Originally Posted by Timestoo
Actually from that, I discovered my true passion of my life, electronics. I quit music in 79 and went on had a full career in electronic engineer until I retired. Then I went in full circle and designed/built 2 guitar amps. This time in the right way using MOSFET to do the power scaling. Both have channel switching. BUT, I really are not interested in playing anymore, it's a waste to design guitar amps. One also sit in the shed. So I switch to design hifi power amps. Hey, it's better than doing crossword puzzles!!! This keeps my mind active.
Alan, it's funny how one can spend their whole life trying to find something that lights up their soul. You put a smile on my face when I read this post because I believe life's true riches has very little to do with money. Also, you are very modest...I could kick back and listen to you play, anytime!
Thanks to all here for the amazing help and I will do the tests/trials and post my findings. This has turned into a major (for me) revamping of my room but I'm getting it on.
Thanks for the complement. I believe in finding a career that I truly have a passion in it. 8 hours a day, 40hr. a week is too much if I don't enjoy what I am doing. I don't choose career for the money. But if one really like what he/she is doing, money will come. I did look very hard at the time. I had a Chemistry degree, but I hate it, I rather worked as pizza delivery for a while looking for my true passion. What I did not expect was I gave up music because it took too much time away from my longing to study electronics. I just woke up one day, packed my guitar up, never even open the case for a few years in 1979.
I never believe in getting a job because it pays good. I teach my grand kids to look for their passion, don't worry about going into a career for the money. If you have passion, you'll be good at it, and you'll be reward for it.
One important thing, this is just talking out loud. I have schematic of Classe 150, 300, 301, 400 and 401. BUT I could not find yours. I read their service manual, it's not well written, but I think they adjust the bias too low. My question to you is after your amp is on for like 1/2hr., how warm the heatsink? If it is barely warm, you are under bias even it might be adjusted to spec.
To adjust the bias, you adjust VR102 if you know some electronics. My experience is you measure ( in case of the others R1 to R6) and average should be about 30mV. This is where I find the sweetest sound. Believe me, the bias really really make a difference.
I don't want to encourage you to stick your hands into the amp, I don't want to be responsible if anything happens. Just want to have you at least check how hot is the heatsink. Nelson Pass gave a very good advice to people, you adjust and feel the heatsink after 30minutes of warmup. If you can hold onto the heatsink with your hands for at lest 15 seconds, it's not too hot. We can talk more after you respond.