MTX X504 Aop upgrade ?

[Ground Zero]

Hello

I have bought a MTX amp X504 to put in my car but the sound is really bad not clear and detailled

So i would like to replace the two AOP NJM2904D JRC "dip8" with 2 Aop: OPA2134PA from burr brown

but before can you tell me please if the AOP NJM2904D JRC is good or not?

this is the data sheet

NJM2904D datasheet, NJM2904D datasheets, NJM2904D datenblatt, NJM2904D manual, NJM2904D data sheets, NJM2904D pdf - ALLDATASHEET.COM

this is the datasheet of the aop from burrbrown

OPA2134PA datasheet, OPA2134PA datasheets, OPA2134PA datenblatt, OPA2134PA manual, OPA2134PA data sheets, OPA2134PA pdf - ALLDATASHEET.COM

thanks for your help

[Ground Zero]

and can you tell me please what technical information i must see to choose an AOP to have the better sound?

Thanks