Question O2 Dac/Amp + JBL LSR 305 distortion troubleshooting

Nov 14, 2019
Hi there, I've got an issue relating to my O2dac/amp (device) which was purchased sometime in 2015.

The device is used with a Sennheiser HD 650/ JBL LSR 305 and connected to my laptop via usb. I recently changed the setup and replaced the laptop with a brand new self built desktop pc (5 days old). I plugged the device to my laptop and realised that the speakers were emitting a crackling/ buzzing sound. The headphone port was fine without any buzzing/ distortion. Unfortunately as of today, even the headphone port had a buzzing/ distortion to it. I tried both my IEM and HD 650 and both were able to replicate the noise. Distortion/ noise on the speakers got worse.

The speakers are connected on a separate power strip to the PSU (power supply unit), but both power strips are plugged in to the wall next to each other. I moved the PSU connection to another wall outlet further, but the noise remains.
I have tried plugging the device via usb to all the usb ports on my pc and there's no change in the noise.

The noise gets worse when I launch a game, the audio gets crackly and distorted and louder.

I have plugged the speakers to my phone and played off it, no issues.

Note: when the speakers are just plugged in, powered on, not connected to anything its noisefloor is slightly audible (which was not an issue when I was using laptop). Am connected to internet via LAN, have tried onboard WiFi with antenna and LAN, both have the noise.
  1. What is causing the interference? PSU/ GPU? Bad shielding? Power loop etc?
  2. Could it be the device failing?
  3. Is the desktop PC introducing some form of electrical disturbance which would warrant a power conditioner?
CPU: AMD Ryzen 5 3600
Motherboard: Gigabyte x570 Aorus Pro WiFi
Ram: Corsair Dominator Platinum 32GB
SSD/HDD: Intel 760p nvme (OS)/ Adata SX8200 Pro
GPU: Gigabyte 2070S Gaming OC White
PSU: Fractal Design Ion+ 660w Plat
Chassis: NZXT H510 Elite
OS: W10 Pro 1903


OK to get this straight you have an O2 connected via USB to a new desktop and there's noise where there wasn't before with the old laptop?

Tried a different USB cable and port? You shouldn't need drivers anymore since the Windows 10 update last year I think it was.

Your O2 has the RCA outs and those are connected to the JBL's?


OK just reread that you'd tried all the ports. Try another cable at least.

There shouldn't be anything there introducing noise like that. Anything if you connect to the old laptop on the same power strip? Another outlet?
Nov 14, 2019
Just tried connecting my laptop on the same power strip as the speakers, no distortion whatsoever. picture shows what's connected. The output is at the back of the device, I don't have another cable that I can try as the connector to the device isn't usb.

Can't insert image via the forum's interface hence the url.
Last edited:


Do you have a powered USB hub? My Z170 board doesn't like switching between multiple external DACs but an Anker, powered USB hub fixed it.

That's one of the older O2s with front power. I don't think JDS or Mayflower make them like that anymore. Even the Massdrop O2 is rear.
Thread starter Similar threads Forum Replies Date
Ryuseii Audio 2
johnmetro Audio 1
centaurussa Audio 1
G Audio 0
J Audio 1
N Audio 1
A Audio 0
M Audio 0
omaromarica Audio 1
FoleySkids Audio 1
Oaknn Audio 1
M Audio 1
O Audio 1
kevinrlewis Audio 2
Max Ski Audio 2
C Audio 1
jdip13 Audio 1
IntrepidBongos Audio 0
rclr Audio 2
C Audio 0