New bi-polar stage output amplifiers with driving high output power for professional loudspeakers without clipping. All have steel reinforced bodies & comprehensive protection circuitry. Efficient stable front-to-rear airflow & dual aluminum extrusion heatsink design with directly mounted output transistors provide reliable no-fault operation & 3 modes: stereo, parallel mono & mono bridge. All have clip & signal LEDs, X-04 has VU-meters. ¼” TRS/XLR balanced inputs & ¼”/3-way binding posts outputs. When driven @ 8W, X-01 can handle 85w RMS, X-02 can take 140w RMS & X-03/X-04 handle 200w RMS. Compact 2U (3U for X-04) amps are a one-time solution.