[sdiy] Dual 914 diode in a SOT-23 package?

[blacet at blacet.com]

I found this circuit to be quite puzzling. Generally, input protection for
an op amp is covered by the nominal 100K resistor used for audio circuits.
That may not be helpful for really large voltages like 220 line voltage
but that would be an accidental and rare occurence. Not something the
average designer would be expected to cover.

Op amps are really quite robust. Some special types might need further
considerations but not your typical synth useage ICs.

>> The circuit that you have drawn is suitable for DC and near DC uses.
>> like for a control voltage. Its really
> NOT good for audio rate circuits where the leakage and parasitic
> capacitance will cause trouble. The diodes across
> the inputs rely on the opamp being fast enough to make the negative input
> follow the positive input... not always true with fast moving cignals.
>
> Beginning to wonder if this whole input protection idea isn't more trouble
> than it's worth at best and at worst - merely placebo?
>
> I know there's not going to be a one size fits all solution... but I
> thought I'd gotten 'near enough' with this current schematic.
>
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