I ordered some Anderson connectors a few days ago and they are supposed to arrive tomorrow.I have the 400hd. I replaced my wires with #4 awg and installed twist welding connectors. I would not splice the wires. Install some Anderson power connectors. A At-5555n ii may be a little too hot for this amp. the recommended power input for this amp is 40 watts peak power.
His amp is class B biased for SSB use.
The builder himself said this amp can be used with the Q5N2 and I was even running it at the same lower 30 watt PEP power level as the Lincoln II+. I based this on the dead key and PEP readings from my Daiwa CN-901HP meter. It's just a bummer that after doing so, the SSB audio output on it is now fuzzy when running barefoot. Oh well, stuff breaks when experimenting and finding limits.