Onboard Headphone Amp for Active Basses
This is a bit of a misunderstood overachiever. I designed it out of frustration with a Vox AmPlug Bass, which I hated intensely. It was noisy, sounded like dog farts, and couldn't get loud enough without nasty clipping. I sold the AmPlug as soon as I made the HeadAmp. There was no contest.
I can plug headphones straight into my bass and start practicing immediately, with great, loud sound. It's smart enough to switch on the bass's other active electronics (EQ/preamp) by just plugging in the headphones (you'd normally have to plug in a guitar cable to "turn on" the bass). Conversely, when using the bass without headphones, it turns itself off so it won't waste battery power.
But wait, there's more. It also has a stereo auxiliary input for playing along some funky music, and really sounds like a boutique headphone amp. Uses a dual OPA1692 op amp per channel, in a parallel configuration.
I seem to be the only person in the world who is excited about this project. People don't know what they're missing, and I'm OK with that :)
Make Your Own
It's great, I promise!