Too Much Power?

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

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

BO said...

Most people have no idea about the properties of an amp, source, cable, loudspeaker etc." 

I am not sure what "most people" know about the above.... I only know what I have experienced in some 60 years of making and listening to acoustic music... Live and recorded alike.

In the last few years, I gradually formed a more than positive opinion of certain class D amp designs, particularly those based on NCore, Pascal M-Pro2, and even some classic ICEpower. In particular, I have experienced the staging, imaging, and timbral resolution and emotional engagement of NCore to be exceptional.

Have I listened to Pass and Krell? Sure, many times.... Really nice amps... Yet this far I have prefered the aforementioned NCore and Pascal based amps.... But I keep an open mind... The future is, of course -- in the oft unpredictable hands of Gaia *Grins!*

G.

Hi Northernfox, one option, somewhat less expensive than Veritas, are the Theta Prometheus monos. Like Veritas they are based on the full NCore NC1200 modules, but instead of the NC1200/700 SMPS, Theta has designed its own power supply... I believe it be a toroidal design. Unless things have changed, Prometheus may be priced at $9K / pair.

I have not tried them... Given the different power supply design, they are bound to sound a little different from Veritas, but I do not know if I would necessarily prefer one over the other.

Saluti, G.

Hi Noble, not sure which World BO1972 may be busy trying to depress, but it isn't my World for sure... Whenever I get a wif of an underappreciated-narcisistic-messianic pronouncement anywhere, and in any human domain, I cringe.