Vermes
Advanced Member level 4
It is a low power single ended tube amplifier of own construction. The device was based on Soviet tubes: 6n2p in preamplifier and 2x 6p14p in the power amplifier. The amplifier operates in triode mode. Transformers tg2,5/1/666 were used in this project. The amplifier was assumed to have approximately 2W per channel. Transformer TS50.
Specification:
- PRI: 230
- Sec:
- 220V/120mA
- 6,3V/2,5A
Schematic:
Housing and chassis:
Housing was adapted to the device by cutting out the front and sanding, then painted with a lacquer. Front and top are made of 2mm aluminum sheet, also sanded and painted with a golden spray. Speakers terminal, IEC socket and a fuse are on the back. On the front, you can see input, volume control, anode voltage (blue switch) and glow (red switch).
Power supply:
The power supply was designed on a PCB. At the input behind the first capacitor there is about 305V.
Filtering consists of:
- 3x 100uF/400V
- 2x 47uF/400V
- 1x 100nF/400V
- 1x 470nF/400V
- resistors 5W
- bridge 6A
There is also a safety button, which is a plus shorted to the ground by 110kR. When you want to change anything, just discharge the capacitors using that.
Assembly and run:
Front is connected to the ground via a socket. Top, when it is screwed, shorts to the front and shields the whole device.
Glow is symmetrized to the ground via 100ohm resistors.
Link to original thread - Wzmacniacz lampowy małej mocy