2. amps-preamps
  3. 128835-12239

Too Much Power?

I have a question that relates to the maximum power output of new Bel Canto Ref 600M monoblocks, which I am considering to replace the Audio Research 150.2 SS amp I am currently using in my main system. (Yes I am another of the "lunatic fringe" who enjoys the results of good quality Class D.)

The Ref 600Ms are  based on a Hypex Ncore module, and are stated to produce a maximum power output each of 300W into 8 ohms.  My question  is whether this can prove to be a problem in powering my Focal Alto Utopia Be speakers, which are stated to have a "maximum" power handling capacity of 250W each (their nominal impedance being 8 ohms).

I listen to mostly classical instrumental and vocal music and other acoustic instrumental music, and do not listen at particularly loud levels:  the ARC 150.2 is rated at 150W per channel into 8 ohms and it has never in 10 years appeared to go even close to its limits; I rarely if ever  turn up the volume control on my ARC LS-25 past the 11:00 o'clock position.

Should I be concerned about the Bel Cantos damaging the Utopias, given the speakers' 250W per channel maximum capacity and the 300W per channel output potential of these amps?  The Be tweeter and other components of these speakers can be very expensive to have to repair, not to mention the inconvenience and aggravation which I really do not need. 

Thanks in  advance for any thoughts or advice on this.

northernfox
guidocorona
4,298 posts
 


Congrats about your new Bel Canto REF600 monos!

I am quite familiar with amps based on NCore technology, owning a pair of NC1200-based Rowland M925s, and having also had in my system and written about the excellent NC1200-based Merril Veritas monos and the NC500-based Merrill Teranis stereo.

Like most everyone already said, you should not be concerned about too much power from the amps.... clipping is the biggest danger, and the significant power reserve in the 27A per side should avoid it, unless the house cat started to play with the volume knob on your preamp *Grins!*

Nor am I concerned about REF600 not being able to handle speakers with low or variable impedance: REF600 has a damping factor of 1000, and should be able to power the majority of speakers on the market today without breaking a sweat.

Be patient with break-in.... Right out of the box, NCore amps are listenable, if less than delightful, but after 48 hours of making music they become quite reasonable. Full break-in should range between 600 hours and just over 1000 hours of chewing some signal. Expect some wildish fluctuations in performance during the first several hundred hours... Nothing to worry about: eventually, any bandwith limitations, excessive brightness, darkness, hardness, transient limitations, etc... all disappear, and the amps will bring you their magic.

You can leave the amps on 24/7 unless the weather forecast promises thunderstorm.... Power draw on idle is minimal... Power efficiency is between 85% and 95%, so even during full operations, the amp will be only moderately warm to the touch... And you will hardly notice their existance on your monthly electric bills.


To speed up break-in, feed them white noise when you are not listening to music, even during night time.... I use an old FM tuner tuned to interstation FM hash, with the preamp volume knob at lowish volume.

As far as I know, REF600 are based on the NC500 module, which is a slightly simplified version of NCore, delivering approximately two thirds of the current of the full NC1200 module. It is unlikely that after break-in is complete you will still experience any anomalies in the form of slight haze, bloat, or mild hardness at high SPL. But if you did, it would be a symptom of the modules approaching saturation. If this happens, change their gain from the factory default of 27dB to the 33dB by operating the setting inside the chassis... I had to do something similar with Merrill Veritas to get best results on my relatively large and demanding Vienna Die Muzik speakers.

You can download the REF600 manual from the page below:

http://www.belcantodesign.com/home/eone/ref600m-amplifier/

Saluti, Guido

northernfox OP
26 posts
 
Guido: Thanks for the usefull tips on break-in and related issues. I have observed that you have a lot of knowledge about and experience with quality Class D.

One further thing that occurs to me is if you have any thoughts in how the Bel Canto Ref 600M compares to the Merrill Thors.

My current plan is to do a final audition at the dealer’s in early April, and if that goes well to then buy the amps.

Steve
wolf_garcia
6,708 posts
 
The actual amount of power being used is much smaller than you might think if your speakers are relatively efficient. Having reserve power for gigantic crescendos or that DJ Bass thing the kids like is fine, but I think the general quality and specific tone generated by an amp is where the mojo is, and buying extra watts can be a waste. I have a friend who owns a pair of mondo Pass Labs amps and damn if that V.U. needle ever moves. Great amps anyway…in a interview with Nelson Pass it was noted that during listening to one of his First Watt things that was hooked up to some sort of output metering device, the interviewer noted the amp barely did more than a few watts at fairly loud levels. I like that sort of thing.
guidocorona
4,298 posts
 

Hi Northernfox, as far as I know, the Merrill Thor monos are based on a form of Hypex UCD module, which from an architecture point of view sits below NCore.


Having said the above, the power conversion module is but one factor in the performance of a class D amp.


I have had no experience on Thor at all.... But if you have the opportunity, it might be worth while listening to them. You might want to contact Merrill and see if he can send you a pair to audition in your system.


BTW, what is your allocated budget for this amp project?


Saluti, Guido

 


 

northernfox OP
26 posts
 
Giudo:  With Bel Canto Ref 600Ms ( or with Merrill Thors) I am looking at around $4,500-$5,000 stated price per pair.  I did briefly consider Merrill Veritas;  but at the stated price of $12,000 per pair, I really doubt Veritas would provide enough upside difference for my situation to justify over  double the cost.  

Steve
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