I have a full sized cost no object build of a JLH69 with fully regulated PSU + PEH169 caps. Very nice and not to be underestimated into Klipsch Heritage speakers. Sounds so ’right’ and one of my favourite amps.
can‘t for the life of me see how those small Chinese copies could possibly function with those tiny heatsinks - unless they run the output transistors below spec. They need a large surface area.