Kaz-kzukNA1
27-03-2025, 03:53 PM
As in the recent Gauge Cluster service thread, working on many electronics components in parallel with servicing another NSX.
3 x Bose AMPs were delivered from another garage.
I've refurbished the OEM audio head unit for the owner a while ago but the garage reported that there were no sound from one of the door speaker.
After some discussion with the owner including the aftermarket route, he decided to have OEM AMPs refurbished.
I always mention the following whenever I get the question about the ICE devices.
All Bose AMP would fail sooner or later due to the capacitor leakage.
These days, you can get aftermarket Class D AMP at very reasonable price.
Aftermarket ones are not tuned/EQ to NSX cabin and if using OEM Bose speaker cone, you must select the ones that can drive low impedance of Bose speakers.
For this reason, I prefer keeping the OEM Bose AMP as long as possible.
I'm not an audio guru so not someone who is willing to spend £1,000s on ICE.
If you go down the aftermarket route, you can get reasonably priced DSP EQ, etc and customise the sound to your taste.
Everyone has different hearing sensitivity over frequency range.
And of course, it's up to one's taste on how to tune the sound output.
For my ear, taste and the audio frequency sensitivity, I'm happy with the OEM Bose setup combined with the CD changer emulator when everything is working in a way they were designed.
In fact, I'm quite impressed with the sound quality of this OEM ICE system considering it was designed in the '80s so again, another reason why I would love to keep the OEM system.
After receiving the package, placed each AMP on the bench system.
One of the door AMP showed good gain control but bit of cracking signal.
The gain control on the other door AMP and the passenger footwell one was both muted and almost no signal output.
Thus this was the reason why there was no sound from one of the door.
By the way, as mentioned in recent audio head unit thread, you cant measure the sound level between R & L channels unless you measure all 4ch separately one at a time.
You are most likely feel that the L-side is always louder than the R-side.
https://lh3.googleusercontent.com/pw/AP1GczM2Ml7mCAgRY-pXXWSNWqKUj7J23duimByzr70oQA-sxiN9cPO5HVp9Jvv_wplPGmJZlizddL1x55NoSKIXJQBVaY2Sr QKlR1RK0olvOMyDvMxNBot1cnAOfKsdFA03JCv0_WMO6jiV8lO D_qATe9Q8ug=w1080-h810-s-no?authuser=0
https://lh3.googleusercontent.com/pw/AP1GczOi7tgb01PWVB12uF2qJrKEzcVChxvSuvYit3GcL-Cr5sii6JaYLGa-fZ79PDdchX5CpczbSbhHP300jFww-A5wTjQV4b-ZU2_m1K2a5CCMhdwawr_wMrZuIWWzBel9uk8lV733yP8v1cznJ 2dJOvmlCQ=w1080-h810-s-no?authuser=0
https://lh3.googleusercontent.com/pw/AP1GczMTzslgFF0rzV65EIJUIc-QjiJBoTkojkyBA88cqDDFmSoR7RCu93FVrE7gW1hjpuH8PovLG 577zTgoUWiKDGSTMrKiSxC8IPE-Ie4_OF_hnIZdrubySavdIhtzUg729mYB-X8iIRUkM-mfa3IAkPQoOg=w1080-h810-s-no?authuser=0
Now that the problem was re-created, started removing the hot melt glue and the leaky capacitors.
All of them were from the later spec models and to my surprise, the worst leakage was on the door AMP that showed good gain control.
https://lh3.googleusercontent.com/pw/AP1GczNzUb2VaaD0u21Z9Y6WG_9FML5llO2Eu0eryZM7orevd2 X4VJsjZcOO9ACemIg9zIEDKwoO-Fc_x9UR87aSXGhzoMFYUizyy4WS23rQo6-RaIvQHsWxEZhfcAqh64b-I6BRsGuQVq1XriFl49r7QIFKRQ=w1080-h810-s-no?authuser=0
At the end, had to remove the choke coil and scrape off contaminated area.
All boards showed weak connection at some of the soldering joints so re-soldered many points.
Replaced the caps, repaired the damaged tracks and quick bench check before applying the conformal coating,
All voltage level measured at each pins at the Bose in-house ICs.
Confirmed all of them at the expected level including the gain control/mute terminal.
https://lh3.googleusercontent.com/pw/AP1GczP18ofXiNwzzs5Ri6k7UIhAqj3IISC_3rMY4ti_5l_i6n 9_5ctyGgPLeg9hGQ-e4tEMJaUW7GRekd5YON03I_0XXUBw9gMbTQwGTHjhcUszAzttp 3Ec8YEfIX9i7nOZFb14hqvkBI0YkP1BqtuBIYFsEw=w1080-h810-s-no?authuser=0
https://lh3.googleusercontent.com/pw/AP1GczMEtDGtxzhK1mySk2MFHFHFDQCgqKVadJKmDkml4bl5pN tC7GvqX5SRWFZrGe_EDeNU1jxF8BjTnK2jb2cfWcncC_Cn4laV RFeayF76WyxrSbKhk-SsoOkMRXIEyBcm35jELTHUDVx8V0vqsGPYfEcKYQ=w1080-h810-s-no?authuser=0
Applied conformal coating, hot melting glue and thermal transfer compound.
AMPs were delivered without the metal silver cover so I'll send brief instruction to the garage to apply tiny amount on installation.
And already finished the minimum of 24Hr bench testing with 2 x thermal shock sequences while applying so many EMI right next to the AMP as well as the signal source using the OEM head unit.
All went fine and ready to be returned.
Thank you for using my service.
Kaz
3 x Bose AMPs were delivered from another garage.
I've refurbished the OEM audio head unit for the owner a while ago but the garage reported that there were no sound from one of the door speaker.
After some discussion with the owner including the aftermarket route, he decided to have OEM AMPs refurbished.
I always mention the following whenever I get the question about the ICE devices.
All Bose AMP would fail sooner or later due to the capacitor leakage.
These days, you can get aftermarket Class D AMP at very reasonable price.
Aftermarket ones are not tuned/EQ to NSX cabin and if using OEM Bose speaker cone, you must select the ones that can drive low impedance of Bose speakers.
For this reason, I prefer keeping the OEM Bose AMP as long as possible.
I'm not an audio guru so not someone who is willing to spend £1,000s on ICE.
If you go down the aftermarket route, you can get reasonably priced DSP EQ, etc and customise the sound to your taste.
Everyone has different hearing sensitivity over frequency range.
And of course, it's up to one's taste on how to tune the sound output.
For my ear, taste and the audio frequency sensitivity, I'm happy with the OEM Bose setup combined with the CD changer emulator when everything is working in a way they were designed.
In fact, I'm quite impressed with the sound quality of this OEM ICE system considering it was designed in the '80s so again, another reason why I would love to keep the OEM system.
After receiving the package, placed each AMP on the bench system.
One of the door AMP showed good gain control but bit of cracking signal.
The gain control on the other door AMP and the passenger footwell one was both muted and almost no signal output.
Thus this was the reason why there was no sound from one of the door.
By the way, as mentioned in recent audio head unit thread, you cant measure the sound level between R & L channels unless you measure all 4ch separately one at a time.
You are most likely feel that the L-side is always louder than the R-side.
https://lh3.googleusercontent.com/pw/AP1GczM2Ml7mCAgRY-pXXWSNWqKUj7J23duimByzr70oQA-sxiN9cPO5HVp9Jvv_wplPGmJZlizddL1x55NoSKIXJQBVaY2Sr QKlR1RK0olvOMyDvMxNBot1cnAOfKsdFA03JCv0_WMO6jiV8lO D_qATe9Q8ug=w1080-h810-s-no?authuser=0
https://lh3.googleusercontent.com/pw/AP1GczOi7tgb01PWVB12uF2qJrKEzcVChxvSuvYit3GcL-Cr5sii6JaYLGa-fZ79PDdchX5CpczbSbhHP300jFww-A5wTjQV4b-ZU2_m1K2a5CCMhdwawr_wMrZuIWWzBel9uk8lV733yP8v1cznJ 2dJOvmlCQ=w1080-h810-s-no?authuser=0
https://lh3.googleusercontent.com/pw/AP1GczMTzslgFF0rzV65EIJUIc-QjiJBoTkojkyBA88cqDDFmSoR7RCu93FVrE7gW1hjpuH8PovLG 577zTgoUWiKDGSTMrKiSxC8IPE-Ie4_OF_hnIZdrubySavdIhtzUg729mYB-X8iIRUkM-mfa3IAkPQoOg=w1080-h810-s-no?authuser=0
Now that the problem was re-created, started removing the hot melt glue and the leaky capacitors.
All of them were from the later spec models and to my surprise, the worst leakage was on the door AMP that showed good gain control.
https://lh3.googleusercontent.com/pw/AP1GczNzUb2VaaD0u21Z9Y6WG_9FML5llO2Eu0eryZM7orevd2 X4VJsjZcOO9ACemIg9zIEDKwoO-Fc_x9UR87aSXGhzoMFYUizyy4WS23rQo6-RaIvQHsWxEZhfcAqh64b-I6BRsGuQVq1XriFl49r7QIFKRQ=w1080-h810-s-no?authuser=0
At the end, had to remove the choke coil and scrape off contaminated area.
All boards showed weak connection at some of the soldering joints so re-soldered many points.
Replaced the caps, repaired the damaged tracks and quick bench check before applying the conformal coating,
All voltage level measured at each pins at the Bose in-house ICs.
Confirmed all of them at the expected level including the gain control/mute terminal.
https://lh3.googleusercontent.com/pw/AP1GczP18ofXiNwzzs5Ri6k7UIhAqj3IISC_3rMY4ti_5l_i6n 9_5ctyGgPLeg9hGQ-e4tEMJaUW7GRekd5YON03I_0XXUBw9gMbTQwGTHjhcUszAzttp 3Ec8YEfIX9i7nOZFb14hqvkBI0YkP1BqtuBIYFsEw=w1080-h810-s-no?authuser=0
https://lh3.googleusercontent.com/pw/AP1GczMEtDGtxzhK1mySk2MFHFHFDQCgqKVadJKmDkml4bl5pN tC7GvqX5SRWFZrGe_EDeNU1jxF8BjTnK2jb2cfWcncC_Cn4laV RFeayF76WyxrSbKhk-SsoOkMRXIEyBcm35jELTHUDVx8V0vqsGPYfEcKYQ=w1080-h810-s-no?authuser=0
Applied conformal coating, hot melting glue and thermal transfer compound.
AMPs were delivered without the metal silver cover so I'll send brief instruction to the garage to apply tiny amount on installation.
And already finished the minimum of 24Hr bench testing with 2 x thermal shock sequences while applying so many EMI right next to the AMP as well as the signal source using the OEM head unit.
All went fine and ready to be returned.
Thank you for using my service.
Kaz