D3A phono complete (almost !!)

This project took the longest time to complete, but it is finally done (almost).Still need to tweak for the input impedance - right now the default loading is at 50K. Maybe use a linear pot like Edwin did on his initial phono stage designs. My initial impressions are that it is quiet for a tube phono stage (no low-freq hum). It is also detailed sounding maybe a littled tipped to the high frequency, but I think I might be able to workaround with changing the loading impedance. This project is collaborative effort on diyaudio.com - the shunt regulated high voltage power supply is designed by Salas in Greece, the phono stage is designed by Andrea Ciuffolli in Italy and the PC boards designed by Quanghao in Vietnam. I'm using an enclosure from par-metal - nothing fancy but does the job for this project.













Some features I need to incorporate in the future :

1. Toggle Switch MM & MC
2. Install Altec 15095A
3. Loading option using a Dual Linear 100K Pot or Stepped Attenuator
4. Re-orient the phono board