At the moment I am prototyping a high quality pre-amplifier based around the PGA2310 volume control and an op-amp buffer input with RF filtering. Each channel will be selectable by relay, along with gain adjustment for each channel in terms of increase in dB. Each channel will be assigned a name that can be changed easily in software and stored along with default volume and channel in the on-board EEPROM.
Over the past month or two, I’ve finally fixed up some snags that I had when building the honey badger amplifier. When I first built it, I had a difficult time trying to track down dry joint on one of the start boards - it also had a bad IDC connector delivering power to it. In addition the PSU boards had a fault and needed to be stripped down and moved to new boards.
Over a couple of years, I slowly built out an amplifier based on the DIYaudio honeybadger design. It was an on/off process where I got one part of it working at a time. Starting by building the channels one at a time on a bench PSU. This project consists of a single large transformer and dual mono PSU boards with 20K capacitance on each channel, an Arduino based control board with soft start, overload protection and DC protection.
After a long pause, I've finally started to get back into analog electronics. I'm using the Introduction to Electronics and this blog as a way to help myself back up the curve. Below is my first working circuit, the good old class A amp. Twenty years ago I could have thrown together fairly complex circuits in short order. However, now it takes me a bit longer, after twenty years of C, C++ and Java programming.