That explains one ... kind of.mediatechnology wrote: ↑Sat Jun 10, 2017 12:52 pmTo provide gain rolloff at AM RF frequencies is why I've tried them.Not sure why you need 2 inductors in gain leg, is the gain pot mounted at some distance in a noisy environment? In the past I have driven the gain pot cable shield to reduce capacitance effects.
in that case you may want to add small Rs in series with the base (inputs) to preferentially steer fault current to the external diodesThe internal diodes are not "strong" enough. That is what drove me to blow up lots of THAT1510s: http://www.thatcorp.com/datashts/AES790 ... eturns.pdfThe THAT chip probably has clamp diodes inside so added external ones (D1,D6) are at best redundant.
This design looks like 10uF phantom blocking caps with 10r already in series. Unless this is being used in a studio with a patch bay and operators who like to short (charged up) inputs for amusement, perhaps not needed.
Yup... between cellphones and wifi far more RF than the good old days.I believe the current thinking is a delta-connected three capacitor network. Previously it was wye. (Or is it Wye?)I don't see any Cs to ground at input... high RF and input rectification could be an issue, what does THAT recommend in their app notes (I'm too lazy to look)?
I would definitely put locations on the PC board for three RF caps.
I've had pretty good results in a modestly high AM RF environment with the flat phono preamp with a differential C (which also happens to be Cload) and input series resistors to prevent CM RF rectification.
JR