Hi Brian,
Thank you for your post, and welcome to our little audio coven!
You have good equipment. Both Linsley Hood and Duncan have been profound influences on my thinking over the years, I actually use JLH's concept of phase lead in the AKSA, so I know pretty much where you are coming from. I'm also quite confident you would be very pleased with an AKSA.
Firstly, at 52 (I'm 54!) you will certainly notice the difference between stock, Nirvana and Nirvana Plus. Until his passing at 86 recently, a neighbour and good friend could pick these differences with ease. There appears to be a consensus at Audio Circle now after a year of so of the 100W N+, and subjectively I'd place the stocker at 7/10, the Nirvana at 8/10, and the Nirvana Plus at 9.2/10, with some suggesting even more for the N+. The downside is that the N+ uses Black Gate capacitors, which take many hours - up to 150 - to break in, and during this time some there are some quite strange sounds, taxing your patience considerably.
One of the biggest issues of all in reproduced music is the notion of intermodulation distortion; the muddle which results with very busy, often orchestral music, when the going gets rough. If you listen at high volume to classical music, and your speakers actually seem of average efficiency, around 88dB/W/m (this assumes 1W, not 8W!), then yes, the 100W is for you. One of the benefits of the larger power is that dynamics are extended, and the sense of ease and spaciousness is much enhanced. These 'improvements' come with almost imperceptible loss of detail because of the doubled output stage and beefier drive circuitry, but in practice, you do not notice it because the scale of the sound, the increased headroom and absence of intermodulation effects are deeply impressive. It took about 5 months to achieve the N+ for the 100W AKSA; it was a constant, tiresome round of component selection and dimensioning which almost wore me out, but finally I pushed on within spitting distance of the 55N+ and was most relieved, I can tell you. And while it may seem expensive at first sight, on listening, particularly over an extended period, you soon realize it's one of the best sounds you've ever heard.
All the AKSA amps (at this stage!) are Class AB, and the 100W quiescent is just 58mA, giving a power consumption at idle of 25W for both channels, low enough to leave it on pretty much permanently.
I hope this is helpful, and my thanks to Peter, Carl and Mal for their kind comments. Much appreciated!
Cheers,
Hugh
