LSA Voyager GAN Amplifier

Thank you @atmasphere very insightful and this bears out with the Bel Canto e.One ref501S I now own that is equipped with Bruno's  Hypex's NC500 OEM module.Much better design and execution than the NAD.

I am a tube guy that has been playing in the Class D world the last 2 years.

@jerryg123 To my understanding the Purifi modules are not offered with an input buffer/gain stage. To the best of my knowledge, the buyer is expected to install their own. This is one of the reasons you see such variable comments on Bruno's modules- some buyers know how to design a proper input circuit and apparently many do not. I don't know anything about the NAD in particular, never heard it. But I do know that the input circuit has to be really neutral and there are some pretty bad examples out there wired into Bruno's modules. So if I were you I would not take your experience with the NAD as particularly meaningful.

Oh, but jerry, it is my business as I don’t enjoy the constant shilling on what is suppose to be, as I understand it, a hobby site. I don’t come here to be spammed with incessant ads and audio quackery. I haven’t attacked Ric for his opinions, I have questioned the veracity of his outlandish and unsubstantiated claims. I have criticized his business model of constantly promoting his money making "improvements" on a hobby board.

And I don’t come here to be subjected to harassment and childish insults from petulant crybabies ignorant of the technical issues who can’t handle anything but never ending praise for their (poor) audio choices.

I get it, you like the amp, you believe in audio magic. Great! Go enjoy yourself.

I am not interested in saving anyone, least of all you.

@kuribo What did you think of the amp?

@atmasphere 

Great post!

People think air core inductors are the messiah, but they can have serious consequences if not used properly. No doubt a large part of the reason for the "style" of inductor use by professional companies like Purifi/Hypex is the closed magnetic path resulting in little stray magnetic field. Drum core inductors are bad enough, and with an air core, that steel mounting screw, those resistor and capacitor leads, etc. are all now part of your circuit, let alone if a customer decides to use a steel case instead of an aluminum one, I would say very common due to the huge cost differential.

For others, the reason for not using toroids is likely for many practical reasons. To get a specific inductance and saturation point in an inductor of a given size, that requires a specific number of turns and an air gap of a specific size. That is easy with many standard cores, one leg is just ground down typically fractions of a mm. That is very difficult with a toroid, and a side effect is the gap is now exposed (EMI, etc.) For that reason and a host of others including inflexible size/mounting, gapped toroids are rarely used. Most common toroids you see in power supplies / amps (not line/audio frequency transformers) are usually a ferrous powder or some similar magnetic material molded with a binder. The "gap" is distributed throughout the toroid. The problem with these materials is they tend to be pretty lossy at the upper end of their frequency ranges and are not overly linear w.r.t inductance versus current. Some toroids are ferrite, but you are limited purely in turns ratios w.r.t. usage.

p.s. to those who called me an "armchair/wikipedia engineer", this is me having the last laugh.

the Bel Canto e.One ref501S I now own that is equipped with Bruno's  Hypex's NC500 OEM module.

@jerryg123 Just as a FWIW; that suggests that if BelCanto (fun trivia dept.: one of their staff used to work for me...) were to use the Purifi module it would sound very similar to the amp they make now.