Building guitar amplifier: The amplifier itself
Building Ax84 Hi-Octane is quite easy, because everything is well documented. You can also buy a package containing all the major parts – tubes, transformers, and a chasis to hold it all together. Then all you need to do is carefully follow the documents and assemble the circuit together. All projects are quite simple and with basic soldering knowledge could be accomplished. Although, word of warning, that you must be very careful while testing the amplifier, because of the high voltage (~250V), which can easy turn out lethal.
Since I didn’t want to buy anything off the internet and waste any money on shipping, because I live far away from the United States. I needed to look for alternatives, so I searched local markets and shops for similar parts I could use. Most of the materials I found were produced in Soviet Union, so I used different stuff than in schematics. Like EL84 tube was replaced by 6P14P. The biggest problem was to find the transformers, especially the output transformer. At the end I had to wind the output transformer myself. Yet alterations did not stop there. I also wanted to add a feature that would let me switch between the clean and distorted sound (known as channels). Later on I added spring reverb too.
In the end, I have an amplifier that suits me just fine – sounds wonderful and is versatile (tone wise).
Front panel
Front panel with an On, Standby and a reverb control at the top. 2 pairs of gain and volume controls. Tone – bass, middle, high – pots.
Back panel
Holes on the top for ventilation. Back panel with reverb in/out. Pedal switch. Loudspeaker connector for output. And fuses below.
Next article will be about tubes, what did I use, a little comparison between, other alternatives.
Tags: amplifier, ax84, diy, guitar