The Seeburg DS160 amplifier makes a special hiss for about 15 seconds
every time a new record starts playing. There is a hiss, even if the
needle doesn't even hit the disc. If the needle is raised to the
beginning of the record after the record has played for a while, the
hissing will no longer be heard. In other words, it seems that the
hissing somehow comes after the change in the state of the mute relay.
New capacitors have been replaced in the amplifier and it works fine
after the initial 15 second hiss has subsided. Where could the fault
be?