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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
 
So that makes the scan frequency in this example only 200KHz(!),
Wrong again when have you seen an amp that can do 200khz, have a slewing audio frequency square wave like this, the sides are collapsing in like the leaning tower of pizza

Our OTLs are quite good at 1 watt 20KHz squarewaves too.
And that is where you should stay linear and with tubes, otl, even add trany coupled, so your not hamstrung to certain speakers. You built your rep on them and now your going to destroy that?. Not a good move, it will come back and bite you on the arse, your just another respected amp manufacturer saying "give me some of that class-D action"
atmasphere's avatar
atmasphere
11,936 posts
 
So that makes the scan frequency in this example only 200KHz(!),
Wrong again when have you seen an amp that can do 200khz, have a slewing audio frequency square wave like this, the sides are collapsing in like the leaning tower of pizza
I think you misinterpreted this. The amp at the link you provided was an older amp that was only switching at 200KHz. Nobody has been building amps with switching speeds that low in a long time, unless its for subwoofers only. Also, we don't know why the risetime is as slow as it appears since the data on the amp itself is lacking. That can be caused by measurement errors, but it can also be caused by analog signal processing before the encoding scheme.

So its erroneous to apply the results of this nearly 20-year old circuit to newer amps.
georgehifi's avatar
georgehifi
10,312 posts
 
I think you misinterpreted this.
Nobody has been building amps with switching speeds that low in a long time
Geez Ralph other way around, get with it, in this case I wasn’t talking about 200k switching speeds, I was talking band-width and the slewing of this square wave I posted up, with and without switching noise embedded in it.
agear
1,362 posts
 
Ralph, you are more capable than anyone on this thread to explain why class D is the future from a technical standpoint.  Lay it on us.  Also, have you (as George is implying) had a religious conversion to the world of class D to the point of implementing it in your products?
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