Feb 12, 2021
I did recheck the bias on the transistor and, somehow, it was at 35 mV. It is way to high as you recommend a 6 mV. The only logical reason I foresee is that day, the tip of my DMM were not clean. I mean, I remember having check for 6mv not 35mv. Anyway, now everything is back together and I’m so please with it. I also had the chance to test a Tandberg 3012-A integrated amplifier. As per the research I have done, this unit is suppose to provide a good sound and it is intend to be in the upper mid-fi. What a deception compare to what I have built with the LM60. My current setup is by far way over it in terms of sound clarity, opening and precision. As a mentioned in previous email, I have enclosed pictures of my integrated amplifier.
Some technical data: It is a fully integrated system controlled by an Arduino to provide LCD text, remote control, optical encoder reading, softstart delay and controlling the PGA2320. All the source are buffered through a dual mono OPA827 and then goes in the PGA2320. The main transfo is a 350VA and its outputs are rectified through 8 MUR860 diodes. Then everything is smooth through 40,000uF capacitors per rail. That is more than enough and I can tell you my amplifier never suffer from lack of power.
I’m happy being able to close this project and your support was on the top end. You are always there when we need you and you provide more support than most company will do for their product. Highly recommend you and your product to whoever who wants to DIY amplifier.
Thank you so much again.