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dirkwright  
#1 Posted : Friday, August 10, 2012 5:07:26 PM(UTC)
dirkwright

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I was wondering if it would be a good idea to put small capacitors in place of the I/V resistors on the COD board if I don't intend to use the passive I/V feature. I was wondering if these small caps would help prevent RFI from getting into the Iout pins on the DAC and/or help filter out some of the RF noise coming from the Iout pins. I was thinking of something like 100pF to 100nF range.
Brian Donegan  
#2 Posted : Friday, August 10, 2012 5:53:59 PM(UTC)
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I would just handle that in your I/V stage.
dirkwright  
#3 Posted : Sunday, August 12, 2012 6:11:37 PM(UTC)
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OK, thanks. Can I put the digital section in a separate box from the I/V converter and connect the two by short cables? The PCM1794 has balanced outputs, so I would be using XLR connectors and balanced microphone cable of less than a meter long (probably a half meter or so). Would the DAC output current signal be degraded by the cable capacitance and/or connector resistance?
Russ White  
#4 Posted : Sunday, August 12, 2012 11:54:34 PM(UTC)
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Yes it is actually possible. I would not suggest it myself (and I never have tried it), but it should work.

The the cable parasitics will have some effect, but its hard to say if it will be negative or not.
dirkwright  
#5 Posted : Monday, August 13, 2012 12:03:53 AM(UTC)
dirkwright

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Originally Posted by: Russ White Go to Quoted Post
Yes it is actually possible. I would not suggest it myself (and I never have tried it), but it should work.

The cable parasitics will have some effect, but its hard to say if it will be negative or not.


OK, thanks. Maybe some of the cable capacitance will help round off some of those hard edges in the output waveform.

One reason I asked is because I already have a couple of boxes that would work, but on the other hand I thought it might be a good idea to separate the digital from the analog in separate boxes. Then I would put the power transformers for the I/V section in a third box... haha. THREE boxes for the DAC.

Otherwise, I have to buy a big box and have a good wall between the digital and analog sections.
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