Pilliod Audio mono amplifiers with Hypex UCD400 HxR

I just received my new Pilliod Audio mono amplifiers with Hypex technology and wanted to post some photos and see if anyone else had experience with these. I purchase them to be an upgrade 
to my Auralic Merak mono amps. The Merak amps were about as refined and open as anyone could ever want so this is a tall order to fill.  My initial findings are they they're are at least as impressive but I will know more after the burn in. My source is a PS Audio Directstream DAC and Wyred 4 Sound STP-SE mod 2 with upgraded over and above the mod 2 upgrades, caps, regulators, Kiwame signal path resistors, Sparkos Labs descrete 3062 opamps and a few more that I will not mention. All playing from a Mac mini with upgrades and a separate regulated power source. 
Very pretty case, and layout. Looks like they are NOT going with the Hypex PS but bulding their own linear supply.

Also interesting they went with the UCD instead of the latest nCore power amp. I’ve not heard either, but really want to listen to the nCore to compare against the ICEPower I currently use.


By the way, I think you can get Kiwame discounted if you look for KOA at Mouser. Last I looked the oddly speced resistors were identical.


These have a conventional power supply. Not the switching power supply that is normally used. These are the UCD400 HxR amps and the power supply board is
marked Hypex as well. I believe that the regulation is on the amplifier module. The sound pretty good so far. I would like to figure a way to mount the Sparko's labs SS3602 descrete opamps in place of the surface mounter LM4562 opamps that are mounted on the under side of the amp module. 
I have the same amps. The UCD 400 HXR with the UCD HG (non switching) power supplies.
Running them off an SP10 preamp into Analysis Omegas.
They are incredibly powerful, dynamic and resolving. In some respects, they’re the best amps I’ve listened too. But, I get an occasional sense of glare at the upper frequency extreme. It can be edgy and a little annoying at times. Are you feeling that too? I’m not sure, it’s recording dependent perhaps.
i will be comparing to a pair of VTL MB 450s soon which will be a nice comparison.
I spent a couple hours going back and forth w my Borbely class A mosfet amps. 
The hypex is less rich texturally. It's the only way to describe the difference. Not subtle at all.  Despite the high headroom on the UCDs the richness of the wonderful Borbely amps can be more engrossing. 
Will await the VTLs....

I have had extensive experience with Sparkos op amps. These op amps are absolutely awesome, but it’s important to know that they do require a significant amount of voltage and current to sound good. It’s easy to starve these op amps and they will sound lackluster. They run in Class A (not as much as the Burson V4), but enough where you need to heatsink the regulators. You also need a significant amount of main power supply capacitance for the Sparkos. Not sure if this amp has that on the power supply. Since it’s only powering LM4562 op amps, it may have very little capacitance for the pre-driver circuit. The big caps may be only for the power output section.

BrownDog sells a vertical adapter for DIP8-to-SOIC,


but I don’t think you are going to have the space to place this. The LM4562 is a dual-channel SOIC (SMD) op amp and you have limited space. (maybe you can try to flip that main amp heatsink upsidedown (but I suspect it’s bolted to the case for heat transfer).

The very best non-discrete op amp I know is the AD797, but these are single channel and still require that vertical single-to-dual adapter above. If you wanted to try upgrading the op amp, the best I see is something like the AD8512-BRZ. It’s also a dual-channel SMD op amp and has decent noise/distortion/settling characteristics (not nearly as good as the AD797). Though, the default fallback is always the OPA2132.