Over the Christmas time, started servicing another head unit.

The owner mentioned that he observed significant imbalance between the L and R channels.
He had to turn the balance knob like 80% more towards the R-side.

On the bench with oscilloscope, while the RR and RL channels were pretty much even, for the Front channels, it was actually the FR at much higher output than the FL.
So, opposite of what the owner said.

Then, connecting to the real Bose AMP and speaker cone, to my ear, all 4ch sounded evenly when tested one at a time so not conclusive.




Probably one of the most clean face plate that I have ever seen for this year model.
Almost no scratch or faded white text.







The usual capacitor leakage but since I couldn’t recreate the same issue that the owner mentioned, going to replace these capacitors on the tone/balance control board as well.


The AMP at the R-door is believed to be the one that was previously serviced by someone using the wrong parts.

Later, I refurbished it but had to replace so many components.

I will be testing this head unit using my NSX at the end of the service to put some mileage.




More than 7 months ago, started testing the spare AMPs using my NSX.

All 3 x speaker boxes have them.

Already covered more than 2,500miles and went through scorching hot summer and recent freezing cold weather.

I would rather replace the owner’s R-door AMP with my spare one installed at the same side so that when the owner puts everything back in place,
exactly the same setup between the audio head unit and the R-door AMP will be established.

More to follow.


Kaz