B780 thermal problem

[peterpan55]

Hello, could someone please provide me with information on the solution and modification to the thermal problem of the quiescent current control (transistors Q13 and Q5) in the Revox B780?

[peterpan55]

Hello, I would like to add a small clarification; my question is rather about whether the excessive heating of Q13 and Q5 is normal and its possible solution; for the rest, the equipment works correctly. Thank you for your attention.

[peterpan55]

Can anyone comment on the existing modification of the Revox B780 audio amplifier, (module: 1.780.105.00)?

[peterpan55]

Good morning; I notice that many colleagues stop to read this post about the amplification stage of our beloved Revox B780; I know that there is a modification to solve the problem; it would be appreciated if whoever has the answer would publish it for everyone.

Best regards.