Class D = Trash?

Erik,

I believe Krell FPB does not have a fully regulated power supply from front to back.  The KRS series does and maybe the Krell master reference as well.  Though to my belief that power supply is one fundamental aspect of amplifier design, but it is only one of the many aspects which make the amp sounds good such as topology and devices being used, implementation to name a few. But I digress since we are talking about class D so let us switch (pun intended) back to class D channel shall we?

@h2oaudio - Since I'm not that big a Krell fanboy, it is VERY likely I got the models/series wrong. :)

I only wanted to point interested parties to examples.

I am going to start another thread I think, for people who LIKE class D. :)

Best,

E

Well, again, not a big deal, but this from a review on the Krell FBP:

The output stage in all FPB amplifiers employs a free-floating feedback arrangement wherein ultra-fast regulators independently monitor the output stage and respond to the smallest drop in current or voltage with regulator response that is all but instantaneous.

Bit of useless marketing/design trivia for Krell fans. :) Of course, this is only the output section, but it would be VERY weird to regulate the output but not the inputs, since the latter is much cheaper to do.

Best,

E

Hi Henry,

     Thank you for taking the time to respond in such detail to my question and stating that you do think there's a direct relationship between an analog power supply and good bass response in an amp. Given your praises of regulated amp output voltage, which the switching mode has but which the analog power supplies typically lack due to expense,  I would have thought the relationship between an analog power supply and good bass response would be less direct. However, I'm fairly certain it's best to defer to your knowledge and experience on this matter.

     It's very interesting and encouraging to know that you're continuing to explore the potential of the somewhat newer class D power modules such as the Hypex NCore 400 modules along with corresponding Hypex switching mode power supplies.  I would be very interested to know if you discover varying performance levels between these modules paired with the various Hypex smps (NCore 1200 and 600 smps) and the NCore 400 modules paired with your own analog power supply.

     Strictly from my subjective viewpoint,  the most obvious differences I've noticed between using class D and various class A/B amps(Adcom, McCormack and Aragon) in my system are improved bass response, a reduced noise floor,  increased dynamics (especially on content recorded in hi-res 24/96 format), increased detail and a more neutral sonic character in general.  
     These benefits were clearly noticed on the first 2 class D amps I owned (Class D Audio SDS-440-CS and Emerald Physics EP-100.2) and these qualities are even more clearly noticed on my current class D amps (D-Sonic M3-660-M).
      Just to be clear, I was not offended with anything you said and agree that there is no absolute in this hobby.

Thanks Henry,
 Tim   

@guidocorona ,

1) Once a class D is broken in is it stable from then on; or will it need to be broken in again if it sits idle for an extended period? (Actually any well-informed reader’s input on that would be much appreciated.
2) I just bought a used Audiosource on eBay for $60. When do I get my 500 Valium? Can I get more if break-in takes longer than 1,500 hours? Is this an honor system?