Does This MARANTZ 2250B Still Make 50 RMS Watts Per Channel? A Pre-Restoration Benchmark

What tools do I use? https://youtu.be/MLK649c1_fM Before I restore this receiver, I wanted to check to see what kind of condition the power amplifiers were in. As it turns out, they were actually quite healthy! When the restoration is done, I will compare new power figures to the ones seen in this video. I will also take a recording of some music playback through a dedicated microphone to see if there are any noticeable sonic differences before and after.