So, this isn't strictly audio-related, but hear me out.   I've gotten sick of having a gajillion wall-warts attached to things attached to or just around my PC, so I've decided to build a tiny little power distribution unit that'll take a laptop power supply in on one side (15VDC @ 6A) and...

I am, for kicks and giggles more than anything, intending to play around with a discrete preamplifier design from 1967 to see how well it may work as a headphone amplifier. I'm replacing the long-obsolete 2N404s with BD140s, and making a few other changes to allow the use of modern parts. One of...

I was reading about biasing opamps into Class-A operation a while ago, and saw some comment somewhere about how some of the more desirable audiophile-approved(TM) opamps couldn't deliver enough current to be of serious interest as Class-A audio amps. That got me thinking... has anyone ever tried...

To be honest, I'm not sure why I'm even bothering posting this, since everyone here seems to have some sort of obscure and irrational objection to powering anything from computer USB power. That said, the idea gets raised fairly often, so... I have designed and tested a USB power supply based...

Yeah, I know the idea of powering a headphone amp off of 5V USB power gets asked all the time, and is inevitably shot down by everyone as useless and impractical. Thing is, I don't necessarily think it is useless. Oh, sure, you can't power even the tiniest tube amp off of USB power, and 5V isn't...

Late last year, a Head-Fi user posted about a $95 tube amp available on eBay. This is pretty much the only reference anywhere on the web to this amp, the "Xiang Rong Audio" XR01 (or XR010, take your pick). As you can see from reading that thread, the amp - as designed - needed some work to be...

Does anyone here have any experience with the USB sound card kit designed by DIYzone, and frequently available cheap on eBay? It looks like it could be interesting, though probably fairly low-fi. I picked one up a while back, and assembled it, but the thing doesn't work; there's a short...

A lot of folks here seem to make use of PCB prototyping services, and I know there are a few "firm favorites" everyone likes to use. I've used BatchPCB in the past, and while their service is high-quality, it's not really that cheap - especially once you start dealing with two or more copies of...