Did you add resistive loading on the input? Check to make sure you have about 50k ohms on the input. Running this low can kill highs.
Normally, the Bugle is a wideband design with a -3dB point well past 100kHz. There should be no audible rolloff of treble.
It's possible some of the resistors were put in the wrong place. Or maybe you used other caps? Check to make sure they are 0.22uF and 0.01uF.