Power Supply for Digital Amp.


Much has been made of the fact that the H2O digital power amplifier has a robust "linear" power supply. Supposedly this is important. Manufacturer's info (a referenced review) on the CI Audio D200 amp states that all ICE and TriPath amps lack "split" power supplies and end up with "floating DC" on the outputs. For ICE, the H2O would have to be an exception. I checked my CarverPro ZR1600 amp, which is TriPath, and find that it has a good old fashoned (simple) +/- power supply, with 40,000mfd on each leg.

It seems to me that some marketing mumbo jumbo is going on about power supples in digital amps. Perhaps the amplification circuits are thought to be too hard for us to understand, so they talk about the power supply. What do you think?
eldartford

Showing 1 response by eldartford

Joeylawn36111...There is much truth to what you say, although some amps have been (and are) made with less-than-satisfactory power supplies, because it is an easy place to cut corners and reduce cost. When the "rail" voltages of a power amp "sag" (go down) as a result of heavy draw when music is loud, the output of the amp would be affected EXCEPT that the feedback loop will detect the signal error and more fully turn on the output transistors to compensate for the lower voltage applied to them. Because the power supply voltages are heavily filtered, voltage variation will be very slow (compared with audio signals) and can be tracked by a feedback loop having little or no effect at audio frequency if feedback is considered undesirable. Finally, if power supply "sag" were really a problem we would see amplifiers with regulated "rail" power supplies. Are there any?

As you say, the role of the power supply is to provide a steady voltage, and nothing could be easier to verify.

The claim that I find most difficult to swollow is the superiority of tube rectifiers. Can someone elaborate on this?
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