New Bel Canto REF600M using NCORE

Audio Vision in San Francisco is selling the REF M600 at a discount at $4590.00 a pair and Underwood Hi-Fi will also discount. Sure like to see the engine under the hood and look at John's latest magic he does with his added power supplies. Not sure if the Ref M600 is the latest NCore NC500
but Guido will confirm with his future review.

Hi Audiozen, I'll try to find out what NCore module there is inside REF500. As for power supply, I have heard that each mono chassis sports its own Hypex NC1200/700 SMPS, which is powerful enough to support even the full blown 400W 38A peak current of NCore NC1200. This means that the 300W/8 600W/4 at 27A peak current can be supported with plenty fheadroom to spare.

On REF600, John Stronczer seems to have concentrated his design work on the custom differentially balanced input stage instead.


One useful feature of REF600 is the internal DIP switch to change gain from 27dB to 33dB.... This will be quite useful for use with lower efficiency speakers, such as the Maggie 3.7, and probably my own Vienna Die Muzik which has a bit of a wilding impedance curve.

G.

Hi Guido, very interesting your comment regarding the gain switch in the new REF600M.

As far as I know, the gain setting has more to do with the preamplifier stage than with the speaker load.

It sets how sensitive the amplifier will be, meaning how much voltage it will need at its input to obtain its rated power.

So, if you have a strong enough preamplifier, you can lower the amplifier gain and still be able to reach the device rate power, independently of which speaker you have connected.

The big advantage is that with lower gain settings, you maximize the signal to noise ratio.

I would like an even lower gain setting, as many new DACs have quite strong output capabilities nowadays. The new Benchmark AHB2 has three gain options, for example, with the lowest being 13 dB.

I'm not 100% sure, but I believe that for the REF600M the gain option depends on the Hypex module, so there's not much John can do in that respect.

Rgds,
Sebastian

Sebastian, gain option is featured on the official product specs listed on the device page. I suspect that if the switch were a no-op because of some inherent NCore limitations, Mr. Stronczer would not have bothered with it... But I will ask him directly when I talk to him next.

Worth pointing out that a gain setting is available on other NCore based amps... E.g. Merrill Teranis, and my own Rowland M925.

In the case of Teranis, to optimize interoperability with my Vienna Die Muzik speakers, gain was increased to 29dB with no ill effects... On the contrary... Noise level did not grow at all, nor distortions were introduced... But that's the topic of a different thread.

G.

Spoke with John Stronczer, he confirmed that REF600 has an internal 27/33db dip switch. According to him, the higher gain may be particularly indicated when the amp is driven directly from some lower gain DACs.

John has also confirmed that each REF600 chassis sports an NCore NC500 amplification module, in addition to an NC1200/700 SMPS.

Eventually, I hope to be able to listen to the creatures in my own system.

G.