[1000mp] FT1000MP M V Field, Audio differance between MAIN and SUB receiver

[f.schwartz1 at chello.nl]

Dear FT1000MP users... question,

Who can explain my loudness difference on the headset output A (3,5mm) between the MAIN and SUB receiver.
Has it something to do with the inrad roofing filter???? 
The audio strength between the MAIN and SUB is substantial! To be frankly annoying.
I checked the little pots underneath the small lid (topcover) but that makes no difference.

During the CQWW SSB contest I used N1MM and CAT interface
 had the REV audio active
 as soon as I clicked the B VFO (sub receiver) the audio strength was approx 3 db more.

But generally the audio from the main receiver has a lower value than the SUB receiver.
In strength about 3 db less, the AF knob position on the main receiver +/- 2 o clock (so almost max)
However the audio sounds okay no clipping or so
 
 so rules out a poor AF headphone amp



The radio a FT1000MP Mark V Field, (1,5 years old)

73 

Frans (PA5CA)