I have been listening to it for extended sessions - 6hrs with many different tracks. This is a nice amp - best word to describe it is neutral and clear. Very happy with it. Runs fairly cool although with tiny heatsink I have for two channels having small air cooled fans is a must. They are quiet though as very low rpm.
VSSA is my basic design, First One M and First One L are sensible way to the musical heaven.
The only right way to be, maybe someday you'll be grateful to sell First One PCB-s too.
I have heard from others that your version, even simpler without CCS, still sounds fantastic. Transistors are cheap so I figured, why not?
You could do the PeeCeeBee with dead bug P2P even given how simple it is...
Basic VSSA has resistor limited quiescent current injection into input stage which is fine, works stable and proves that this design concept will always deliver, which is good.
There are many feedback paths inside and outside the amp influencing the SQ negatively, the only desired, straight and shortest possible one is from output to negative input, others like via power supply rails, GND loops, acoustic to parts, etc., are all unwanted ones, so we have to avoid them as much as possible. To cut off undesired feedback from PSU rails and GND loops we need to use CCS, shunts, filters ... resulting in high PSRR, hence better SQ.
Main feedback has to be preserved and protected from unwanted influences, because this is the only one which corrects amp to follow the input signal faithfully.
In delicate places delicate solutions have to be implemented, in this case CCS is important as input stage, maybe even more. None of the mentioned CCS's are good enough to play the main role here, picking the best academy award winner is the way to go.
LC doesn't like either one. In my (meager) experience it is a CCS and makes little difference so long as it is adequate in maintaining its characteristics over a fairly wide frequency range. Guess I have tin ears and / or too pedestrian equipment to notice .
A two JFET cascoded self biassed arrangement or one using precision references (thinking of a Walter Jung article) are superior as a CCS, but I prefer to avoid JFETs simply due to decreasing availability in TH parts. If I were to go SMD then the choice widens and the JFET looks appealing again.
The CCS appears to be one of LC's pieces of intellectual property incorporated into his First One. I doubt he will say anything meaningful on the subject.
.A two JFET cascoded self biassed arrangement or one using precision references (thinking of a Walter Jung article) are superior as a CCS, but I prefer to avoid JFETs simply due to decreasing availability in TH parts. If I were to go SMD then the choice widens and the JFET looks appealing again.
The CCS appears to be one of LC's pieces of intellectual property incorporated into his First One. I doubt he will say anything meaningful on the subject.
You are completely wrong here, you don't know anything about the First One schematic, especially not about First One v1.4, count the parts on PCB and you'll see you are very badly informed. Listen to the First One amp or ask honest people who has one what's their opinion, it certainly blows away all amps you've ever owned. And finally please show some respect and don't talk to me in third person.
So what is the CCS architecture you suggest as being "delicate" here? A TL431 shunt?
Mr. jk... obviously has more knowledge about the amplifiers, why not ask him how to make proper amp. I think his good only at copying things..
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