Oh how I wish Class D amps ...


I sure wish manufacturers and designers would move forward as quickly as is possible on improving the current status of Class D amps ... I have heard them all, some in my own system, and they have SO mcu promise !!! Unfortunately they just do not have it down yet. They still sound dry, unmusical, and strange in the treble ... kind of chalky and rolled off, and definitely lacking air.
I long for the day I can get rid of my hundred pound Class AB monster amp, for a nice small cool running amp that sounds just as good. I am worried though that designers and manufacturers have accepted the " It sounds good enough" opinion, and that the B&O Ice power may be a long time before it is "fixed"... sigh.
Just my rant ...
timtim
Class D is the amp of the future; always has been and always will be. LOL If they ever do get them fixed send me a message via medium as I will have been long gone.
'd' amps have a pretty good phase shift in the HF range due to the Zobel. If the frequency were higher, the turnover point could also be higher, getting the phase shift above the audible range.....
Maybe that's it?
TimTim

You created those really cool cables with your cousin to end your stint on the cable merry go round. Maybe you both can now focus on creating a great Class D amp. ;) J/K.
Heard them all-what did you think of the Devialet
TimTim,

I just built Hypex UCD400HG with HXR monoblocks. They exhibit none of the characteristics you lament in Class D. I built them with a Furutech IEC and Furutech RCAs, Neotech wire and Cardas Patented Binding Posts. They are simply excellent IMHO. They kicked my Berning ZH270 out of my system. In fact, they stomped on my Berning in every respect. The Berning simply isn't better in any area.

Treble is sublime and glare free, soundstage is wide and deep with excellent air and 3 dimensionality, bass is tight, deep and controlled, imaging is excellent, tonality is spot on, etc. They simply exceeded my expectations in all areas. I couldn't be more pleased with the results.

BTW, I am looking forward to hearing your new cables!
Heard the Dvialet @ CES, it's a hybrid Class A and CLass D amp, very cool and adaptable system and sounded really good, wickedly cool form factor as well!
Timtim:

"I long for the day I can get rid of my hundred pound Class AB monster amp, for a nice small cool running amp that sounds just as good."

Idea: LFD NCSE (not class D but worth a try). Barely a degree of heat even after playing hard all day. Lose one box, sell one set of IC's, spend windfall on more music.

One of the very few non-BS audio review sources: HIFI Critic
What did you think of the Digital Amp Company Cherry Plus?

It has consistently bettered all Class D I have compared it to - Spectron, Channel Island, Wyred, Rotel.

Was so much better than the Modwright 100SE in my system.

Curious to hear what was lacking from the Cherry Plus that you auditioned.

See the StereoTimes reviews for a good description of what it can do.

-Mike

-Mike
***and they have SO mcu promise !!!***

***They still sound dry, unmusical, and strange in the treble ... kind of chalky and rolled off, and definitely lacking air.***

Huh?!? What do you base the promise on?
Timtim ... your thoughts parallel mine . I have a 100 pound A/B amp and as i'm getting older, would like something small , light , and cool running . But have not heard a good sounding class D amp yet , I haven't heard them all . I don't think they will ever ketch up with A or A/B designs . And A , A/B designs are continually improving .
Ok guys ... I overstated when I said " I have heard them all " ... I should have said I have heard MOST of them. I find they all sound slightly different, but seem to still share the basic traits I described to one degree or another.

I have not heard the Devialet yet, but have heard the Cherry Plus in a friend's system, and it sounded good until he switched back in his own Class AB amp, and the Cherry's shortcomings were immediately highlighted.

I should also clarify that many of the Class D amps probably DO sound as good as many Class AB amps ... What I am looking for is for a Class D amp that can sound as good as amps such as the McCormacks, Claytons, Electrocompaniet, etc ...

And lastly to Frogman : The "promise" I speak of, is the promise of small size, efficiency, power, etc ..
You've heard them all, really? If they are not to your liking so be it. My experience with the W4S does not match your sonic description. I have a well regarded vacuum tube preamp in conjunction with a power supply that most users would not apply to a 1600.00 amp and the sonic result is excellent. You might try some other combinations of gear in your search.
Thanks Rhljazz ... I actually had the WFS 1000 in my system for a month, and it was a good sounding amp, but not even close to what my mcCormack offers.

I really, really want to go digital, badly ... I just do not want to go backwards in sound quality. My thread is not trolling, or trying to stir up any trouble. I just wanted to see what others feel about my thoughts and impressions. Thank you for your thoughts !
You can overcome the size/weight problem by switching to high efficiency speakers and using smaller A or A/B amplifiers. It is the need for enormous horsepower that requires you to own massive amplification.
There are some pretty great 30 watt SS amps out there that are not too large or massive.
I can't switch speakers, as I have NO doubts it would be a downgrade, regardless the price or brand. Owning a pair of Vapor Cirrus is the ultimate experience ;-)
Well, I have Rowland 102 class D amp that "sound dry, unmusical, and strange in the treble ... kind of chalky and rolled off, and definitely lacking air" and unmodified Benchmark DAC1 that according to another review suppose to "sound lo-fi and shrill". In addition I listen to CDs that again according to opinion expressed on this forum "I found almost all cds way to harsh and shrill sounding" and overall sound is short of amazing. Keep going guys - you helped me a lot!
" 'd' amps have a pretty good phase shift in the HF range due to the Zobel."

To the best of my knowledge no class D amplifier on Earth uses Zobel "filters". With Zobel, you would need to build up your amplifier individually to satisfy requirment of each individual speaker not to metion its other problem. It would be terrible creature....

All, with no exception, class D amplifiers have a challange in HF signal processing. Similar to that of traditional tube amplifiers in LF area and traditional transistor amplifiers in midrange.

Simon
There is no signal processing since most of class D amps are analog. As for the Zobel - Yes it is choke and output resistor and capacitor. Icepower calls it Zobel.

Excerpt from datasheet of Icepower 200ASC and 1000ASP modules:

"Due to the compensating Zobel network in the output stage, the maximum allowable short-term output power
is frequency-dependant."
I have heard many Class D amplifiers, the latest Nuforce can seriously challenge many, really expensive conventional amplifiers. Nuforce are the only switching amplifiers that I have heard that have a liquidity and presence in the midrange that rival really good conventional amplification.

I have heard the Bel Canto and other Ice amplifiers which sound much more hifi than the Nuforce.

If you haven't heard the latest Nuforce you should listen to a pair you will be convinced that these types of amplifiers have real promise.
Hello Kijanki,

I wish to apologize. I have had no idea whatsoever that ICE Power uses Zobel network. I don;t want my words to be iterpreted as even slightest critic of our competitor.

Still, for the record (and from our web site):

" Spectron designs team won a contact with pro audio giant Inter-m (among others in competition were Bang & Olafson and Philips)..."

Inter-M may be the biggest pro audio company and we are proud, as small team of 4 design & 1 production engineers, to have our design to win against somewhat more resoursful Philips and B&W ...but music lover have right to choose and be happy with any design they choose. Its a given.

If I offended someone - my deepest apologies again.

Regarding "There is no signal processing since most of class D amps are analog "..... before digital signal there was and still is analog signal which people for 100 years processed: from simplest as adding to most complex. Even computer does not need to be digital; some early computers were analog.... making my living for 30 years from digital signal processing I better know what I am talking about.

Respectfully,

Simon
Audiofreakgeek : I was loaned a Nuforce Reference 9 V3SE to audition, and found it rather dull in my system. Definitely a lack of air and extended highs. JMO
We should never underestimate the importance of system synergy and how some components are not a good match. Timtim, maybe a more appropriate elaboration would have been "Oh how I wish Class D amps would be a good synergy with my Vapor Cirrus speakers" :-)
Simon, - my bad! I tend to attribute everything to DSP forgetting that even simple analog filtering is form of signal processing.

As for class D - I believe that it is very good for the money (important to me). Opinions vary a lot. Some believe that class D is at reference level while others that class D is LO-FI.

Stereophile reviewed Bel Canto REF1000M (Icepower) ending review with this conclusion:

"The Bel Canto Ref1000 Mk.II can be compared with the cream of the other amps I've had in my system: the Classé CA-3200, Mark Levinson No.433, and Ayre Acoustics V-6xe. Each of these distinguishes itself in different ways, and particularly with different speakers. Because of this, I think I must keep the Bel Canto Ref1000 Mk.IIs as a reference amplifier—an easy decision even when based solely on its sound, but also: in my living room, none of the others can be so easily hidden in plain sight."

Class D amps might be very revealing showing shortcomings of the system but also might have better synergy with some speakers than others. Also, long break-in is most likely required. It took about 400 hours for my amp to sound best.

It is often said that Icepower sounds good only with linear power supplies. On the other hand newest linear class AB amps from Jeff Rowland (one costing $46k) use switching power supplies.
Well ... I guess I am wrong for assuming, but I do assume that EVERYTHING is always subject to system synergy. Having said that, the Cirrus speakers are the single best tool I have ever seen for component and wire evaluation. They are an open window, and PERFECTLY show every slightest change made upstream. So I am fortunate to have a system that does allow for very good evaluation.

I have no adgenda to bash digital amps, just a desire to see them improve.
Please see first schematic::http://users.ece.gatech.edu/mleach/ece4435/f01/ClassD2.pdf
L1 / C1 are how the switching frequency is removed.....and should induce a phase shift in the audio band. No?
Simon,
Want a good example of an Analogue computer?
Please see link:

http://en.wikipedia.org/wiki/Analytical_engine

Charles Babbage could never get it together long enough to build it, but within the last decade or so, Smithsonian built one to the original drawings, and it worked fine.
The machine would have been used to calculate log / trig tables for navigators and such.
Well ... I guess I am wrong for assuming, but I do assume that EVERYTHING is always subject to system synergy. Having said that, the Cirrus speakers are the single best tool I have ever seen for component and wire evaluation. They are an open window, and PERFECTLY show every slightest change made upstream. So I am fortunate to have a system that does allow for very good evaluation.

I have no adgenda to bash digital amps, just a desire to see them improve.

I think we all might have a bit of "that" same centricity that our speakers (or other gear) is neutral and that it shows the distractions of all other gear, but I tend to think that is not always so.

I think most might offer that "switching" amps have exceptional highs (in the better ones) and if your speakers are not letting you hear that, then what does that tell us?

In the end, it is finding the components that sum to our preferences.
The single characteristic that most impresses me about my digital amplifier (Tact) is the absence of noise-white, pink, or mechanical-it is simply absent. The result is that one can hear much more low level detail and much less compression than with any conventional amplifier I have used. Don't get me wrong, I have owned and loved well designed tube amplifiers (ARC, Music Reference, VTL), but they do make noise and compress the signal. I submit that many of us have simply got accustomed to these distortions, as previously we had got accustomed to tape hiss and grove rush. Because two channel sound is not the natural way we hear, the brain has to decide if a simulation we have created is "correct", meaning the usual distortions
All I know is that I had Bryston 7B-st amps, traded them for Rowland 201's and they didn't cut it. Now I'm back to big beef -- Cary MB500's. Speakers were Maggie 3.6's and Aerial 9's.

The Rowlands lacked oomph (in my system -- YMMV)

Rich
Summitav : RAAL OEM ribbons are simply the best high frequency transudcers on the planet IMO. They are the epitomy pf perfect highs.
Class D amps and their advocates remind me of the dated Ford commercial where you have the owner of a new Ford Galaxy( I'm dated too)espousing to the chauffer of a Rolls Royce, Fords claim that their product rides as quiet as a Rolls.The Chauffer,without hesitation says "maybe so but lets compare them after 20,000 miles and see which one is quieter"
TT,

What class D amps have you tried and what was the rest of the systems?

ALso what Class AB amps specifically?

I do not find the Class D amps in my rig match what you describe. Maybe I'm missing something, but I have heard a lot of good reference systems for comparison.

Of course, we all are entitled to our opinions.

If you do not want a big amp and don;t like Class D, then Macrojack had a good recommendation.
Check out Devialet. They have a class d/ class a hybrid amp that is getting rave reviews
Devialet must have the worst website and online infor I have ever seen. I tried looking into it, and can't even find power ratings, pricing, or anything else for that matter LOL.
Here's the key to Nuforce, must be left on, and warmed up for a day or two before listening, I never turn mine off, you need good power cords, and good power conditioning, and they must be broken in, in no way is the Nuforce dull.
Ya know ... as an interesting note to this ... If you look at MOST of the websites of the digital amp manufacturers, you will see where they boldly offer claims saying their particular amps offer more high end air and sweeter and extended highs than other digital amp offerings ... This alone is enough to hint that there are aknowledged issues with digital amps sound quality. You can find this type of claim on Cheery's, Hypex, W4S, and Nuforce just to name a few.

There own admission of this has to be taken as a concern, or they would never have even brought it up ;-)
I have the Nuforce Reference V3SE's. They require special setup that includes power isolation, and given their low mass and weight (about 7 lbs) vibration control and weighting on top to sound their best. They are worth these efforts. They respond well to tube preamps and do reveal the rest of the audio chain. Robert Harley of Absolute Sound just purchased Nuforce amps for his own personal home theatre system and praises their sound. He should have pretty good ears and access to top product.
A good friend of mine makes excellent Class D amps. I have heard them numerous times and did not think that they sounded the least bit "dry, unmusical, and strange in the treble". I would not confuse their sound with tubes, but they were not unmusical and they can drive the designer's Apogee Scintillas (1 ohm impedance) very nicely.

But....they are not "nice small cool running amp". They have VERY beefy power supplies. Maybe that is why they sound so good.

Anyway, if you want to hear what Class D amps can really do, check out this website and contact Henry:

http://www.iceh2oaudio.com/index_htm.html

Good luck.

Dave
Try Channel Islands class D 500W mono blocks which completely fulfill the promise of class D.
I'm running a TRL Dude in front of a pair of NuForce and it's the best sound I ever had, very liquid, relaxed, organic.

Audiofreakgeek and Gammajo are absolutely correct.
I noticed this subject posted last night with no responses and i thought i would check back and see where it has gone.It has gone up and down and all around and before it goes into the ether i wish someone would put together a roll call of all the current production class D amps, a master list,as there have been a few names mentioned that have garnered few sales and less press and might be worth noting.
The original "rant" puzzles me. It leads me to think that some negative experience has prompted him to "take on" the entire class D with broad generalizations.As an owner of a full tilt Spectron and two Wyred 4 Sound amps that all sound great i will not be intimidated by this "longing for the day" the day is here! and the music is delivered in a beautiful long flowing gown with bouquets of flowers and the scent of lilac and aged whiskey.Yes,the day IS here for the Class D amps, for paupers and kings and their tube preamps, and leave the knaves outside the walls to dribble their goo.
Jazzcourier ... My McCormack DNA-500 just destroyed the best from Wyred I had sitting here in my system ... Not even close... at all ;-)
"Jazzcourier ... My McCormack DNA-500 just destroyed the best from Wyred I had sitting here in my system ... Not even close... at all ;-)"

OK.

All that means is you prefer the McCormack.

Nothing more.
Sir Timtim,with a price difference of around 4500 buckaroos i would expect complete annihilation.
Please don't breathe a word of this to my vintage JBL 150's and AR 90's who have a serious crush on that Wyred amp.They positively get up and scream and roar every time i turn it on.Who would have known this June/December romance would be so good! Class D amps on vintage speakers,this is food for the gods.

After a search, here's a post from another thread for what it's worth:

"I know of 2 very committed Mcormick DNA-500 lovers that have both opted to go to Spectron Musician III SE amps."

I guess everyone doesn't think the DNA-500 destroys Class D. :)
Keep in mind that audiofreakgeek is a Nuforce dealer and his comments must be taken in that context.

A dealer disclosure is essential when discussing products in which there is financial interest.
Nobody has mentioned the NAD M2,anyone had a listen to this one?
"Nobody has mentioned the NAD M2,anyone had a listen to this one?"

No but it is on my want to hear list.

Realize that this is a true digital integrated that includes a Class D power amp and is all digital in front of that (except for analogue inputs that are converted to digital internally). So this is a slightly different but related beast.
How about the ARC DS225 or 450?
Hello Kijanki,

"It is often said that Icepower sounds good only with linear power supplies. On the other hand newest linear class AB amps from Jeff Rowland (one costing $46k) use switching power supplies. "

You are correct, Jeff Rowland developed his own highly regulated switching power supplies with PFC and show that this power supplies is the future for class A or A/B, ss and tube amplifiers.

We also have developed in 2008, very powerful swtiching power supplies with PFC abd fully regulated but we use it in our pro audio projects only as price/benefit analyses of moving it to Musician III with its linear power supplies show relatively little sonic benefits versus substantial price increase to cover the transition.

Refarding all other switching power supplies I am aware of - some like NuForce in their Ref 18 amplifier started to add electrolitic energy storage capacitors, This, if done right, should substantially improve current delivery and peak power delivery which in turn should improve sound.