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
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I am glad you know what you like. However, you are just guessing. You have never heard class D......so what do you have to contribute here? Just the same old "I don’t like how they measure, so they must not be any good". The fact is, that many have abandoned their class A/B, class A and tube amps for class D amps. This is a fact. I would never say that class D is better than any other class.....but in the last 5 year it has matured to be an equal competitor.

My own designed dual mono stereo 25 watt class A amp is very much like the Pass F5, except it uses dual differential pairs in the front end instead of just 2 jfets. The output stage is 3 parallel push pull mosfets and single feedback to the differential stage. 1.6 amps bias, only two resistors in series with the signal, DC coupled, no compensation, no current limiting, no binding posts (hardwired), 500 watt Plitron transformer for each channel, tons of power supply caps bypassed with modded Wimas, PCOCC wiring, damping of heatsinks and boards, no steel plates on transformers, no fuse, etc, etc. It sounds really, really great. But my modded IceEdge modules sound better. Now I am rebuilding the class A amp so it is in two chassis (the power transformers were interacting and to close to the circuit) and using even better resistors and wire and hopefully it now can compete or even beat my class D amp. We shall see. However, I could never produce the amp as it has no protection and who wants a 25 watt class A amp when you can get a 600 watt amp that sounds as good for less money and uses little heat and has an output impedance under 10 milliohm and input impedance of 150K!?!

If you go to Audio circle and go to the Nuprime circle and click on the thread on the Evolution One amps you will find a link to a review of their amp on Hifi-advice that is an interesting look at class D and its history.  For some reason I cannot put here the link to the review.  Worth reading.


Have you guys seen the AGD Gantube monoblocks?.....way cool! Check it out. Gans in a tube with 768K switching frequency. $15000 the pair. AGD production dot com.  Rave review on Positive feedback.
Which measurements, @kosst_amogan for which specific Class D amplifier?


Be specific.

Most Class D amps measure very well, if not superbly, especially compared to some megabuck Class A amplifier.
To write more, it’s not that I am dismissive of specs altogether, but rather that once amps get to a certain level of quality, the specs alone do NOT describe anything useful about the sound.


For instance, I’ve yet to see an amp with 0.01% distortion actually always sound better than another with 0.05% distortion at the same frequency and output power. In fact, below 0.1%, I doubt any amplifier sounds better or worse based on distortion alone.


So, Kost, what specifically and for which specific amplifier are you claiming a spec is significantly worse??


Best,

E