PortalKeeper
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- Feb 8, 2023
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Hello all. I have an Audiophonics LPA-S400ET power amp and I was wondering if it has any of these so called protection features I've been hearing about. Does anyone know what it cannot protect against?
Main reason I ask is I have this headphone amp (Sterling SHA4) I got awhile ago at a guitar center for a jam. I recently sold my DAC and wanted to try to temporarily power my KEF Q950 tower speakers with my PC's motherboard's line out port which is a stereo TRS unbalanced output. This headphone amp, if you have a moment to look at the manual, supposedly supports a single unbalanced stereo input (one TRS cable) for the two sources 'A' and 'B' that you can switch between. It also has balanced link out ports (which I believe are at line level) to daisy chain to other equipment (this is what I hooked my power amp's left and right channels to). I wasn't expecting tremendous volume from this setup as my power is set to medium gain and line level is 1V which is a quarter of full power (I think?). Well I didn't get any sound from this setup no matter how much I tried to switch between sources on my PC or turned up the input level gain knob on the headphone amp. I concluded that this unbalanced stereo input is broken.
I tried then connecting this unbalanced stereo signal from my PC to the balanced left input for source 'A' and it worked! But the sound was muddy in the midrange and so you could not really hear much singing. The sound was coming out of both left and right speakers thankfully which the manual said would happen, but my theory on why it sounded bad is because of this common mode rejection stuff with balanced inputs. I think maybe the parts of the positive signal is being canceled out by everything panned to the right (as the right channel is now the negative) in the song that you are listening to. Am I thinking about this correctly? Thank you for any of your information on this subject.
Main reason I ask is I have this headphone amp (Sterling SHA4) I got awhile ago at a guitar center for a jam. I recently sold my DAC and wanted to try to temporarily power my KEF Q950 tower speakers with my PC's motherboard's line out port which is a stereo TRS unbalanced output. This headphone amp, if you have a moment to look at the manual, supposedly supports a single unbalanced stereo input (one TRS cable) for the two sources 'A' and 'B' that you can switch between. It also has balanced link out ports (which I believe are at line level) to daisy chain to other equipment (this is what I hooked my power amp's left and right channels to). I wasn't expecting tremendous volume from this setup as my power is set to medium gain and line level is 1V which is a quarter of full power (I think?). Well I didn't get any sound from this setup no matter how much I tried to switch between sources on my PC or turned up the input level gain knob on the headphone amp. I concluded that this unbalanced stereo input is broken.
I tried then connecting this unbalanced stereo signal from my PC to the balanced left input for source 'A' and it worked! But the sound was muddy in the midrange and so you could not really hear much singing. The sound was coming out of both left and right speakers thankfully which the manual said would happen, but my theory on why it sounded bad is because of this common mode rejection stuff with balanced inputs. I think maybe the parts of the positive signal is being canceled out by everything panned to the right (as the right channel is now the negative) in the song that you are listening to. Am I thinking about this correctly? Thank you for any of your information on this subject.