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

There’s a mystique among both audiophiles and musicians about vacuum technology, thus having a tube amp still carries a bit of a cachet. New ones can be bought for eye-watering prices and old ones can ...

You can use three discrete transistors to build an operational amplifier with an open-loop gain greater than 1 million (Figure 1). You bias the output at approximately one-half the supply voltage ...

I got to thinking about this after seeing the Aopen tube MB. After that I started looking at building tube amp threads there was 1 or 2. What I gathered was that tube amps put out good sound. I still ...