The background

Since many years back I make SMD designs at work but I have never before designed any audio with mainly SMD parts. This is my very first audio SMD project. Recently I have updated the design a bit. I have implemented a thing called "multiple feedback". Walt Jung has written an article in the subject.

The article can be found here.

This project is not suitable for a newbeginner, but if you only have a soldering iron with a very fine tip and you don't tremble and have a good pair of tweezers, it shouldn't be any problems to succeed. This amp is not very hard to solder, yes I'm not kidding and it's really cool, not common DIY stuff!

Active elements are AD8610 OPA134 or OPA627 and a buffer BUF634. The operational amplifiers are one of the best in their market segments. The AD8610 is new and very interesting.

The performance is outrageous in headphone amp terms. See the technical data!

My design goal was to make a simple but well balanced amp in terms of component choices and a well-tested topology.