And if it just so happens that your choice likes to wallow in one-ohm territory, the correct response is to buy amps that are comfortable driving one-ohm loads.
@devinplombier If you want the most out of your amplifier investment dollar, avoiding loads like this is a very good idea. All amps make more distortion driving lower impedance, which is heard as not as smooth, not as detailed (and speaker cables become for more critical!). You always want the amp to be loafing for its job, allowing it to have a lot in common with sitting on a park bench. That's when the amp, regardless of its technology, will sound its best.
Based on what I’ve heard in my studio and what I’ve read on LAiV’s website, I am guessing the GaNM amps are operating at a sampling frequency that’s so high it does not require feedback, and as a result, current and voltage remain in phase.
@hilde45 FWIW Dept.: With this comment he really showed he didn't know what he was talking about.
Dead time is a device used in any class D amp to prevent the output section overheating and failing very quickly. It is the same amount of time needed to keep a given device (MOSFET or GaNFET) cool and does not vary with switching frequency. So when the switching frequency is higher, the dead time makes up a greater and greater portion of the pulse train- essentially increasing distortion. So you have an increasing need for feedback as switching frequency is increased. You do get more loop gain with higher switching frequencies, so its possible to have more feedback.... At any rate, the reason to use GaNFETs isn't speed so much as being able to reduce switching noise because you have far less parasitic inductance in the output section.
To give you an idea of how much lower that noise can be, our class D is between 60 and 70dB below the value set by the EU Directives (for which you obtain the CE mark), and that is caused by the power supply rectifier in the amp rather than the output section! As a result there are a lot of tube amps (like the Dynaco ST35) that radiate more noise than our class D. Keeping noise down is vital if you want associated digital gear to work properly!
But still:
- Not truly continuous like tubes or Class A
That really depends on who you talk to. I can point you to some people who say quite the opposite. FWIW. AI really can't be trusted!
Or is an audio show a bad place to read the tea leaves, at least in some respects?
@hilde45 I think its a bad place to read the tea leaves.
That is because the musical instrument amplifier market (guitar and bass amps) consumes 90% of tubes made worldwide. Class D is now invading that market too; Fender, using the Sunn marque, has just released the Sunn Beta Lead amp, which is class D.
Since most guitar players use effects pedals to create their 'sound', all the guitar amp has to do is not be annoying. Its not like it was decades ago when Jimi Hendricks got his sound by overdriving his Marshall amps! It makes a big difference if you are waiting for the headlining act to get done with their set so your band can finally move its gear out of the venue at 3:AM, that your amp weighs 15 pounds instead of 85! So in ten years the tube market is going to look at lot different. The larger tube producers are going to have to sort out what to do when 90% of their market is moving away from them.
the Shuguang factory closure in 2019,
It closed because it burned down. It got rebuilt about two years ago and is producing tubes once again.
I don't intend to stop playing with tubes since its fun. We're actually working on a tube prototype right now but I've got no illusions it will be better than our class D. But some people still can't make that leap, so we'll have something for them (that also uses tubes that will be easier to find as sources dry up).