Distortion Problems


Hey guys,

This is a bit complex to try and explain so here I go:

I am using the ULN-8 with Logic 8. In one session (and one session only as far as I can tell) I am getting electrical sounding distortion coming from output "3". I am using analog 3-4 for my monitors right now. Strange thing is, when I switch to another output (like 5-6) the distortion goes away. I suspected it could be the cable, but why would output 3 work in another sessions with the exact same DSP settings?

So this leads me to believe that the output 3 in my unit is malfunctioning. The distortion gets REALLY bad when I enable the 12 band EQ on DAW 5-6 like the DSP is overloading or something. Its really strange and would like to know if there is anything I can do to trouble shoot this more? I am borrowing a breakout cable from a friend this weekend to test it some more to see if it is the cable. I am using I/O plugs for all these DAW inputs and FW outputs.

Here is the mixer config with DSP on it (from left to right):

DAW 5-6: Master Vocal Bus
DAW 7-8: Master Drum Bus
DAW 9: Kick
DAW 10: Snare
DAW 11: HH
DAW 12: Tom 1
DAW 13: Tom 2
DAW 14: Tom 3
DAW 15: Left Overhead
DAW 16: Right Overhead.
DAW 1-2: Master Bus

Here is where it gets REALLY strange (and only with this session, I have other sessions that have the same amount of DSP plugins that sound just fine). On the vocal bus in Logic, if I bypass the I/O plug, and still have the DSP enabled for the DAW 5-6 return in the Mio Mixer, the distortion still takes place. The more DSP I bypass, the less distortion I get. I have tried as much as I can to narrow this problem down, but it all comes down to Output Analog 3 is getting distortion noises with this DSP setup, and other analog outputs are not.

Any ideas?

Also, I tried to search how to figure out how much DSP processing I have left, but I just can't seem to locate that information on my unit, where do I go for that?



Allen Rowand

Look in the lower left side of the MIO Console window; there's a DSP Usage meter. It would be helpful to know what sample rate you're working at. It sounds like you're overloading the dsp.

I'm about to go on vacation for a week, so if you don't get any suggestions here that help please get in touch with support and Jon will help you.



I am working at 44.1 / 24 bit.

Let's say it is DSP overload, but why does the distortion dissapear with a different analog output? Also, when I switch to cans there is no distortion.

I checked my amp, my speakers, and cables (as far as I know).

Also, I am looking and I still can't find that usage meter, so you're saying it is supposed to be the bottom left side of the MIO Console, in the I/O Control Tab? When I goto the +DSP tab the meter in there doesn't show any DSP being used...



New Member
Sorry this is an old thread but I'm wondering if this was ever resolved? Because I'm experiencing a problem which sounds exactly the same as what you described here with a new ULN-8 and Macbook Pro which I've just set up. I'm currently only using analog outputs 1-2 for monitoring, and I get the electrical distortion just on channel 1 after working in Logic 9 or just playing system audio for a while.

If I know how you resolved it perhaps I can try the same thing? I'm already in discussions with the support team over email, but I think they are away for the weekend, and I really need to set up my surrounds on Monday. So any help or advice would be appreciated, thanks.