A & K Kann Cube XLR to RCA issue
Mar 26, 2020 at 1:26 AM Thread Starter Post #1 of 1


New Head-Fier
Dec 6, 2019
Got the Cube recently and came across a problem. I know the info says XLR line out is balanced, but didn't expect any drama when using XLR to RCA stereo inputs, or 3.5 to RCA. (My amp does not have XLR input.) With either set up, you get a sound spike when first starting a song and a quieter one when stopping it. The supplier's technician checked out my device & cables and reported as follows:
“Kann Cube switches off the output amplifier at 3 seconds after the song is stopped.
When you press play before that 3 seconds time limit then there is no "thump".
When you press play after that 3 seconds time limit then the amp suddenly powers on (like flicking on the power switch on an amp), and this is when you hear the "thump". Because this thump is a common mode noise, a proper balanced connection will completely cancel it out, which is the whole point and benefit of using the balanced connection (see image for XLR). However, if you use only one side of the balanced (i.e. XLR to RCA adapter) then the noise will not be cancelled so the amp will get hit with the sudden thump.
AK probably doesn't consider this thump as a problem, because it is completely eliminated when you use the balanced connection as intended. Unfortunately the only way to eliminate this thump is to add some kind of filter into the cable, which will deteriorate the sound.
Many other brands will have a relay switch which mutes the outputs during the power-on period, but the KANN Cube doesn't have it.”
The RCA cable is not designed to be used with the XLR on the Kann. The Kann has been designed to switch off the amp when not in use (possibly to save on battery) when you play music, it will power up the amp again and will make a noise.
With a balanced cable, the way balanced is designed, it will cancel out the pop, but with the RCA adapter, it removes the benefit of this design.”

Apparently an update can fix this. Here's hoping !!

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