Mytek slams Hypex in Stereophile Amp Review

addyson :

Well, I don’t own stock and won’t make money either way, but that kind of attack in the press is really not one I am used to.

Anyone have experience comparing Pascal vs. Hypex amps?

The Duntech Sovereigns are specified as being 3 to 4.5 ohms. That is well within what should be the Hypex’s comfort zone.

Not if there's a -50'-60' degree negative phase shift also at 3ohms, then the amp could be looking at nearer 1ohm.

Mytek ultimately chose an amplifier module from the Danish company Pascal

And this could indicate Pascal get them from China and mod them. As are Red Dragon and Rowand Research

http://www.pascal-audio.com/amplifier-modules.html

http://www.theaudiobeat.com/equipment/pics/jeff_rowland_continuum_2_large_inside.jpg

https://www.reddragonaudio.com/products/s500?variant=969867425

https://www.stereo.net.au/forums/uploads/monthly_2017_05/Capture.JPG.eecf146fa0c42ac376beb2799afd581...

Cheers George

Not if there's a -50'-60' degree negative phase shift also at 3ohms, then the amp could be looking at nearer 1ohm.

Not exactly how this works, but yes, large phase shifts mean high currents near zero volts. Hard for most amps. Would be nice if we had impedance graphs for the Duntechs. 

Not exactly how this works, but yes, large phase shifts mean high currents near zero volts. Hard for most amps. Would be nice if we had impedance graphs for the Duntechs.

There is a formula for it, on diyAudio somewhere, but as usual it was in my head while I needed it, but soon sieved out of there in a hurry, like rats on a sinking ship.

As for impedance graphs with -phase layovers, Stereophile is the only one to do this, but they never use the EDPR formula to give the real load the amp sees.

Only one I’ve seen do this is Miller Audio Reasearch Test Labs, when they did 3rd party Lab Report testing for HiFi News and Record Review, like they did on the Wilson Alexia, which managed an EPDR of just 0.9ohm!!!! in the bass.
https://www.absolutesounds.com/pdf/main/press/WA%20Alexia%20HFN%200313-4web.pdf

Cheers George

Not if there's a -50'-60' degree negative phase shift also at 3ohms, then the amp could be looking at nearer 1ohm.

Not exactly how this works, but yes, large phase shifts mean high currents near zero volts. Hard for most amps. Would be nice if we had impedance graphs for the Duntechs.

High current at near 0 volts is a lot easier than high current at higher voltages :) This might be why some of our customers had success with the Sovereigns, and we make OTL amplifiers.

Bruno Putzey is one of the top class D designers in the world and the Hypex modules are extremely competent. I highly doubt that they could not drive the Sovereigns. Now the modules need power, and if someone put them in a box that did not give the modules the power they need, that's another thing altogether! I'd be a bit nervous blaming the performance of the amplifier on its modules until I knew more about how well its power supplies worked!