The Russian made Voskhod 6H23 Rocket Logo is the best tube for this amp period. Friend of mine got these for his Pathos and flipped out at the improvement.
Pathos Classic Mk 3 Problem, Please Help
Pathos Classic MkIII left channel goes dead, just a very light hum, after ten mins of use on all inputs, then powers back up fine after restart for 10 more mins. Unit worked fine for me then took a 2000 mile road trip boxed in the back seat of a car to the new owner's house. This never happened before. Any ideas would be greatly appreciated. Thanks.