optical
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Post by optical on Feb 7, 2023 14:46:25 GMT
Hi all,
I've just rewired the output wires on a DAC (nothing complicated) replacing the wires going from the main board to the + of both outputs (L&R).
I've done a quick continuity check (just using nodes with an audible 'circuit made' beep) I haven't measured any voltages or resistance as the circuit is off. It seems I've got continuity on both output terminals at the same time (from one to the other).
I've had a listen and all seems okay, left and right independent channels with clear separation of instruments panning left and right (so it's not just the same signal going to each output (Mono)).
I've tried a mono to stereo recording and the mono is mono and the stereo is stereo.
There is no nasty humming or noises coming from the outputs, from what I can tell it's working fine . . . . which doesn't seem right to me.
Has anyone come across something similar or this type of design before (just seems very strange that the outputs can be 'tied' yet independent of each other?)
Thanks in advance.
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Post by firebottle on Feb 7, 2023 16:21:51 GMT
The outputs are probably shorted in a 'mute' mode when the Dac is off. So you will see continuity between L and R outputs.
If you use the ohms function it will probably read almost zero, that would confirm my guess.
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optical
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Post by optical on Feb 7, 2023 18:30:46 GMT
The outputs are probably shorted in a 'mute' mode when the Dac is off. So you will see continuity between L and R outputs. If you use the ohms function it will probably read almost zero, that would confirm my guess. Thanks Al, sounds very plausible that's the case. I don't quite understand it but I guess a 'mute' feature would go everywhere in the circuit? I suppose it would likely measure differently when the circuit is in use. Cheers. |
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optical
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Post by optical on Feb 21, 2023 8:49:33 GMT
So as I continue to devalue and destroy the resale potential of my equipment . . . . The XLR outputs on my DAC seem to sound better than the RCA outputs (not just becasue they are higher gain becasue at the same output volume measured at the listening position) they are more dynamic and I just seem to prefer them. Anyway the XLR outputs have these trim pots for fine adjustment but unfortunately I can't see how they intergrate into the circuit, I've also been told it's possible that they are attenuating the output digitally? You can see how the pots connect to the board highlighted in this pic. I've tried just disconnecting the circled clip-on plugs and then there is no output via the XLR's.  Any ideas how I can remove/bypass them at all as ultimtely it'll be better with them out of the signal path (unless they are actually not in the signal path at all in which case I'll just set them to max and leave them be). |
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Post by firebottle on Feb 21, 2023 11:11:49 GMT
Without seeing the actual tracks on the small pcb my guess would be that the input and output of the pots are on the 2 outer pins, L and R respectively.
Pull the plug from the pcb, fit a wire link into each pair of outer pins and see what happens. Or you could remove the pcb to check what the tracks look like.
.......glad to help with the devaluation.
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optical
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Post by optical on Feb 21, 2023 11:17:08 GMT
Without seeing the actual tracks on the small pcb my guess would be that the input and output of the pots are on the 2 outer pins, L and R respectively. Pull the plug from the pcb, fit a wire link into each pair of outer pins and see what happens. Or you could remove the pcb to check what the tracks look like. .......glad to help with the devaluation. Thanks Alan, yes I guess running a wire from the links back to the connections would be a good way to find out. Although there may be a 'cleaner' way to do it by removing the PCB which will cut out a few of those naff plug connectors, which can only be a good thing. I'll have a go at taking it apart myself at some point I reckon then. Cheers |
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