Haven't been able to find any info on what improvements Schiit claims for the 'Plus' version.
Also, with the Heresy, Schiit is competing against themselves for the same market space. Seems like that is going to confuse people.
As I write this, Amazon has the Magni 3 (not the new 'Plus') on sale for $74 for Black Friday weekend.
This is from Jason:
The Showdown
The thing is, to have a proper showdown I’d need to have a Magni 3+.
And that, my friends, was a lot more work. Like I said, I knew how to improve Magni 3. It needed a driver stage and some power supply filtering. And, at the same time, it would be smart to include the new matched dual BJTs that we were beginning to use in Nexus™ topology amplifiers—it would reduce the number of packages, and improve performance due to better matching.
Aside: another challenge of discrete design is that the individual transistors vary more than, say, and op-amp (though those vary as well). The design either has to be insensitive to variation (most of what we do) or everything has to be matched (Nexus™).
But even by going to the matched devices, I was left with a very complicated amp. Magni 3+, with the addition of a driver stage, had morphed into a tiny Vidar—literally. No kidding, the topology is that close. We even had to add a Vbe multiplier to get control of bias (better than the previous diode bias)…just like Vidar.
As a result, Magni 3+ had to move to a 4-layer board, while Magni 3 had been 2 layers. Magni Heresy had no problem running at 2 layers. More layers equals more money, more parts equals more money. Magni Heresy uses more expensive parts, so it’s kinda a wash, but the fact remains: Magni 3+ is a more complex amp.
It got worse. Early protos of Magni 3+ were unstable. I had to change the compensation to make it work with the driver stage.
Aside: a question to the engineers out there—what does the driver stage do, and why does it change the loop gain characteristics of an amp? Bonus: why would you want a driver stage in a speaker amp, but maybe not in a headphone amp? Why might you go to Darlington drivers in a speaker amp?
Luckily, I found a simpler compensation method (technically, Miller Inclusive Compensation) that was both simpler and more effective than Magni 3, so the parts count actually went down on the second prototype.
Eventually, I had both a Magni 3+ and Magni Heresy. I took them both home, together with a current Magni 3, to do some listening comparisons…
