above.

If this USB device is older, from before current USB 3.0 ports, and you own an old self-powered USB hub that is USB 2.0, try connecting the hub to the Mac and connect the DAC to the hub (as a test). "Self-powered" means it has its own power supply (does not draw power from the USB port).

Tried it all ways including through/not USB hub. No difference. It's in the computer.

If you have not already, try using several different USB cables to see if there is any difference (assuming the DAC has a separate cable, not built-in).

Yes, did. No difference.

Just to confirm, in System Preferences Sound pane Output tab, when you select the DAC there as the output device, there are no controls on that pane that affect audio output strength.

Correct, for all 3: Audioquest DAC, Topping DAC and Logitech USB headset.

More experiments:

Tried using my iPad as the USB audio source (this can be rigged although Apple makes the iPad nominally incompatible with generic USB devices) and the problem disappeared, so it is certainly something about the iMac. I tried listening with high-end headphones loud and found that the static remains with the EQ off, it is just much quieter. The static noise must be in the same frequency range as I have the EQ boosted. So it's not created by the EQ function but is from the computer as an audio source. Still convinced this is a hardware thing. I migrated everything from a MBP at the time this arose. Never a problem with the MBP

Analog output is clean straight to headphones or speakers- it's only the USB digital out. I have no way to try the Toslink digital output as neither DAC has a matching input. (piggyback on the headphone out with a little adapter) I could throw out my DAC but it really does sound better than analog out. Maybe I'll ask Santa for a DAC with Toslink- optical connections are much less trouble prone but I'll lose volume control from the computer.

Still hoping there might be some DAC users that have messed with this.

Thanks for the help.