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High end Class D amps?

Just an observation and a question. Are there 'high end' Class D amps out there that are just as good as Class A, A/B amps? I realize that's a sensitive question to some and I mean no disrespect---but whenever I see others' hifi systems on social media, all of the amps are A or A/B. There's always Pass, McIntosh, Moon, Luxman, Accuphase, etc. Where are the Class Ds? For folks out there that want more power for less efficient speakers and can't afford the uber expensive Class As, A/Bs, what is there to choose from that's close to those brands? Thanks
bluorion
grk
223 posts
 
While not Class D, check out the Cherry Amps which are digital.

https://www.cherryamp.com/
klh007
621 posts
 
@grk, Tommy's Cherry amps are Class D.
djones51
4,947 posts
 
I'm not saying anyone is being deceptive all I'm saying is the signal manipulation is occurring in the Rogue buffer board not the Hypex modules. There are no wires attached to the hypex in either the Sphinx or Dragan which is supposed to be TubeD or something.
jaytor's avatar
jaytor
761 posts
 
I don't have access to the documentation for the Hypex modules used on these amps, but the connector is the same (except for one status line) as the Purifi module. There is no provision on the Purifi connector to bypass the driver circuitry. I suppose it could be possible to have jumpers on the card which would do this, but it seems unlikely since this circuitry (on the Hypex board) is an integral part of the feedback design that makes the Hypex module function. 

The Hypex and Purifi modules do expose the outer-most feedback loop, which is designed to provide a feedback connection from the speaker connections (or as close to the speaker connections as is practical). This is generally connected to the speaker output connections on the buffer board. It could be possible that Rogue is adding circuitry to this path to alter the Hypex module's transfer function, or someone integrating their front end buffer inside this feedback loop. 
djones51
4,947 posts
 

Operation is based on a non-hysteresis 5th order self-oscillating control loop taking feedback only at the speaker output.

Furthermore, the NC500 OEM is an unbuffered amplifier leaving the implementation of an input buffer up to the manufacturer. The NC500 is practically devoid of any sonic signature so this external buffer is a good way of tuning in a “house sound”.


It looks like in the Dragon they use the NC500. I assume they’re doing what every other manufacturer that uses this module they’re adding their sound with theirs or a third party external buffer. IMO it’s preferable to leave the signal as transparent as possible and not muck it up with distortion but to each his own.
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