random, idling...

 

 I just stumbled across this.  I knew the brand, but not this product.  In 1975, the Audio Research D-150 was one of the world's finest amplifiers from 1975, and looks like a lab instrument, not a piece of HiFi kit. 

 150 watts per channel of pure Class A power.  (I believe, as I couldn't find circuit topology, but power consumption supports the theory)  It weighs 115 lbs, 30 of which is the massive power transformer, and if you can find one for sale (usually because someone died) it will set you back in the neighborhood of $25,000. O_O But unless someone dropped it, it's guaranteed to be working fine without a tech even looking at it.  These things were built without compromise, as was everything from Audio Research.

 I only posted the thing for that astonishing front panel.  I think only one person I know might be in that market, and this isn't to his tastes.