Either way, if you didn't design/simulate for the no-load condition you might as well stop advocating yourself as a 'player' in the class-D market. That's one of the first things you look at after you've verified the design is working. You try to break the design by looking at all the worst case scenarios (that also included DC at the input tbh).
So 1) either Nuforce has some really incompetent engineers (the build quality of these amps suggest that) or 2) they just tried to cut another corner and left out a simple zobel network that acts as a load when no load is connected.
They saved themselves a few cents per amp that way, but that's negated by a single amp dying of that cause. I think I commented in the other Nuforce thread already about the economics behind the abismal build quality of these amps and suggested that Nuforce looks to be cashing in on the class-D hype with cheap amps that aren't built to last.
Best regards,
Sander Sassen
http://www.hardwareanalysis.com
So 1) either Nuforce has some really incompetent engineers (the build quality of these amps suggest that) or 2) they just tried to cut another corner and left out a simple zobel network that acts as a load when no load is connected.
They saved themselves a few cents per amp that way, but that's negated by a single amp dying of that cause. I think I commented in the other Nuforce thread already about the economics behind the abismal build quality of these amps and suggested that Nuforce looks to be cashing in on the class-D hype with cheap amps that aren't built to last.
Best regards,
Sander Sassen
http://www.hardwareanalysis.com
Zobel Network
If one reads B&O/IcePower recent EPO patent application, their inventors describe the need (or not) of Zobel network. IcePower has had their share of overheat problem. Their PCB for the 1000W module on the unit I have is at revision F (and overheat protection), Their spec says the 1000W module is good for 85W continuous unless more heatsinking is provided.
In their more recent design the Zobel network has been removed, as they apply their recent patent app's principle in the design.
Zobel network according to a golden ear I know degrades the sound. By the same token audiophiles are known to buy expensive cables and all sort of mods to get better sound from their gear. Vinnie and Dan on Audio Circle make their living doing mods such as changing wires and using Black Gate capacitors which are even more expensive than UcD modules. Cost doesn't seem to be a deterent to their quest for sound/audio performance. That having been said, there're differences between "industrial grade" audio gear which is robust but sounds boring, and audio tweaks that won't meet "industrial grade" criteria but preferred by audiomaniacs. Removal of Zobel network on NuForce amp may be one of their tweaks. On their PCB there are uninstalled cap and resistor at their speaker output pads.
The marketplace is mostly imperfect. The "best" product has its own problem, such as Jaguar cars known to be unreliable, yet rich people buy them.
If one reads B&O/IcePower recent EPO patent application, their inventors describe the need (or not) of Zobel network. IcePower has had their share of overheat problem. Their PCB for the 1000W module on the unit I have is at revision F (and overheat protection), Their spec says the 1000W module is good for 85W continuous unless more heatsinking is provided.
In their more recent design the Zobel network has been removed, as they apply their recent patent app's principle in the design.
Zobel network according to a golden ear I know degrades the sound. By the same token audiophiles are known to buy expensive cables and all sort of mods to get better sound from their gear. Vinnie and Dan on Audio Circle make their living doing mods such as changing wires and using Black Gate capacitors which are even more expensive than UcD modules. Cost doesn't seem to be a deterent to their quest for sound/audio performance. That having been said, there're differences between "industrial grade" audio gear which is robust but sounds boring, and audio tweaks that won't meet "industrial grade" criteria but preferred by audiomaniacs. Removal of Zobel network on NuForce amp may be one of their tweaks. On their PCB there are uninstalled cap and resistor at their speaker output pads.
The marketplace is mostly imperfect. The "best" product has its own problem, such as Jaguar cars known to be unreliable, yet rich people buy them.
Hi Chris,
Allow me to answer that question for you:
NuForce Reference 8 amplifier, debunking the myth?
http://www.hardwareanalysis.com/content/article/1828/
Best regards,
Sander Sassen
http://www.hardwareanalysis.com
Allow me to answer that question for you:
NuForce Reference 8 amplifier, debunking the myth?
http://www.hardwareanalysis.com/content/article/1828/
Best regards,
Sander Sassen
http://www.hardwareanalysis.com
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