Hi, Trimmers in the AF section of a Beomaster 4400 has been replaced and should now be tuned in. In the Service Manual it only says something like “…may be adjusted within the area of 180mV – 2V (for TAPE) but how? Is a random Line signal just to be used or? and why the wide spread in area, what level is the BM4400 trimmed at from factory?
These are designed to be user-adjusted controls in order to match levels between the phono or tape decks and the tuner. There is no “correct” setting as they act as an input-specific volume control ahead of the source selector.