Gentlemen, I would like to comment here.
The schematic that was posted on another forum is not a reverse engineering of the pre-production LL. It is a 1-2 year old schematic that I probably shared with one or two people as I was thinking about how to do a stat amp. I don't have any idea how the schematic became available since I did not provide it to the individual who posted it.
As for the 323.
I have never seen a schematic of the 323 until the one that was posted following the post of the earlier "LL" schematic on the other forum.
But, if you think about this for a minute or two you will remember that there have not been a vast number of radically new designs in analog amps. Some, but not every amp that is released by all the manufactureres in the world is somehow a totally new design, totally different from anything that has preceded it (until class D).
Nearly every analog amp uses various common subcircuits: diff amps, current sources, current mirrors, vbe multipliers, gain stages of various types, followers, current stealers, cascodes, etc. The evolution of analog amps has frequently been where someone takes these basic elements, uses them in a way similar to prior art, but does something different in one part of the circuit and gets a better result. For example, there have probably been a "billion" discrete opamp power amps built in the last 4 decades. They are all similar, but many are different through one tweak or another another, with better or worse results.
I could argue that any amp that uses these basic building blocks is simply a retread of every amp that came before. In some sense this is true. After all, what's new in that amp that we haven't seen before? It has a diff amp front end, a gain stage, followers for the output, it therefore must be a copy of a previous amp. Every stat amp whose schematic I have seen uses these basic building blocks. So what's new? Yet, I think, for example, that the KGSS is a very clever design. Always have. It deserves its reputation. But it uses all of these subcircuits.
So I don't get what the big huff is about. The LL is similar to stat amps that have preceded it. How could it not be, it uses all the same building blocks? There are only a few ways to build a stat amp with currently available components and once you choose a way, there is prior art.
OTOH, I think that the LL is different enough to be a worthy addition to the marketplace and will, hopefully, suit some people better than the other offerings that are available. It has 400V rails and can swing as much voltage as other amps in that class.
But, let us not lead others inadvertently into the thought that somehow the LL is just a ripoff of a prior stat amp. In that case all the stat amps are ripoffs to some degree or another, except for the very first one. But, I don't think this way (unless someone has seen the prior art and literally copies it). I just see amps that are variations of one kind or another trying to find a place with customers who like them. And not find a place with those who don't.
Finally, I am about to finish one or two more pre-production LLs that will look exactly like the real production amp and whose PS and amp sections will be identical to the production amp. I have been planning to post interior pics of this amp on the website when I have them. I still plan to.
