Yes switching frequency, also dead-time. You want to have as small a dead time as possible for best performance.
One great thing about GaN fets is that the reverse recovery charge (Qrr) is zero (0). This eliminates a loss element completely that is present in non-GaN devices.
The design goal is not efficiency, that is secondary. The #1 design goal for all these modules is audio performance. Efficiency can be further improved at the sacrifice of audio performance. Here are some efficiency and dissipation numbers for my amp's power stage.
Manufacturer eval boards are not meant to be used this way. They are designed to showcase the technology in this case particularly the efficiency of GaN Fets which this eval board achieves.
It is always up the designers to tweak it and make it better for their purposes.
These are mass...
My stuff has already been verified by 3rd party. AudioXpress here:
This behavior as I see it comes from two sources.
1. Inductors (the larger inductors have slightly better frequency characteristics)
2. Feedback (ultra has higher gain and therefore more feedback)
These two coupled together means that distortion does not increase as much as the frequency...
For those that have ordered bare boards, orders have started shipping. Be on the lookout for an email from shippo (goshippo.com) with your tracking information.
For those that ordered completed modules orders will start shipping in about 2 to 3 weeks.
For those interested the preorder is now...
Both amplifiers use my proprietary dual feedback modulator, the modulator is what mostly gives the amps the sound signature. So both amps will sound very much alike. I decided not to modify the modulator for the more powerful amps because the 150W ones got such rave reviews and now also received...