[Phil Allison[_4_]]

Scott Dorsey wrote:



Most of it is common knowledge but some of it (like phantom fault protection)
really isn't very well-known in the industry at all.


** Not in my experience.

A transformerless pre-amp that had no protection from phantom voltage accidents would soon be toast.

Most only have a couple of 1 amp diodes to stop the input transistors from being reverse biased ( C-E or B-E ) by a short on the signal line when the phantom supply is on - but that is all you need in practice.

What seems to be true, however, is that single chip mic pre-amps ( eg Analog Devices SSM2017 ) need more elaborate protection.


..... Phil