interesting tube amplifier for headphones

@SomeMichGuy i was wondering if you mean that you can build something similar with op amps, with very little soldering or PCB knowledge? maybe a pre-made PCB, 3 op amps, and some resistors and caps?

@pdxlinux Oh, I was just thinking that vacuum tubes preceded solid state devices, and op amps dominated analog circuits after the tubes.

It was a standard part of electrical engineering to understand how to make some basic circuits with op amps, but audio had reference books, magazines, etc.

So there are tons of audio circuits, using analog components, in all kinds of references.

It's a pre-amp, though, right? I'll check again...

The tube is a pre-amp and the op amp is for the amplification. The description provides some of the reasoning; the high frequency behavior is often cited by audiophiles in various contexts (including the sampling rate for CDs).

So this design is intended to be tube + op amp for superior audio quality. I wouldn't second-guess them for $20 - $25.