Class D is just Dandy!

I have been running an old Class D Rotel RB 1072 for years.  I slowly upgraded everything around it by adding

Sonos (wyred4sound mods)
Wadia 321 DAC
Rouge Audio RP1 (tubed pre)
Focal Aria 936

Each of the upstream upgrades were a long range plan to try and stay with a class D amp.  Finally about 3 weeks ago I tried the new PS Audio Stellar S300 amp.  I just called them to inquire but when they offered a good price on the Rotel as trade in I took the hook.

I think they got one of the engineers from Classe' to do the ICEpower implementation.

I am completely satisfied with the improved sound (proly a slam dunk considering where I was).  I have pretty much turned off my Velodyne Micro V.  Enjoy the tone and increased realism and sound stage.  Running a little warm but nothing like a class A/B Unit.  Now I can turn my attention toward my TT or SACD player.

If you have an amp to trade in, the S300 can be a real value.

Let the crack habit continue.

I experimented with two Class D amps in my system; Merrill Audio's Taranis and Digital Amplifier Company's Maraschino Monoblocks. My system consists of an Esoteric X-03 SE CD/SACD player -> PS Audio DirectStream DAC -> amp -> Reference 3A DeCapo BE. 

I chose Tommy O'Brien's Cherry Amp Maraschino monoblocks over the Merrill Audio Taranis. Nevertheless I found both amps to be detailed, powerful, and musical...albeit the Taranis more powerful at 400WPC. The Cherrys are small, efficient, and at 6"x6"x8" easy to move around; the Taranis is a single-chassis configuration. However the Taranis' single-chassis configuration did not figure into my decision-making.

Tommy encapsulates his Maraschino models in their own shielded enclosure, mounted atop a marble block for stability, and separate from their outboard power supply. I like that the amp is contained in its own housing. IMO it minimizes interference between the amp and power supply. Taranis probably does as well but w/ the Cherries, I can verify the separation.

Each Cherry amp was meticulously packed, w/ its accompanying ps, in separate boxes. DC cables (ps to amp) are included, as is a pair of RCA to Balanced adaptors...how thoughtful is that?

Neither the Taranis or the Cherry amps sounded their best out-of-the-box. However after 48hrs of continuous power with about 10hrs play-time in between, the rough-edges were gone. That's when I realized Class D was worthy of my serious consideration...ymmv.

Will these be the last amps I ever own? I don't know. I'm the unsettled-type who likes buying new gear periodically. For now, I'm happy with my purchase. If I could want for anything, it would be an increase in gain from 22db to at least 26. But I trust Tommy knows best. After all, he's likely forgotten more about amplifier design than I will ever know.

In closing, if you're considering evaluating a Class D amp, I think you'll be surprised. It ain't the undeveloped technology it may have once been. Pick one of the brands bandied about here, give 'em time to break-in and make up your own mind. PM me if you want to hear more about the Taranis.

Two more questions regarding amplification modules:
How different is the sound of a Hypex from the sound of an ICEpower? Do they have distinctive sonic differences?
And how important (or not) is it to have a dual-mono (in a stereo single case) rather than a single amplification module to produce stereo?

I don't think the case makes as big of a difference as the power supplies.

Both ICEPower and Hypex allow you to use a single power supply for 2 channels.

This has potentially two benefits:

- Headroom
- Channel separation

Lots of good stereo amps share a single power supply though, so having dual-mono power supplies is by no means an absolute requirement.

Spec-wise, the Hypex modules are better at very difficult loads, like electrostatic speakers. In practice with "normal" speakers, I can tell you I have the ICEPower in my living room and cannot hear a difference from a linear A/B amplifier. I have Hypex designed amps on my desktop system, via an NAD D 3020, but this is a bit of a unique design. All I can tell you is I'm very happy with both.

Best,

E

Hi migueca,

     I agree with Erik that the main benefits of mono-blocks, regardless of the amplifier type, are increased headroom and channel separation but with the former being more obvious than the latter.

     Increased headroom in an amp is mainly evident in its ability to more accurately reproduce the large dynamic range of live music.  My experience is that a system's ability to quickly and powerfully reproduce musical passages that progress from soft or moderate volumes to suddenly higher volumes significantly adds to the illusion that you're listening to live music in your listening room; amplifiers without large amounts of headroom and the ability to deliver it quickly typically will not be able to convincingly create this illusion.
     However, there are class D stereo units available that contain 2 power modules, with a devoted power supply for each, combined in a single chassis.  Some of these dual-mono stereo amps even utilize separate power chords for each channel/module.  I've never compared the performance of a dual-mono  stereo amp to a pair of mono-block amps but I believe most people, including myself,  would be hard pressed to  distinguish between the two.

     Technically, with mono-blocks having each channel contained in its own chassis and physically isolated from each other, it would be expected that their scientifically measured channel separation stats are superior to dual-mono stereo designs.  Whether you'd actually hear this superiority is questionable.

     I've used 2 different stereo class D  amps in my system (a classD Audio SDS-440CS and an Emerald Physics EP-100.2 ) and currently use a pair of D-Sonic M-600-M mono-blocks.  I would characterize them all as having very good channel separation with a solid and stable 3D sound-stage illusion.  I haven't noticed an obvious improvement in channel separation with the mono-blocks but have definitely noticed an increase in headroom and a greater dynamic range with the mono-blocks in my system.

     I know from your posts that you're thinking of trying out a good class D amp in your system and you're considering trying a Ghent or a ClassD Audio model.  I highly recommend my first class D amp, the classD Audio SDS-440-CS.  It's a true high quality bargain at only $630.  It's powerful (220 watts @   8 ohms/ 440 watts @ 4 ohms), has extremely low distortion levels, very good bass response, is very detailed and neutral in sound character with music emerging from a dead silent background.  The mid-range and treble response is very smooth and never bright or harsh like a tube amp without the treble sounding rolled off at all.  Here's a very accurate review from a professional reviewer: 
  
www.highfidelityreview.com/class-d-audio-sds-440c-amplifier.html

     They also give you a 30 day in-home trial period with a 'no questions asked free return policy' if you don't like it for any reason.  Very low financial risk involved but I seriously doubt  you'll want to return it.

Enjoy,
 Tim