Class D: Turns Out it Does Suck!

[Ralf11]

What is the least expensive Class D amp that will sound a lot better than my 1990s Sunfire amp?

 

(must have good current delivery at 4 ohms)

[Ralf11]

I wonder why Audio Research dropped class D ??

[Ralf11]

11 hours ago, firedog said:

Relevance?

Do you also wonder why other brands have picked up Class D? 

 

Neither is actually relevant.

Companies make decisions like that all the time. Lot of different reasons. Sometimes they drop a technology and then readopt it afterwards.

 

Sometimes different companies disagree, imagine that. None of it proves anything. Expert amp designers also disagree. I've yet to understand how cherry picking the expert who goes along with your opinion proves anything - it's not as if all respected amp designers agree about class D. 

Same thing with all other types of audio components. 

 

not sure why most of your verbiage seems aimed at my post

 

If I had to guess why Audio Research dropped class D  it would be lack of fit with a storied tubed electronics line and consequent low sales.

[Ralf11]

The signal that goes INTO class AB or class B is NOT the signal which comes OUT.   What comes out of class AB or class B is a modulated and filtered facsimile with cross-over distortion.  That's why it has been pointed out that class AB or class B is mathematically, physically inferior to linear class A amplification.  Of course, there are benefits to this trade-off, as always.

[Ralf11]

Gallium

 

that's where it's at

[Ralf11]

check this puppy out...

 

 

[Ralf11]

There are several issues involved in this thread:

 

1. Can (or does) Class D match the SQ of the very best Class A or Class AB amps?

2. if so, which products do so for less $$

3. Are any Class D amps a match for a very good Class AB amp at a particular price point, say around $3,000 or $1,000, etc.

4. Do Class D amps offer adv.s for particular uses (inside a speaker box; driving a low ohm load; driving a very complex impedance), etc.

[Ralf11]

39 minutes ago, gmgraves said:

 

I would love to "check this puppy out" except you haven't told us anything about it. What's the brand? The model number? And most importantly, where can we find this, IOW, whats the URL?

 

it Looks GROOVEY - that's all the counts!

 

 

(yes - it is a $125 Chinese made integrated (tune/SS) with Bluetooth) from monoprice.com

[Ralf11]

I wonder how it sounds?

 

(But who cares - slap a 5 digit price tag on it and the placebo effect will by YUGE!)

[Ralf11]

36 minutes ago, GUTB said:

euphonic glow

 

 

...

[Ralf11]

The constant switching of Class D made me ‘Mildly Nauseous’ About the Electrons.  But It’s Not Enough to really worry about.

 

 

[Ralf11]

Live in town, don't drive, don't have kids...  but everybody gets to pick any electricity saving or other energy saving activities

 

Now, what about intermodulation between the scan frequency and the input signal?  Is that a problem with current Class D designs?

[Ralf11]

My Sunfire is still going strong at age 22 !!

 

(I do listen to it for impending doom however)

[Ralf11]

change your name from gutb to Tenacious D

[Ralf11]

you're not backing up your conclusions about Class D

 

Let's forget about mechanism, and just explain which Class D amps you've heard, the cost, and how old the design is with some specifics on the particular SQ flaws each time

[Ralf11]

ok - who else has heard the D-Sonic?  and did it crush your soundstage?

[Ralf11]

While I am sorry that your soundstage was crushed and your money wasted, it does seem that this event has overactivated your limbic system.

[Ralf11]

It is the electrolytic capacitors that tend to not last over 20 years or so.  Or maybe it is just the  electrolytic capacitors that were used in the 1980s or 1990s.

 

Now to get back on topic...

 

My Sunfire amp uses them and it won't last forever, so what Class D amp will sound better and costs less than the $3,000 Benchmark AHB2??

[Ralf11]

Yes, it is.  The guy who assembled that amp must be a genius!

 

 

... what with routing all the wires and all

[Ralf11]

[Ralf11]

12 hours ago, esldude said:

I'll give my subjective impressions though you weren't asking me. 

 

Class D when good sounds fast and powerful.  And it doesn't seem to care if you use very nearly all of that power as the sound quality stays consistently clean at all levels. It is capable of depth and space when its on the recording.  It doesn't create it however leading some to think it clinical. 

 

Spectral amps have the speed of class D and maybe more.  They sound powerful and relatively unaffected by how much you use, but not quite to the extent Class D does. 

 

Good class A amps shouldn't care about power used, but they do seem to fog up just a bit when much of it is used. Sometimes that fog is heard as additional space and dimensionality.  They don't fall apart the way some class A/B amps do when pressed into using lots of the available power.  Some of the finest A/B amps don't leave much to choose vs class A. 

 

Push-pull tube amps are a different thing altogether much more effected by what they are connected to.  You'll just have to listen and hear it for yourself. 

 

Thanks!

 

Any thoughts on the PS Audio Class D gain cell (non-Class D initial or input stage) sound?

 

esp. if it get fed by a tubed pre-amp (ARC LS25 Mk II)....

[Ralf11]

ah yes - that is the warm tubey goodness (tho there is less phaat in the newer ones)

[Ralf11]

9 hours ago, esldude said:

Looking at stereophile measures the Gain cell is the PSAudio input stage feeding an ice power amp. The only obvious differences are more noise than ice power amps usually have.

 

which issue has the S300 review?

 

Here is PS Audio's claim: "The S300’s rich, warm, and engaging sonic character comes from the Analog Cell."

 

also: "musicality"

 

The Analog Cell is a [1] zero feedback, [2] Class A, [3] MOSFET input stage...

 

One nice thing is that it's fairly cheap - if I trade in my old Adcom it'll cost ~$1,000...

[Ralf11]

Aren't those $1k/channel with no case?

 

I am also submerged in DIY projects...  and then there is the putative benefit of the Class A front end...

[Ralf11]

Thx - waiting is no problem; tho it looks like 2 of the N400s with case are only $750 (in Europe) and are trivial to assemble