Having previously owned Class-A/B amplifiers over the years from Cambridge, Carver, Parasound and Rotel, I've recent switched to Class-D and couldn't be happier. Have come to the conclusion that when properly designed, Class-D can absolutely hold its own against the traditional HiFi big boys. That said, there's still quite a bit of hesitation and resistance to Class-D from the buying public. Could this be due to the HiFi demographic primarily being middle-age guys who are generally 'set in their ways'? Has Class-D not yet or only recently made advancements which rival the industry standard A/B topology? Are the larger, heavier amps simply 'better' and thus more worthy of our hard earned cash? Opinions of course are always entirely subjective...what are your thoughts?

Edited October 28, 20187 yr by HammondRye
Removed a silly race reference.

Kii Three and Dutch & Dutch 8C are examples of this type of amplification when married to excellent DSP.

For critical listening, i have tried and made the switch to a class D board and i'm happy with it.

The last AB amp has gone to gumtree.  No regrets.

 

To my ears, some of the cost effective class D amp boards have gone past (way past) the old AB icons (NAD 3020, Audiolab 8000a).  From the threads involving class d tweaks and comparos,  the cheap and cheerful class d amp boards started to come good a few years ago.  The newer and higher powered stuff isnt that cheap but alot of feedback strongly suggests that they are even better sounding.

 

While i'm not in "need" of any hifi - i might go and say hi to Hydrology as i go past there quite often.  Might be a good / bad idea to see what i dont "need".    I was there last to hear the olympicas.

Edited October 28, 20187 yr by hifix

Could be middle aged men....not sure what 'white' has to do with it.

56 minutes ago, Ugly said:

Could be middle aged men....not sure what 'white' has to do with it.

Excellent point. That shouldn't be in there.

I bought a primare to test this out and im totally on board .. classD or similar will prevail, dragging along stalwarts with it. .. still sold it and went back to my Sansui though so go figure

It’s the synergy with the rest of your system, I believe most want to play safe and hence go with tradition.

Synergy, I love that term

I'm enjoying both :)

Bi amping, Class D for low frequency and Class A/B for high.

24 minutes ago, Musician said:

It’s the synergy with the rest of your system, I believe most want to play safe and hence go with tradition.

Yeah.  it's still down to the whole system of course.

Have been playing with a NAD C338 which is rightly described as a D hybrid.  It's more of a sound processor than just an amp given its range of inputs. My system is mostly older gear so just sticking it inline is not the best test.  Initially thought it a bit bright but it can be calmed down.  Made me realize how I'm adding detail to my older amp by way of DAC and Phono.  It has Chromecast and WiFi which I'm struggling with. My troubles are probably due to the whole internet here in Tinytown being down and having to go through mobile data. I don't think it's made for that.

Essentially I'd say 'fine if it fits your needs'.

 

11 hours ago, HammondRye said:

Could this be due to the HiFi demographic primarily being middle-age guys who are generally 'set in their ways'? 

An excellent example of a question that contains its own answer

I also use a Class D amp daily now.  I also use valve class A/B ultralinear, and SET, and even transistor class A/B.  So I figure that probably helps me to not be biased (pun intended).

 

I know I am sometimes reluctant to say, on hifi forums, that class D is good.  Definitely a lot of prejudice around.

 

I know that yesterday, I had a guest around to listen to the new remastered Pink Floyd DSOTM.  He couldn't see the amp, and I didn't tell him until later what we had been listening through.   He never realised anything was "wrong"  

Edited October 29, 20187 yr by aussievintage

My 'conversion' to Class-D started with a DALI Katch as I was blown away with its fine details and musicality. No doubt this largely due to the overall development of that svelte little unit but it definitely intrigued me none the less. To that point, I soon upgraded my entire system to DALI's top end standmounters and Gato's new integrated to pair with them. The Gato replaces a Parasound A-A/B Integrated and without a doubt pulls ahead in finesse, refinement and sonic sophistication. For the record, Gato currently doesn't have an Australian distributor and they were happy to ship to me directly. I've written a full review of the DIA-250S which is attached just below...

Gato DIA-250S Review.pdf

Edited October 29, 20187 yr by HammondRye

I have moved to class D out of necessity (space confinements).
Its a reasonable one, Project Maia DS2. It has plenty of guts, but still find the sound a little more lean/analytical compared to the A/B I have owned in the past.
That said, with the right speakers, it is quite decent, and am glad to have found something this capable in its size.

Edited October 29, 20187 yr by Andre28

Hi all

I'm a bit new to this idea or concept of Class D amps as I've always had class AB amps. I've done some reading and whilst the theory goes over my head a bit the idea of smaller cheaper etc appeals.

 

Please tell me though, how do these amps handle low impedance speakers ?

My current VAF i93s average about 3 ohms and are quite difficult to drive well - not inefficient but a difficult load for some amps.

 

Cheers

Des

Edited October 29, 20187 yr by Desap
mistake

3 minutes ago, Desap said:

Hi all

I'm a bit new to this idea or concept of Class D amps as I've always had class AB amps. I've done some reading and whilst the theory goes over my head a bit the idea of smaller cheaper etc appeals.

 

Please tell me though, how do these amps handle low impedance speakers ?

My current VAF i93s average about 3 ohms and are quite difficult to drive well - not inefficient but a difficult load for some amps.

 

Cheers

Des

Some do, some don't. 

 

Class D amps are no different to Class A, Class A/B, etc. There's good ones and some bad ones. Dollar for Dollar, the good ones are likely better than middle range Class A/Class A/B amps for most speakers. At the very top end, however and when driving very difficult loads, Class D may have a way to go. Key problem is the switching frequency, combined with the output filter. That said, in general, most are improving. Like all such things, you really should try out a few different amps with your VAFs. The i93 is a wonderful speaker and deserves excellent amplification. DO NOT buy on some else's suggestion. You must listen for yourself. 

 

Below are the measurements of three amplifiers:

1) An older, poorer Class D amp (and part of the reason why Class D is reviled by many - this thing should not have made it to market).

2) A newer, very high quality Class D amp (from the same manufacturer).

3) One of the finest Class A/B amps available.

 

1) https://www.stereophile.com/content/bel-canto-evo-2002-power-amplifier-measurements

2) https://www.stereophile.com/content/bel-canto-eone-ref600m-power-amplifier-measurements

3) https://www.stereophile.com/content/boulder-amplifiers-2150-monoblock-power-amplifier-measurements

 

Pay close attention to the frequency response graphs and square wave pics.

 

So, a good Class D can be very good indeed. IMO, a really good Class A/B is probably a little better. For now.

Nord seem to have set the standard for cost effective quality class d.

A nord one up is close to half the price of the bel canto ref 600 with exactly the same amplifier module and power supply and a better input buffer module.

You can also carry it under your arm.....

I went class D with my easy to drive speakers. $175 B&O ice module sounded really good. Dead quiet background, no hiss from the speakers, amps don't get hot & small.

 

Down side was the input impedance being very low and if you ever damage the board it is impossible to figure out how to fix it. 

I used very long time PMC DS-001 Mono .very good dark resolution.

A great sounding Class D amp I had the opportunity to listen to was the Rogue Audio Sphinx (V1) and their Pharaoh integrated amplifiers, both running Hypex modules (Class D) for power.and a tube for line stage. One of the most musical and powerful amp I have ever heard for the money. If the Sphinx had been available in Australia, I would have put my money down and be happy with it especially for their reputation in making Dynaudio speakers sing. And by the way, I am way past middle aged: more a Baby Boomer. 

3 hours ago, Zaphod Beeblebrox said:

So, a good Class D can be very good indeed. IMO, a really good Class A/B is probably a little better. For now.

 

agreed.

i've played with the jeff rowland 201 monoblocks which bored me to tears but the cheaper 102 stereo power amp was wonderfully musical.

ditto the rotel class d power amps and 1560 avr were zzzzz while the ab 1550 avr and some 15 series amps were excellent.

 

4 hours ago, Zaphod Beeblebrox said:

Some do, some don't. 

 

 

 

 

 

1) https://www.stereophile.com/content/bel-canto-evo-2002-power-amplifier-measurements

2) https://www.stereophile.com/content/bel-canto-eone-ref600m-power-amplifier-measurements

3) https://www.stereophile.com/content/boulder-amplifiers-2150-monoblock-power-amplifier-measurements

 

Pay close attention to the frequency response graphs and square wave pics.

 

So, a good Class D can be very good indeed. IMO, a really good Class A/B is probably a little better. For now.

Thank you for your informative response.

Cheers

Des

Following a few forum development threads of tweaked class d amp boards from ebay and critically with abit of help from forum members to get going, i'm now using a $22 delivered (was $19) amplifier board in my main rig.

I needed to swap the input capacitors and other components so i bought a few of these boards and "raced" them from a development perspective with one change at a time.

 

1.  Capacitor swapping - signal coupling & supply (went through a few here... a few wimas, epcos, vishays )

2.  Bootstrap cap swap (tried a few here - ended up using a SMD component in a through hole position).

3.  Bootstrap snubber (not all sounded the same)

4.  Output filter inductors

5.  Output filter capacitor

6.  Output filter resistor

7.  Getting the board to power down without a pop noise

8.  And a few other mods on the board (down to solder selection at different points... from 60/40 to cardas quad to jaycar).

 

it's gone slightly beyond $22 and despite it taking up alot of time, my only regret was not doing it sooner.  While the massive threads on audiokarma and diyaudio have slowed, it was nice to be part of a forum craze for awhile.  Strangely, i no longer have amp-upgrade-itis.

 

My old sonus fabers have never sounded better!

Edited October 29, 20187 yr by hifix

43 minutes ago, hifix said:

Following a few forum development threads of tweaked class d amp boards from ebay and critically with abit of help from forum members to get going, i'm now using a $22 delivered (was $19) amplifier board in my main rig.

I needed to swap the input capacitors and other components so i bought a few of these boards and "raced" them from a development perspective with one change at a time.

 

1.  Capacitor swapping - signal coupling & supply (went through a few here... a few wimas, epcos, vishays )

2.  Bootstrap cap swap (tried a few here - ended up using a SMD component in a through hole position).

3.  Bootstrap snubber (not all sounded the same)

4.  Output filter inductors

5.  Output filter capacitor

6.  Output filter resistor

7.  Getting the board to power down without a pop noise

8.  And a few other mods on the board (down to solder selection at different points... from 60/40 to cardas quad to jaycar).

 

it's gone slightly beyond $22 and despite it taking up alot of time, my only regret was not doing it sooner.  While the massive threads on audiokarma and diyaudio have slowed, it was nice to be part of a forum craze for awhile.  Strangely, i no longer have amp-upgrade-itis.

 

My old sonus fabers have never sounded better!

 

WOW!  R.E.S.P.E.C.T., hfx! 

 

Andy

 

7 hours ago, aussievintage said:

I know I am sometimes reluctant to say, on hifi forums, that class D is good.  Definitely a lot of prejudice around.

Heh.   

 

 

9 hours ago, aussievintage said:

 

I know I am sometimes reluctant to say, on hifi forums, that class D is good.  Definitely a lot of prejudice around.  

There are dozens of us...DOZENS!!!