General Asylum

RE: AFAIK, Herv� Del�traz believes solid state output stages should not use multiple driver pairs

96.25.74.167

rick_m

In Reply to: RE: AFAIK, Herv� Del�traz believes solid state output stages should not use multiple driver pairs posted by John Marks on June 27, 2014 at 12:56:23

Thanks for the link.

I especially liked the bit about matched transmission lines not having losses... Would that it were true! And I'm not sangiune about lumping jitter with TIM into one puddle as "TD" just because "time" has something to do with both. Guess that's marketing for you.

Regards, Rick

Follow Ups:

I think that Herv� is sincere--and he is a graduate engineer - John Marks 09:11:43 06/28/14 (2)
I have the luxury of being able to shrug and say (as I often do) "We don't know whether this item sounds good BECAUSE of a certain design feature or IN SPITE OF that design feature."

And I have to assume that darTZeel departed from its own professed orthodoxy when it made its monster monoblock amps--those cannot have just two output transistors per channel... .

JM
- some information..... - mikel 15:33:59 06/28/14 (1)
  I owned the darTZeel NHB-108's for 6 years, and now own the NHB-458 monoblocks.
  
  some info I have from darZTeel on the monoblocks;
  
  > > > > > > --no contact, nor switch, relay whatsoever in the signal path.
  
  --no negative feedback in the input stage.
  
  --no negative feedback in the output stage.
  
  --there are "only three (3) discrete junctions (transistors) in the signal path per polarity, whereas in the 108 there are 6.......in terms of measured distortion, figures are similar as for the NHB-108. THD is kept below 1% audible threshold, while the most critical temporal distortion is completely absent from the equation".
  
  --the main AC fuse has been replaced by a thermal breaker. < < < < <
  
  this is from Fremer's review of the NHB-458 monoblocks;
  
  > > > > > > > "Total harmonic distortion is specified at less than 1% from 7Hz to 77kHz. That's fairly high in today's solid-state world (though across that bandwidth it's pretty impressive), but Herv� Del�traz claims that THD "has nothing to do with musical performance." Like the darTZeel's original NHB-108 integrated amplifier, the NHB-458 has a zero-feedback, true open-loop output stage, so there's no output-impedance compensation (ie, Zobel Network). The specified output impedance is less than 0.28 ohm, 20Hz�20kHz.
  
  Del�traz cautions that the NHB-458 is not suited for speakers with a nominal impedance of 1 ohm because of its low parts count: despite the high power, there are only four transistor pairs in the output stage." < < < < < < < <
  
  these amps are quite amazing in terms of ridiculously low noise floor and lack of distortion. yet they don't sound like solid state or tubes, they sound like music.
  
  mikel
  - Fremer's review of the NHB-458's (Open in New Window)
  - Thanks. (nt) - John Marks 11:22:20 06/29/14 (0)
    jm

Post a Followup:

FAQ

Post a Message!

Forgot Password?

Moniker (Username):
Password (Optional):
	Remember my Moniker & Password (What's this?) Eat Me
E-Mail (Optional):
Subject:

Message:	(Posts are subject to Content Rules)

Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:	Automagically notify you when someone responds.

To view your new posting or follow-up, click on the RELOAD or REFRESH button on your browser.

This post is made possible by the generous support of people like you and our sponsors:

Crux Audio