A schematic of an <a href="https://en.wikipedia.org/wiki/all-pass_filter" class="extiw" title="w:all-pass filter">w:all-pass filter</a> implemented with an <a href="https://en.wikipedia.org/wiki/operational_amplifier" class="extiw" title="w:operational amplifier">w:operational amplifier</a>.
<a href="//commons.wikimedia.org/wiki/User:Foobaz" title="User:Foobaz">Foobaz</a>
2007-05-11
<span class="int-own-work" lang="en">Own work</span>