Any experience with Class D amps and impressions?

The Allo + series amps use active onboard filtering and reservoir to alleviate some of the limitations of pulse mode power.
 
With GaN, the ultrasonic high frequency noise "shoot-through" is already significantly reduced vs MOSFETS. Most of the development with GaN has been focused on amplifiers. But GaN can and is being developed for SMPS as well, with reduced noise and clean, usable power. Development in both Class D amplifier and SMPS employing Gan is progressing at a rapid pace and even now, producing stunning audio quality. Its just a matter of time.
Since Class D amps have very high efficiency levels (>93% ?), the Linear Power Supplies only need to be relatively small (and not take up that much more extra space) to effectively power them to hundreds of glorious Watts per channel, without breaking sweat.
 
I've been using a Yamaha P7000s (750W x 2 @ 8 Ω; 950W x 2@ 4 Ω) for 5 years. Yamaha has a newer line: PX series models are driven by a newly developed Class-D amplifier engine with a custom LSI.

The PS series touted Yamaha's own digital EEEngine:

EEEngine delivers incredible power while preserving sound quality
As a power amplifier's output increases, its driving mechanism becomes more significant. Yamaha's exclusive EEEngine amplifier driving technology supplies the voltage level necessary for the level of input signal through switching circuit and smoothing circuit, producing a highly effective driving mechanism. This is a revolutionary power amplifier driving technology that offers the function of a Class AB amplifier and the efficiency of a Class D amplifier. EEEngine gives you fantastic power, highly efficient driving function, and tremendous energy savings, all without sacrificing the sound quality demanded of a professional power amplifier. This technology is included in many of Yamaha's power amplifiers, and proves its utility in all kinds of situations, from sound reinforcement to permanent installation.


I had previously used a QSC GX7 to power the front Polk RTia9s in a 7.0 HT; using a Pioneer SC-07 as a pre (the SC-07 was fine for HT; but => listening fatigue for 2-channel CD, I believe its early ICE amps' 140W was too little for the RTIa9s). They became "musical" with > 700 WPC. The fans on the QSC ran constantly, => low WAF.

I replaced the QSC with the Yamaha P7000S. The fans have never come on. I replaced the SC-07 with a Yamaha ‎RX-A1050 2 years ago. Use a BD-A1040 as a 2-channel source, amp & player in Pure Direct.

Recently upgraded the front 2 speakers to Focal Electra 1038BEs (93dB, 3.3 Ω min.) I've read a lot of Google that the Focals would be revealing of less than acceptable sources/amplificaton. I have no complaints. The Focals are a vast improvement over the RTia9s; the WAF? I didn't think I'd be able to hear the difference, but I can.

I'm using some very cheap RCA>XLR cables. The P7000S was a B-stock from ebay for $600.

Among the latest offerings, I've contemplated the PS Audio Stellar M700 monoblocks, as their form factor & looks are more conventional than the P7000S; and ~ half the power @ 5 X the price.
 
4xpddoc - funny you should bring up the PS Audio M700's. I just ordered a pair last week. We'll see how they stack up. Hope they don't take too long to break in - or even better if they don't need breaking in? Can't wait to compare them to what I have now.
 
The Volt+ on the left in a diy case cost $39 but it's linear power supply cost about three times that. It's close to the Volt+D in performance but the Volt+D uses an inexpensive power brick and hardly benefits ( if at all ) from a linear psu. As Pio noted the onboard filtering ( aka capacitance multiplier ) allows use of inexpensive SMPS.

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4xpddoc - funny you should bring up the PS Audio M700's. I just ordered a pair last week. We'll see how they stack up. Hope they don't take too long to break in - or even better if they don't need breaking in? Can't wait to compare them to what I have now.
I've heard a lot of good things about those. Their buffered input is said to match very well with the IcePower modules.
 
I have the Class D Audio CDA-250C power amp that is pretty decent. I'm not sure how old it is since I bought it off of another AKer in BarterTown, but it sounds good. My only issue with it is that is requires a lot of volume from the preamp to get my ADS L810 speakers going, which are quite efficient, so I'm not sure why I need to crank the volume up to the 12:00 o'clock position to get it to play at a sufficient volume. "Sufficient volume" defined as "not quiet but not loud enough to make people shout to be heard."

This amp is definitely good enough to keep my interest in class D amps going.
 
Got the M700's a couple of days ago. They are "warmer" and some might say darker than the ClassDAmp. They certainly tamed the higher end shrill I had. I just don't know if they'll change as they play more music. Also, have a lot of adjusting to do with the speakers as there are plenty of controls on them to do so. Also, will probably put some brighter op amps in my DAC as well. Hoping these will be the last amps I buy.
 
Well, I "rolled" op amps through my DAC and easily can tell the difference. Really makes my M700's keepers now. One set of op amps for rock and another set for all other music. I kinda like the options I have with the DAC op amps and the way the M700's sound as they give me multiple options and all fairly quickly. Now to sell all my big bad ass Class A/B amps.
 
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