Please help: Unexpected distortion after upgrading DAC + speakers

[FuzzBuster]

Hi all,

Thanks for reading my post. I recently upgraded from Logitech speakers to Edifier R1280DBs and added an iFi ZEN Air DAC via USB on Windows 10. Overall, sound quality is better, but now I’m hearing distortion across basically the entire frequency range for many songs.

Some tracks sound fine, others grainy or harsh. Interestingly, Logitech speakers seemingly had no such issues (or were they just masked?) , so it’s odd that higher-fidelity gear brings this. Could it be the DAC?

I’ve tried Windows DAC settings (no enhancements, exclusive mode, Foobar2000 via WASAPI—though my Foobar test may not have been perfect), but the problem persists. Time is critical, as I may need to return one or both components if they’re defective.

Anyone else ever had or heard of similar issues? Should I consider a technician-level diagnosis, or is there something else I should check first?

Thanks!
David, near Barcelona, Spain

 

[staticV3]

Hi @FuzzBuster! Welcome to ASR.

A likely culprit is too high output voltage, clipping the Edifier's input.

I'd try:
-Turning the Zen DAC volume way down, then turning up the Edifier to compensate
-Using the Edifier's Coax/Optical input instead

 

[FuzzBuster]

Thanks for the suggestions! Just to clarify my setup:

*My DAC only has RCA stereo outputs (red + white), so it’s connected to the AUX/Line 1 input on the Edifier speakers using RCA cables.
*I see the COAX input on the speakers (single yellow jack), but my DAC cannot output coaxial digital, so I can’t test that input.
*Both the DAC and speaker volumes are set quite low, so I don’t think high levels are causing clipping.

Given this, I’m wondering if the distortion I hear could be caused by driver conflicts in Windows or some subtle mismatch between the DAC’s analog output and the speaker’s analog input.

 

[staticV3]

Thanks for the suggestions! Just to clarify my setup:

*My DAC only has RCA stereo outputs (red + white), so it’s connected to the AUX/Line 1 input on the Edifier speakers using RCA cables.
*I see the COAX input on the speakers (single yellow jack), but my DAC cannot output coaxial digital, so I can’t test that input.
*Both the DAC and speaker volumes are set quite low, so I don’t think high levels are causing clipping.

Given this, I’m wondering if the distortion I hear could be caused by driver conflicts in Windows or some subtle mismatch between the DAC’s analog output and the speaker’s analog input.

Here's how to troubleshoot these kinds of issues:

-Swap the Edifier out for a different speaker/Amp/Headphone Amp etc
->Issue gone, then it's the Edifier. Still there, then it's something else in the chain

-Swap the Windows PC out for a different USB Host device which you plug the Zen DAC into, a laptop, phone, tablet etc.
->Issue gone, then it's the PC. Still there, then it's something else in the chain

-Swap the iFi DAC out for another source device, your laptop's headphone output, a headphone dongle for your phone, the Edifier's internal DAC etc.
->Issue gone, then it's the iFi. Still there, then it's something else in the chain

 

[voodooless]

The input sensitivity is 500/600mV while DAC outputs 3.3V max. Gain issues would be the most likely candidate for issues.

 

[FuzzBuster]

@staticV3 Thanks for the detailed suggestions.

Unfortunately, I don’t have another speaker, amp, or DAC to swap in, and I’m not set up to test with another PC or device easily. Maybe a qualified tech could help me with all of that---in person. My focus for now will be updating the iFi drivers and checking for any Windows audio driver conflicts.

Appreciate your guidance — it’s all very helpful as I try to narrow down the source of the distortion.

 

[FuzzBuster]

@voodooless
Thanks for the comment.

Just to clarify, both my DAC and Edifier speaker volumes are set quite low, yet I’m still hearing distortion. Could this be a gain mismatch issue, where the DAC’s output (up to 3.3 V) is too high for the speaker’s expected input (500–600 mV)?

If you or anyone has experience testing or adjusting for this with the iFi Zen DAC and Edifier R1280DBs, any practical tips would be greatly appreciated.

 

[voodooless]

Do you have a DMM? If so, you could measure the output voltage of the DAC and make sure it’s within spec.

Can you hook up the PC to the speakers without the DAC, or have some other device that you can hook up to the speakers, like a phone? How about the Bluetooth connection? Does it have the same issues?

 

[pablolie]

...
*Both the DAC and speaker volumes are set quite low, so I don’t think high levels are causing clipping.
...

Try to set the AC output even lower, then. It's a 5 second exercise, don't dismiss it. That's exactly how clipping can happen.

 

[FuzzBuster]

Thanks for the suggestions.
@voodooless I don’t have a DMM, so I can’t measure the DAC output voltage myself. I also don’t have another device handy to test the speakers directly—my old Logitech setup can’t connect directly to the Edifiers, and I haven’t tested Bluetooth yet.

@pablolie I’ll definitely try lowering the DAC’s AC output further — I hadn’t thought it could make such a difference even at low volume.

 

[kemmler3D]

The difference between the IfI max output and the edifiers expected input voltage looks to be about 15dB, but if we assume some audible distortion could occur below that, maybe lowering the output of the DAC by 20dB would be a good test.

 

[DVDdoug]

Unfortunately, I don’t have another speaker, amp, or DAC to swap in,

Your computer has a DAC (headphone or line output). Or if you have a phone with an analog headphone output you can try that. in both cases you'll need the correct adapter cables. Or it looks like your speakers have Bluetooth.

Or you can try plugging a CD player or your TV, etc. directly into the speakers.

 

[pablolie]

Thanks for the suggestions.
@voodooless I don’t have a DMM, so I can’t measure the DAC output voltage myself. I also don’t have another device handy to test the speakers directly—my old Logitech setup can’t connect directly to the Edifiers, and I haven’t tested Bluetooth yet.

@pablolie I’ll definitely try lowering the DAC’s AC output further — I hadn’t thought it could make such a difference even at low volume.

Great - I just checked quickly, and that DAC can put out 3.3V, whereas the speakers don't like anything above 2V.

One side effect of our focus on measurements is that higher output voltages have become quite common - there is no industry standard, and SNR/THD measurements naturally are better with higher voltages, so such mismatches have become more common. Just this weekend, a friend of mine had installed a streamer and was cussing about "digital quality" (he's an analog guy), but we corrected it by matching the signals. His amp is of a venerable age and much prefers inputs under 2V (and of course the streaming/DAC vendor -like many- recommends to max out the output volume for "best performance")...

It's one thing I am not a fan of with current measurement suites, audio reviewers typically normalize to full-scale output, not to a fixed reference voltage. As someone who thinks loudness obliterates detail and finesse, I'd prefer a set reference to 1.8V for *all* components (I could not care less if something is distortion free at over 100B). I think Redbook was 2V but who remembers....
It also invites a more an more common phenomenon that, while not reducing SQ via clipping, still bothers me. When I had a Benchmark DAC2HGC an AHB2 together, the Benchmark recommendation of course was to let the DAC2 go all out. But I *hated* the fact that the loudest volume level I could stand like that was not even at the 10 o'clock volume setting on the DAC2HGC (which of course acts like a preamp too in that case).

 

[Keith_W]

You don't have your Logitech speakers any more?

 

[antcollinet]

I also don’t have another device handy to test the speakers directly

If I've read correctly the speakers have bluetooth.

Try connecting a phone via bluetooth, and playing music that way. This will eliminate any analogue input gain problems.