I completed my build: I rebuilt the amp boards with new PCB with improved layout and went back to the original Naim regulator circuit for the power stage. The amp sounds very good and behaves better, see attached scope shots:
20kHz square wave (0.5V input) into 8R and 1uF
20kHz square wave (clipping with 3.5V input) into 8R and 1uF
20kHz square wave (0.5V input) into 8R and 1uF
20kHz square wave (clipping with 3.5V input) into 8R and 1uF
. We don't often see any objective measurements of Naim or related high-end circuits in discussion here.Thanks Ian! I have only a digital scope and a cheap DDS signal generator: what else can I measure with that?
Hello jpk73!
i see your new amp is very very stable on square wave it's impressive.
when I improved the stability of my old amplifier on its regulation and amplification board I also found an audible improvement especially with the improvement of the power supply board in fact.
As for objective measurements, I now have new very low distortion loudspeakers and I have done some ABX tests (so on the whole chain and not just the amplifier)
I passed the test at 0.1% distortion at 19/20 which means that the whole hi-fi system is below, a NAP250 being at 0.03% I think my version must be close to that even if I don't have a distortion meter.
https://www.audiocheck.net/blindtests_index.php
i see your new amp is very very stable on square wave it's impressive.
when I improved the stability of my old amplifier on its regulation and amplification board I also found an audible improvement especially with the improvement of the power supply board in fact.
As for objective measurements, I now have new very low distortion loudspeakers and I have done some ABX tests (so on the whole chain and not just the amplifier)
I passed the test at 0.1% distortion at 19/20 which means that the whole hi-fi system is below, a NAP250 being at 0.03% I think my version must be close to that even if I don't have a distortion meter.
https://www.audiocheck.net/blindtests_index.php
Thanks to Cristobool's courtesy, I'm also building this amplifier using the 2.3 boards. I figured that since I've benefited from my colleague's work, I should also contribute something. I have designed NCC200 boards that match the dimensions of Cristobool's boards.
Also you can find a picture of my amplifier (still under construction) 😉
Also you can find a picture of my amplifier (still under construction) 😉
Attachments
Yes, I'd already seen your thread about regulators!
There's no consensus on whether this improves quality; I've never been able to find a clear and convincing demonstration one way or the other.
So I tend to rely on my own experience and, quite simply, on what Naim Audio does.
I've since designed and built a new NAP 250 clone (with the help and work of other forum members) that I'm finally fully satisfied with. I can say that this time its design is truly accomplished and that I've corrected the mistakes I made on the previous ones.
There's no consensus on whether this improves quality; I've never been able to find a clear and convincing demonstration one way or the other.
So I tend to rely on my own experience and, quite simply, on what Naim Audio does.
I've since designed and built a new NAP 250 clone (with the help and work of other forum members) that I'm finally fully satisfied with. I can say that this time its design is truly accomplished and that I've corrected the mistakes I made on the previous ones.