Mukhang may pila na . . . When you have time boss the Aleph X and the A75 class a pass amp also looks good. Maganda dual monobloc config para it can work with my existing shelving ;-)
https://www.passdiy.com/pdf/a75p2.pdf
http://www.facstaff.bucknell.edu/esantane/movies/aleph-x.html
Iirc the Aleph is a balanced amp, which inspired the modular BA series Class A power amps. Otoh, the A75 is quite old but also served as the predecessor of the F series Class A power amps.
Just for clarity, although both BA and F series were centered on DIY, the BA series was tailored for those who liked using balanced amplification while the F series is like a telenovela that took it's journey with the premise that the first Watt, is the most important Watt. Hence, the Firstwatt series was born. Nelson Pass took DIYers on a long journey starting with low wattage series like the F1and F3. The F2, still low powered, is a transconductance or an active current source type of an amp, somewhat unusual but if you know NP, it's no surprise. The F4, otoh, is the mother of all buffers, it's simply an impedance converting power amp, it has no gain, no feedback and requires a pretty high input voltage from a preamp. All these amps showcases the importance, uses, inevitability, and the gritty reality of applying constant current sources in power amplifier design.
The F5 though is the culmination of all these, plus the reality that not everyone is a fullranger, or owns a high sensitivity speaker system. Still, for the power hungry, the F5T was born.
Nelson Pass, in cooperation with diyAudio conducts annual Burning Amp Festival where anyone (kids are welcome) can build their own fleawatt power amp, the Amp Camp Amp. The original idea was to hold a picnic style gathering, but instead of barbeque, you hold a soldering iron and build a fleawatt, current source, Class A power amp, in one sitting, under a tree.