K 8077 noise

I have build k 8077.
All measurements seems to be ok.
When I connect loudspeker to LS- and LS+ I hear a high noise.
Where shall I begin in my trobleshoting?


Can you be more specific on this problem ?
Is this noise present with volume pot turned to zero ?
Is it hum, noise, oscillation ?
Frequency ?
Level ?

Hello again

It is a quite high sound, not brumming, and not depend on volyme-settings.
When I connect line in, I can hear some music…

Is is a high noise