Phono tube amplifier
This is the first design of my tube phono stage. I worked on a second design and finished the PSU. I’ve build an external PSU and removed the parts from the chassis cause the transformer injected hum into my circuit. When I’ve moved to my new flat, I’ll test different Phono stage designs and rebuild the amp part.
New power supply for my valve amplifier
Target: No oscillation on lower frequencies (pumping speaker) and adjustable output.
First Image: Construction: ~400VDC to ~310VDC.
Second Image: Testing with valve amplifier
Final Version of the power supply: Output Voltage ist 305.5V DC Stable. Changes in the base voltage can drive the voltage up or down a little, but only by 0.025V. Voltage filtering at Input: 10 x 68uF + 2x 47uF + 2 x 20H inductor. Regulation is done by FET with temperature compensating precision reference, protection from shorten circuit / load faults. No hum or fuzz can be measured in the anode voltage.