A Simple, 5W, 4-Tube Hi-fi Single-Ended Triode Amplifier

Sounds cool, doesn’t it? Here’s a chance to build your own amplifier – a simple design with outstanding sound quality. We are offering the schematic absolutely free, and we think you will be surprised at just how good the sound quality of this amp is.   Let’s Go Inside There are four tubes, two per … More A Simple, 5W, 4-Tube Hi-fi Single-Ended Triode Amplifier

The JJ ECC99 Tube

Now here’s a current-make tube well worth becoming acquainted with! While I have heard the excellent sound of the Sovtek and the Electro-Harmonix 6H30PI “super-tube,” I must confess that, while as excellent as they are, they paled in comparison to the JJ Electronics ECC99. And no, we are not affiliated with JJ Electronics in any … More The JJ ECC99 Tube

On Capacitors: Film

As stated before, we have made some mighty interesting discoveries about film capacitors. To begin, we’ll discuss capacitor values in the circuit. Because a capacitor-resistor network, such as is commonly used in tube amplifiers, is a high-pass filter, it follows that there is a certain minimum capacitor value that can be used before the bass … More On Capacitors: Film

OTLs and Beyond

I experimented with a push-pull triode-connected 1625 amplifier, and learned much from that. I moved on to using a 6L6GB instead of the 1625. It was during this project that I accidentally made what proved to be an important discovery when it comes to building better tube amplifiers — the coupling capacitor size is more … More OTLs and Beyond