int amp for naim cd5x

recently purchased a naim cd5x cd player. hooked it up to a ps audio gcc-100 int amp. very dissapointed in the sound quality so far. music sounds congested with little soundstage. have tried various cables even a din to rca hookup. i then tried it out on a borrowed musical fidelity x-150 int amp and got much improved sound quality.
can anyone recomend an integrated amp tube or ss that would match up well with this cd player or recomend a cd player that would match up with my ps audio amp. dont know which component to keep and work around.