My BA-3, my first try at building something like this. Made mistakes, rebuilt parts of this over and over, many things I'd do differently next time, and not as clean as I'd hoped for, but I'm pretty happy with it. The transistor/heatsink placement on the front end eliminates any thermal constraints, and makes it much easier to access the test points on the board. I used the Cardas CPBP binding posts which are fantastic. A little spendy maybe, but they provide a much quicker and more secure connection for spades than traditional posts. After many months I've finally got the physical build and the bias and harmonic balance dialed in to a place where I'm happy. I measured 36W before clipping into 8 ohms, which I'm quite pleased with. Thanks to everyone who answered my endless questions. You know who you are. If you're ever in Sacramento, I'll buy you a case of beer.
Good evening to all the friends of the forum, it is my first post and also thanks to all of you who have returned my passion for self-construction of audio components.
After several months of finding both the material and the time I was able to finish the electronic and good mechanical part of my amplifier.
It is a particular project because there are 2 class A amplifiers in a single self-built chassy, a 5 + 5w powered by a 24v switching power supply and a pair of 60 + 60w aleph 5 clones powered by a linear power supply with a toroidal built specifically for have the two channels completely separate.
The two amplifiers are exchanged both in input and output with a series of relays that also act as protection for the speakers, in order to manage energy consumption based on use and listening volume.
I still have to finish the chassy with wooden sides and an aluminum bottom.
Sorry for my English, I use Google Translate, I'm an Italian & Tuscuany D.O.C. !!
I'm committing a mortal sin, I built a Pass class A/B amp, the AB100. I had a Proton D1200 release the magic smoke so I gutted it and used the case and part of the board containing the meter drivers. Went a little overboard with an 800VA transformer, it does weight just a little. Cable management leaves a little to be desired, but sounds awesome.
Thanks for the comments, it took a long time to find mosfets with very similar characteristics as well.
This is a photo of the heatsink with the newly fitted power amplifiers, the heatsink and a 7kg aluminum block of an inverter.