Most normal amplifiers will not like to see the 0.75 ohm load. Interestingly, in my system, I do not require any voltage gain in the power amp because of the low impedance load doesn’t require large voltage swings to generate high sound pressure levels. I just use a source follower mosfet in class A.. Both my phono stage and my Altmann DAC can provide more than enough signal swing for the levels I use when listening. I use an LDR volume control between the two signal sources and the mosfet. The forward path is so simple and amazingly transparent because of the simplicity. The power amp circuit is :-http://i700.photobucket.com/albums/ww7/paulhynes/SE1.jpg
The baffle is 2 metres high and 400mm wide. The drivers are offset from centre. There is another ladder frame behind the baffle arranged at 90 degrees as shown in :-http://i700.photobucket.com/albums/ww7/paulhynes/Picture039.jpg
The frames are constructed from aluminium extrusions used for constructing exhibition stands. I had heavy-duty spikes turned from brass bar to fit the ends of the extrusion so a firm coupling to the floor is possible. The centre of gravity is a little too forward with all the heavy drive units on the front face, so I have wired the back frame to the wall behind via a heavy duty steel cable to prevent any accidents if anyone walks into the frames while dancing to the music. This is necessary because the whole assembly is very heavy and it could hurt someone if it fell on them. I keep thinking I should re-design the frame for more stability but this year has been a busy one. Maybe I will get around to this next year.