2. amps-preamps
  3. 185086-106432

Should I steer clear of class D amps

I’m finally upgrading my amp. I currently have an Onkyo TXNR 636 which has served very well but it’s now the weakest component in my system.

I’ve a budget of up to £1200-£1300 and been looking at the NAD C3050.

I was initially drawn to the NAD C3050 when I saw the VU meters but these are not deal breakers if I can get a much better amp without them, but I really do like them. I spoke with a dealer and he mentioned all NAD amplifiers are now class D and that’s now where I’m stuck procrastinating my purchase. My understanding was class D never really took off, despite the power efficiency due to the HF noise caused by the PWM. Times change things improve but I can’t find much about how they have mitigated this, in fact an article in EETimes refers to how the tests performed for THD etc are quite irrelevant in a digital amp and quoted figures may be very different in real life. In essence, the way of testing makes them look better than they are. This may be true but do they sound good? We all know vinyl is technically an inferior medium but I certainly prefer it’s sound.

I am listening to classic/ heavy rock and a mixture of lossless streaming from a NAS into a Cambridge Audio CNX V2 and vinyl off a Technics 1500C with a Pro-Ject DS phono stage all into monitor audio bronze 5s. 
 

I need a new amp. I need slapping out of my indecision but it’s not an insignificant amount of £££ and I want to get it right. Should I stick with AB ? My electric bill can’t withstand class A or valve regardless of sound quality. 

Also what’s the thoughts on NAD in general, I’m my youth they were good amps, but then so were Pioneer. 
 

nosleeptilldownload
seanheis1
634 posts
 

Class D amps need a tube preamp or a solid state Class A input stage that adds 2nd order harmonic distortion to the signal. Linear power supplies can also add 2nd order harmonic distortion. 

If you get a stock module from Hypex or Ice Power with the Hypex or Ice Power stock switching power supply...and combine it with a preamp that is adding nothing to the signal path....such as a Benchmark DAC or Benchmark Preamp...you will get that sterile lean Class D sound. 

Class D is sounding much better because brands such as Jeff Rowland have figured out how to add the right distortion amounts to the signal path. I believe Jeff Rowland & PS Audio use old Ice Power modules....so it's not like the modules are necessarily sounding better....but the implementations are definitely becoming more musical.   

phd
1,331 posts
 

It's all about good sound and not what class it's in. In all Class designs there are good and bad sounding amps. You just need to try before you buy.

jaymark's avatar
jaymark
521 posts
 

I had some old class D amps and never stuck with them.  The LSA Voyager GAN 359 wpc that I had modded sounded nothing like my old class D amps.  It was light years better.  I have Pass Labs X250.5 and X150.5 amps, Parasound JC1 monblocks and Ampzilla monoblocks.  The Voyager GAN perhaps gives up a little liw end grunt to my  solid state amps but bests them all on midrange clarity and upper end extension.  They are all excellent amps.  The SS amps have fine midrange clarity and extension as well.  These newer class D amps are not your fathers class D amps.  

tweak1
3,701 posts
 

I too have owned quite a few class D amps over the decades, including the PS Audio M700s, which were decent but not enough umph for my big room. The 2 that remain are the EVS 1200 dual mono single chassis amp, a Ric Schultz (Tweak Audio) effort based on dual IcePower AS 1200 modules, (same modules as PS Audio uses in their M1200s) but with a ton of his pixie dust sprinkled throughout. I also have a LSA Voyager Gan350 (dual mono GaN fet boards) that I preferred at the time, but when reconfiguring my rack from vertical to horizontal I managed to take out a module and have not yet gotten it fixed, but the 1200 sounds so incredible after a complete cable change that I am quite content, for now

hth

atmasphere's avatar
atmasphere
12,124 posts
 

Class D amps need a tube preamp or a solid state Class A input stage that adds 2nd order harmonic distortion to the signal. Linear power supplies can also add 2nd order harmonic distortion. 

These statements are false. I can imagine some amps (regardless of class of operation) for which adding a tube preamp or the like is the band-aid needed for their dryness. But if the amplifier is properly designed it needs nothing of the sort. The second statement is just- wrong.

More to discover