The box pro - Achat 108 sub A troubleshooting

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  • pfl
    Member
    • Jul 2017
    • 10
    • france
    #1

    The box pro - Achat 108 sub A troubleshooting

    Hello Everyone.

    The issue with this audio device was a very low bass level ; tracking the bass signal path on the preamp module i discovered a missing component (resistor R98) on the inverting input of op. amp U14 (allegedly active low pass filter) (see picture).
    I put a 1k resistor but now R/L passive speakers sound level is too low compared with bass level ; i guess resistor value is wrong

    Can someone tells me what's the correct value of R98 on preamp pcb
    or
    can someone provide me with schematics / service manual

    Thanks
    pierre
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      The issue with this audio device was a very low bass level ; tracking the bass signal path on the preamp module i discovered a missing component (resistor R98) on the inverting input of op. amp U14 (allegedly active low pass filter) (see picture).
      I put a 1k resistor but now R/L passive speakers sound level is too low compared with bass level ; i guess resistor value is wrong

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