What Class D amps will drive a 2 ohm load


Just asking.

I see specs into 4 ohms but nothing into difficult speaker loads (like Thiel CS5's).

Thanks for listening, 

Dsper


dsper
nitrobob
I have Legacy Focus mains

Very nice speakers but sorry a b***h to drive, neither your amp (mosfet) or a class-D will suffice, they’re just not up to getting the very best out of these Legacy’s

That’s a pretty nasty looking impedance and -phase angle graph.
Read back at amps I have suggested and you get the idea of what you need.
Doesn’t have to be high wattage 50-100w will do, as those speakers are 95db, BUT!! you need gobs of current all the way down to 2ohms, look at what I say about "almost doubling wattage" for each halving of impedance, then go and search for amps that come close to doing this.

https://www.stereophile.com/images/archivesart/LEG20FIG1.jpg
(fig.1) reveals that it needs to be used with an amplifier that can deliver high current into low impedances.
Not only are there two minima in the bass of less than 2 ohms, and another of less than 3 ohms in the mid-treble, but there is an amplifier-crushing combination of 3.3 ohms magnitude and 60 degrees capacitive phase angle at 20Hz

Cheers George



@nitrobob - it would appear that V series amp is based on the IcePower 1200AS1/2 modules (not sure if it’s the 1, 2, or combination of both), which has a minimum impedance of 2.7 ohms. They also mention you should use a 20amp circuit for best results.

You might want to consider using a high current stereo amplifier for left and right channels only, and something different for the center, and surrounds.
Thanks guys. My current ATI 6005 uses two 20 amp circuits as I had to run a dedicated line for my second output.
OK, so what is the definition of instability for these Class-D amplifiers?
Stability is the same definition regardless of the kind of amplifier. It is the ability of the amplifier to resist oscillation.
Oscillation has nothing to do with whether an amplifier can double power as impedance is halved, and has nothing to do with whether or any such nonsense. Its simply means the amplifier won't oscillate.

Now one thing that potentially could muddy the waters: it is possible to build a class D amplifier that is self-oscillating. This is done using the feedback loop with the intention of using the oscillation frequency in the encoding process of the amplifier. This is a handy technique as it also allows the amplifier to correct for phase shift in the audio passband. But such an amplifier could still be able to oscillate independently of its self-oscillation if there were a design bug! Confusing- but there it is.
Hi Atmasphere,

I tried some multi-strand 10 gauge copper wire on my Thiels. This replaced 16 gauge lamp cord. Fifteen foot lengths.

Can definitely tell a difference, an improvement. There is more detail, which seems to add better decay in general; cymbals sound more real.

Thanks for the advice,

Dsper