Yes I have the tutorial and I remembered reading about that. I'm just fixing amplifiers because I enjoy working on electronics and I’m retired so I’m bored. I started about 2 months ago and have 7 out of 10 fixed. You and your tutorial helped me a lot. I buy broken amps for 20 or so and I think I will sell them for cheap and get my 20 back to buy more and donate the rest to St. Jude.