What's the big deal?
It's exactly the same as claiming that a different "plastic" in an exact same value capacitor can be heard.
Or silver wire instead of copper wire in a transformer.
His only sin is that he charges too little and he didn't have "Sublime Intergalactic Audio Magazine" write a glowing review.
What about CD? Perfect sound forever! The ultimate scam perpetrated by Phillips and Sony! Assisted by Herbert von Karajan...."All else is gaslight!" yeah right.
Different 'plastics' or dielectrics in exact the same value capacitors can lead to measurable differences, so no snake oil here.
Think this discussion is in the wrong section... more like a Lounge discussion, definitely not Solid State...??
The Altmann Tube-o-lator lacquer is an overtone-filter coating-compound for plastic semiconductor packages.
The ALTMANN “TUBE-O-LATOR" lacquer is applied only on the top surface of plastic semiconductor packages of AD-converter-chips, DA-converter-chips, OP-amps and discrete transistors.
Important: Always coat the complete top surface of a device. Do not partially coat a surface, else you may end up in a mess of non-correlated overtones, and the result will not sound as intended.
Attention: Experience has shown, that power transistors in certain circuit topologies CAN over-react to Altmann “Tube-o-lator" lacquer. Over-reaction will lead to a dumb sound (that will make you feel sick), because too many overtones are filtered.