What Class D amps will drive a 2 ohm load

@noble100 Yes, Bruno has been able to design class D amps with loop gain north of 75dB!!

He did acknowledge to us that there was a typo in one of his papers when we pointed out a math error regarding the oscillation criteria. It was not an error in the paper itself though, it really was a genuine typo. Brilliant guy.

Here's  another interview with Bruno Putzey and Lars Risbo on their new Purifi Class D amps.

https://audiophilestyle.com/ca/bits-and-bytes/purifi-audio-and-the-audiophile-style-readers-qa-with-...

Bel Canto e1X, stable into 2 ohms. See recent Stereophile review.

Like I said, "stable into 2ohms" is a smoke screen furphy, to make the gullible feel it can happily drive 2ohms without strain, it just means it won’t oscillate and blow up, as Ralph also said two of his post back.
So is a 1980’s 30w Nad-3020 stable into a "2ohm load", but there’s no way in the world it can drive it without any strain, if it could you would see the 4ohm wattage almost double into 2ohms, but that’s not given with the BC for a hidden reason.

Even the Stereophile tests show the eX1 can’t even get close to doubling from 8ohm to 4ohm!!!, let alone the 2ohm, it for sure would have gone backwards, instead of up if it was given.

340Wpc into 8 ohms
530Wpc into 4 ohms

Your welcome George

The output impedance of almost any class D amp is so low that doubling power as impedance is halved is no problem, even into 2 ohms.


The limitations are current capacity in the output section, current capacity in the power supply, heatsink capacity and finally issues surrounding the output filter. Its likely that the latter will be most problematic, which is why self-oscillating is attractive since it will allow the amp to correct for phase shift induced by the filter. Getting output devices that can handle the current is academic at that point- its all about how far you want to push it in the design- you face most of the same constraints you do with a class AB amp.

With this Bel Canto e1X, even the 8ohm to 4ohm is a tell to what the 2ohm wouldn’t/couldn’t do grunt wise.
That wasn’t even considered to be measured as it would have fallen flat on it’s face like all Class-D’s do that I’ve seen, but at least it's stable into 2ohms and won't blow up. (so is a Nad 3020)
340Wpc into 8 ohms
530Wpc into 4 ohms