The Onkyo M-504 power amp...is a great amp. It had great reviews and works perfectly..for 20 years. The problem here is it dose not work with a 4 ohm load. Which it was never designed to do i guess. But high end stereo speakers of the time, were not 4 ohm either. Don't fault the amp. It is the best amp Onkyo ever made.
This is nothing but a power amp..hugh, weighs a ton.
Stereo hi end speakers of the time were never 4 ohms. The amp works perfect, with all the others.