- Thread Starter
- #21
Many thanks for all the info.
I have taken a lead to the -ve output of the SMPS from the earth ground that forms a star ground for the system. I hope you can see this in the attached photo. The SMPS has mains L-N-E inputs on the far left (that come from a fused switched mains socket at the bottom right) followed to the right by 3 -ve DC outputs connected in parallel and then 3 +ve 47V DC outputs. The star point I used is at the upper middle left connected by a tab underneath to the SMPS chassis that is itself connected to the main amp chassis. Apologies to anyone who is offended by the look of the amp and its connections but is difficult to pack 6-channels even into a 19" 3U case - and I am more interested in sonic beauty than visual beauty in this case! And of course safety.
It has now completely removed any hum, even when the output from the DEQX preamp/processor is at full volume - with no music playing! Note the the DEQX outputs I use are balanced (though it also has unbalanced ones) connected to the amp through good quality XLR cables - 6 of them for the 3-way active speakers.
I have therefore not connected the inputs ground (I suspect the DEQX connects its output ground to earth).
I think this now gives me confidence to reorder the stereo amp module from 3e Audio that they insisted I return under warranty.
Thanks again,
Rod
I have taken a lead to the -ve output of the SMPS from the earth ground that forms a star ground for the system. I hope you can see this in the attached photo. The SMPS has mains L-N-E inputs on the far left (that come from a fused switched mains socket at the bottom right) followed to the right by 3 -ve DC outputs connected in parallel and then 3 +ve 47V DC outputs. The star point I used is at the upper middle left connected by a tab underneath to the SMPS chassis that is itself connected to the main amp chassis. Apologies to anyone who is offended by the look of the amp and its connections but is difficult to pack 6-channels even into a 19" 3U case - and I am more interested in sonic beauty than visual beauty in this case! And of course safety.
It has now completely removed any hum, even when the output from the DEQX preamp/processor is at full volume - with no music playing! Note the the DEQX outputs I use are balanced (though it also has unbalanced ones) connected to the amp through good quality XLR cables - 6 of them for the 3-way active speakers.
I have therefore not connected the inputs ground (I suspect the DEQX connects its output ground to earth).
I think this now gives me confidence to reorder the stereo amp module from 3e Audio that they insisted I return under warranty.
Thanks again,
Rod