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The Future of Audio Amplification

I have recently paired an Audio Research DS225 Class D amplifier with an Audio Research tube preamplifier (SP8 mkii). I cannot believe how wonderful and lifelike my music sounds. The DS225 replaced an Audio Research SD135 Class AB amplifier. Perhaps the SD135 is just not as good as some of the better quality amps that are out there, but it got me thinking that amazingly wonderful sonance can be achieved with a tubed pre and Class D amp. I have a hunch that as more people experience this combination, it will likely catch on and become the future path of many, if not most audiophile systems. It is interesting that Audio Research has been at the forefront of this development.
distortions
georgehifi's avatar
georgehifi
10,312 posts
 
600khz v 1.5mhz switching frequency
The higher the switching frequency the higher the low order output filter can be set, so by the time the residual reaches 20khz what’s left with the 1.5mhz is down nearly 3 lower in amplitude and has less phase shift in the audio band than that of normal 600khz switching frequency. Blind Freddy can see that.
atmasphere's avatar
atmasphere
11,935 posts
 
^^ This is partly true as written.

George, the residual **is** the switching frequency. So this bit
so by the time the residual reaches 20khz what’s left with the 1.5mhz is down nearly 3 lower in amplitude and has less phase shift in the audio band than that of normal 600khz switching frequency.
doesn't make sense as written. I think what you are trying to say is that with a switching frequency 3x higher, the residual will be reduced (given that the filter in question is the same whether the amp is switching at 600KHz or 1.5MHz). Its helpful to express this in db; assuming a 6db slope the residual will be down an additional 9 or so db. Which is nice!

The 20KHz part has nothing to do with it. Whether you measure at 20KHz as opposed to 20Hz (if you change the timebase on the oscilloscope if you are observing either frequency as a test signal) the residual will be the same amplitude.
georgehifi's avatar
georgehifi
10,312 posts
 
I repeat,  Blind Freddy can see that.
tarheelneil
35 posts
 
Stevecham, and yet Paul McGowan of PS Audio maintains that the Stellar is no match for the BHK, or Class A and AB in general.  He produces them mostly because of customer demand.  
ricevs
1,543 posts
 

PS Audio is using older IcePower technology modules (completely stock).....not the latest IceEdge.  Because of this they have to add a buffer to color the sound to make it more acceptable.  The output wires run to binding posts that are two inches long and have push on connectors on them......very not tweak. The IceEdge modules are far better sounding and with tweaks they sound amazing.   Yes, PS Audio is behind on this one.  I will be A/Bing my super tweaked dual mono IceEdge based amps with the BHK.  We shall see what we get.  

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