Breakthroughs, discoveries, and DIY tips sent six days a week. Terms of Service and Privacy Policy. Half a century ago, vacuum tubes were very common in audio ...

[Simon] wrote in to tell us about a headphone tube amp that he just built. It is based on schematics at diyaudioprojects.com that were actually featured on Hackaday in the past. [Simon’s] design adds ...

If you’re doing any serious work with microphones, you’ll typically find yourself in want of a dedicated preamp. [ojg] needed just such a thing for acoustic measurement duties, and set about working ...