11 Jan '15, 5pm

From the archive: #Arduino based tube stereo preamp project

From the archive: #Arduino based tube stereo preamp project

The 12B4 triode was originally designed to be used in televisions as a vertical deflection amplifier. New-old-stock (NOS) 12B4s still exist. They can be purchased from most US tube resellers. However, a European equivalent doesn’t exist. The 12B4 works well in preamplifiers as a one-tube solution, having both high input impedance and low output impedance, without need for an output transformer. An audio circuit can then be distilled down to a simple circuit with few parts consisting of a volume potentiometer and a grounded cathode gain stage. The 12B4 has about 23-dB gain, which is more than is needed. This extra gain is used as feedback to the grid, in what is often referred to as an anode follower circuit. The noise, distortion, and output impedance are reduced (see Figure 3). Using relays controlled by the Arduino enables switching between two feedback amounts for adjus...

Full article: http://circuitcellar.com/cc-blog/arduino-based-tube-stere...

Tweets

Stereo Audio on a PIC32

Stereo Audio on a PIC32

hackaday.com 12 Jan '15, 3am

The PIC microcontrollers are powerful little devices, and [Tahmid] is certainly pushing the envelope of what these integra...

From the archive: #DIY #Arduino based ECG system

From the archive: #DIY #Arduino based ECG system

circuitcellar.com 15 Jan '15, 5pm

Cornell University students Sean Hubber and Crystal Lu built an Arduino -based electrocardiography (ECG) system that enabl...

SAfrica awards solar thermal power project to consortium: Johannesburg, South Africa (SPX) Jan 11, 2015 The S...

SAfrica awards solar thermal power project to c...

solardaily.com 11 Jan '15, 2am

The South Africa Department of Energy (DOE) awarded preferred bidder status for a 100 megawatt (MW) Concentrating Solar Po...