This is a review of the MC103 Pro XLR switch sold by Douk Audio. There are two versions with the same model name:
Here is the view of the front - please note that I took this photo with the lid unscrewed, that's why it is not sitting correctly on the right hand side.
View of the back (also taken with lid unscrewed):
The switch looks a bit cheap, neither fancy nor over the top. Front and back are plastics, bottom and top are metal (aluminium). I would have preferred a full metal housing for better shielding. The switch works precise but does not feel expensive.
Teardown
To open the housing remove 4 screws and lift off the lid:
Measurements
I used my RME ADI-2 PRO fs with +24 dBu reference level to get the highest possible Signal/Noise ratio. The cables were 40 cm long and made by me using Neutrik connectors and Klotz microphone cable. For comparison the following plots always show the loopback performance of the RME for comparison.
THD
I used a 1 kHz signal with +21 dBu level because the THD of the RME is lower at -3 dBFS than at 0 dBFS. I set REW to average 16 spectra of 32 kHz FFT size to dig deep into the noise.
As one can see there is no difference between the switch and the loopback. We can safely assume that any distortion or hum added by the switch (if any) is below that of the RME. We need an AP to dig deeper.
Crossfeed
I measured with several sinus signals between 20 Hz and 20 kHz at 0 dBFS output. We see 5 curves in 3 groups:
Results:
EDIT:
As @MC_RME has stated in posting 7 the reason for the higher crossfeed above a few hundred Hz is capaciticve coupling. He recommended to redo the test using the balanced phone output due to its much lower output impedance (0.1 Ohm vs. 200 Ohm). Here is the result:
Yep, we are more than 20 dB better at 20 kHz. Looking sharp one sees that the crossfeed of the switch is identical to the RME loopback, so what we see is the limit of my measurement rig. Well done, Douk Audio.
Conclusion
I have been asked whether this switch is an "audiophile" device and whether it could be used between a highend DAC and a highend power amp. Regarding the results I simply say yes. Both distortion and noise added by the switch are below audibility level in all home environments I can think of. Whether an audiophile wants to use such a cheap looking device in his highend system is another question I'm not going to answer.
- 3-to-1: 3 inputs (XLR female) and 1 output (XLR male)
- 1-to-3: 1 input (XLR female) and 3 outputs (XLR male)
Here is the view of the front - please note that I took this photo with the lid unscrewed, that's why it is not sitting correctly on the right hand side.
View of the back (also taken with lid unscrewed):
The switch looks a bit cheap, neither fancy nor over the top. Front and back are plastics, bottom and top are metal (aluminium). I would have preferred a full metal housing for better shielding. The switch works precise but does not feel expensive.
Teardown
To open the housing remove 4 screws and lift off the lid:
Measurements
I used my RME ADI-2 PRO fs with +24 dBu reference level to get the highest possible Signal/Noise ratio. The cables were 40 cm long and made by me using Neutrik connectors and Klotz microphone cable. For comparison the following plots always show the loopback performance of the RME for comparison.
THD
I used a 1 kHz signal with +21 dBu level because the THD of the RME is lower at -3 dBFS than at 0 dBFS. I set REW to average 16 spectra of 32 kHz FFT size to dig deep into the noise.
As one can see there is no difference between the switch and the loopback. We can safely assume that any distortion or hum added by the switch (if any) is below that of the RME. We need an AP to dig deeper.
Crossfeed
I measured with several sinus signals between 20 Hz and 20 kHz at 0 dBFS output. We see 5 curves in 3 groups:
- green/orange: crossfeed of the switch, from left to right channel and from right to left channel
- pink: crossfeed of the switch, from left channel input X to left channel input Y
- red/blue: crossfeed of the loopback, from left to right channel and from right to left channel
Results:
- Above 1 kHz the crossfeed between inputs is 12 dB higher than the interchannel crossfeed of the RME.
- Above the interchannel crossfeed between left and right channel of one input is about 24 dB higher than the RME.
- Below 1 kHz the crossfeed results suffer from the inherent noise of the RME although on a very lowe level. We can safely assume that the real crossfeed curves continue to decrease with decreasing frequency.
EDIT:
As @MC_RME has stated in posting 7 the reason for the higher crossfeed above a few hundred Hz is capaciticve coupling. He recommended to redo the test using the balanced phone output due to its much lower output impedance (0.1 Ohm vs. 200 Ohm). Here is the result:
Yep, we are more than 20 dB better at 20 kHz. Looking sharp one sees that the crossfeed of the switch is identical to the RME loopback, so what we see is the limit of my measurement rig. Well done, Douk Audio.
Conclusion
I have been asked whether this switch is an "audiophile" device and whether it could be used between a highend DAC and a highend power amp. Regarding the results I simply say yes. Both distortion and noise added by the switch are below audibility level in all home environments I can think of. Whether an audiophile wants to use such a cheap looking device in his highend system is another question I'm not going to answer.
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