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Hi Russ, Brian,
Since I use my IVY after a Buffallo 24 as an I/V - pre to drive the balnced inputs of my power amp, I was wondering wether I am reaching the limit of the OPA1632 since my interconnect has a capacitance of 68 pF/m. The main problem I have is that during heavy bassy sounds or busy music passages I get some noise superimposed with the music. I ask because the OPA1632 datasheet does not mention enough info regarding the capacitive load drive of the opamp, whereas the THS4131 equivalent specificaly states that for loads higher than 10pF resistors should be added in series (similar to what you do with the 49720).
Any pointers of what to check whould also be welcome.
Thanks,
Abraham
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What version is your IVY board? I know the 2.0 version has spots for 21R output resistors to deal with this, and am pretty sure 1.0 did not. I would have to look at 1.1 and 1.2 versions to be sure. If you need to, you can add 21-22R resistors in series with the outputs to help isolate the capacitive load... or use a lower capacitance interconnect.
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Hi Abraham. Because the IVY was used a lot to drive headphones there is no output resistor for the balanced outputs. If you are driving capacitive cables I would definitely add around 21R in series with the outputs. This is something I have changed in IVY II. Cheers! Russ Edited by user Wednesday, November 4, 2009 9:03:25 PM(UTC)
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Rank: Member
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Thanks guys, I will try the 21R resistor option, the interconnects will have to stay I guess! This is a trick probem to solve especially since the unbalanced output is flawless! That's why I thought about the capacitance issue.
Thanks again,
Abraham
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