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Is there any reason why the output should be coming as shorted?
i have tested between the + / - / gnd pads in both Left and Right channels
each channel is apparently shorted to the other...
the reason i ask is when i try to drive balanced headphones i am getting distortion at loud volumes (directly wired to output)
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There is an output relay that shunts the outputs to GND when the power is off. Each output would be shorted to the other because they are both shorted to GND when the power is not applied. I would have to know more to answer the rest of your post. Cheers! Russ Edited by user Saturday, November 21, 2009 8:52:07 PM(UTC)
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im also getting a shorted read while the dac is on as well... I was wondering if that could be causing problems that im experiencing ?
distortion mainly
I have a single ended AND xlr outputs wired at teh same time no switch in between them... whatever other information you need let me know.
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What voltages are you using for the analog sections?
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15 volts
and its not dual mono using 1 psu for both L and R
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Are you just overdriving the headphones?
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i dont believe so distortion starts coming into play before i really even amplify it much... or can the buffalo not handle too much ? headphones are hd 650's
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That's not the problem then... the Buffalo can output up to 150Ma per channel. Can you check the analog power supply voltages (carefully) when you get the distortion to see if they are drooping at all?
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When distortion is occuring im getting +14.25 on the positive rail and - 15.02 on the negative rail
is the positive supposed to be lower ?
if i turn the volume(digital) down really low and drive only with my amp it sounds much cleaner.
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Try jumpering the 3W resistors (R1, R2, R5, R6) on your LCBPS. ( Where is the green lines are in the layout). They may be restricting the current too much. You can just tack on some little wires on the bottom of the board. scrap resistor leads will be perfect for this. Edited by user Wednesday, December 2, 2009 7:10:23 AM(UTC)
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I do think that helped a little the voltage is now tracking at +15 on the positive rail when being driven as well... but i can still hear a little bit of distortion if i use full digital volume... so im just turning it down some and letting my amp drive it... when i do that it sounds fine
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I was under the impression you were driving the headphones directly. You are driving an amp from the Buffalo which are powering the headphones?
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yes i am using an amp in my main setup ... i tried driving the headphones directly but i received heavy distortion so i stopped and went back to my old setup, but interestingly if i turn up full digital modulation even at very low volume i hear distortion in the headphones but if i turn digital volume down i can drive the headphones very loud without any distortion
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It sounds like the output level of the Buffalo may be overdriving the input stage of you amplifier.
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anyway to reduce that ? or just do what im currently doing.
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The user manual discusses how to adjust the output voltage swing.
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