As local sale of tubes is not satisfactory for me, I decided to build new, full, power amplifier from scraps and surplus components. It will we classic tube amp with double tubes on the output. Why this type? Because it uses lots of tubes and I have transformers.
The main component for tube amp is cool case. Tube holder places are made from old computer case. I used some “branded” and very old computer, so the steel is solid compared to new Chinese made computer cases. The round holes are made using step drills on some drilling machine.
The case itself is some 19 inch box from some old communication device. It was some serial switchboard of something. There was lots of these in local scrapyard and I made one major mistake- I didn’t stored more boxes for myself.
In this photo you can see the tubes and PSU installed. Even 75% of tubes are connected to heater. The output stage is made from old classic- 6ÐŸ3Ð¡ (6P3S, EL34). The phase inverter and preamp will use some tubes from 12AX7, 12AU7 or 12AT7 range. As I have lot’s of these pull-outs. The mains transformer is with nominal 100W power. This is not some Chinese Watts or other RMS/SRS Watts used in western sale-market world. Nominal power term was used in Soviet time to describe real power of device. This means, that device can handle such power for infinitive time without any harm. Regularly, this means, that power of the device is 50…150% more powerful than stated.
This is the beginning. The rest will come…