The Caged Frog II-- A Pentode Based Differential Transconductance Amplifier for Headphones

Caged Frog ][

I really like transconductance amps for driving headphones. The first one I built, the Caged Frog, has remained a favorite of mine. Even the Baby Frog is great for what it is. But, since I have a definite preference these days for differential amps, the next obvious thing to do was make a differential gm amp.

The Baby Frog -- A MOSFET Based Single Ended Transconductance Amplifier for Headphones

As I mentioned in the article about the Caged Frog pentode based transconductance amplifier, in a lot of ways, a pentode is pretty similar to a depletion mode MOSFET.