It is a myth that av receivers from the old days were made better. It may be true for the power amplifier section if they are of the class AB type. Other than that, technological advance would have more than offset the old gear's use of less efficient power supplies, more metal, beefier heat sinks instead of temperature controlled fans instead of beefier heat sinks, that translated into heavier weights. As for the pre-amp processor, the gap between the old and new gear is significant, such as DSP processing power, newer HDMI, and better volume control, DAC, OPA ICs.