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Home » Hardware » Interfaces » 2882 AC power Interference from switching on/off and plugging/unplugging external audio equipment (Audio from DAW playback gets interrupted, glitches, and comes back)
2882 AC power Interference from switching on/off and plugging/unplugging external audio equipment [message #86148] Sun, 12 October 2014 17:52
BING is currently offline  BING
Messages: 1
Registered: October 2014
Location: DETROIT/NASHVILLE
Junior Member
Hi. First post. I have waited too long to join this forum! I love my 2882 2d expanded with DSP license!

Have been talking with Jon about the issue of AC power interference. Plugging/unplugging/switching on or off amplifiers, preamps, mixers, etc...

I was able to isolate a cause (or a contributing factor) of audio from DAW being interrupted and protools crashing when switching other audio gear on and off. This happened in two different locations, both with proper grounding. For example, when switching on a number of different devices such as audio amplifiers, tube microphone preamps, or plugging in the macbook pro's magsafe supply, audio playback from iTunes or pro tools would stop, fizzle, stutter, and usually start playing again. Didn't make a difference if the device causing this was connected to the 2882 via audio connection.

I was using a 10' firewire 400 cable with an 800 adapter, also going into the thunderbolt adapter. With a 6' 800 to 400 cable, the issue was not repeatable.

I fired up my older macbook pro with 400/800 ports and tested the suspect cable. Going directly from a 400 port on the laptop, the issue was not repeatable. Using the same cable in the older MBP 800 port with the 800 to 400 adapter, the issue was repeatable, though a lot less likely to occur in testing (switching on and off of tube preamp etc).

So, in summary...the combo of thunderbolt adapter>800 to 400 adapter>long 400 cable was probably compromising the grounding and connection quality, allowing spikes on the AC lines to interfere with the data stream.

I guess this was common sense...using too many adapters in line with the box.
Has anyone else had anything like this happen?

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