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Dull/muddy output on J99 with 990c's
Posted:
Wed Mar 19, 2008 2:56 pmby codeman015
I'm getting a dull/muddy output on my J99 with 990c's. It is knowhere near as bright as the other J99 I built. I've double checked all of the components. Could it be the opamps? Or something else? Any thoughts? Thanks!
Posted:
Wed Mar 26, 2008 10:16 amby codeman015
A little update. I tried the 797's and they do sound better, and like the other J99 I recorded with 797's. So I guess it's either the 990c's or the C8/C9 caps? Anyone?
Posted:
Wed Mar 26, 2008 1:48 pmby craigmorris74
From my experience, the 990c's are rather easy to blow during the installation testing phase. Once you've got them installed, they're fine, but I've blown a couple just trying to make a pre work. This could of course be attributed to my shaky hand causing a short.
Posted:
Tue Apr 08, 2008 11:12 amby tpryan
Try testing each JH990C in U1 without anything installed at U2. With the regulators adjusted for +/-18V to +/-24V and the input at CONN1 shorted, what DC voltage do you measure at U1, pin 6? Let us know what you find.