The crew at Hypex has been
making class D amps for a long time- lead designer Bruno Putzeys designed the "Universal
Class D" topology at Phillips, and Hypex licenses it for use in their own
products (Phillips owns the patent). Hypex has had a successful run with this
technology, my own amplifier uses their 400W (into 4 Ohms) boards, and Iíve
been very pleased with it. As time rolls on however, improvements have been
identified and Hypex has released a new, higher-end variant on class D,
designated "NCore". The UCD line is still active and Hypex has a variety of
interesting plate amps, DSP, and other components with and without amplification
attached, all very well engineered.
My good friend decided that he wanted more oomph than his receiver was providing and because his speaker setup matched his space so nicely, he decided to go with an amplifier upgrade to achieve that. With a box of doughnuts in hand, he and our mutual partner in crime came around to my workstation... errr... kitchen table with a couple boxes of parts beyond the doughnuts, including the Hypex Ncore 400. The Ncore 400 delivers up to 400W into 4 Ohms, though that is dependent upon the power supply. These boards are intended for DIY'ers and are meant for use with Hypex switch mode power supplies. Normally the Ncore 400 is used with its sister supply SMPS600 -- the combination fit nicely to make compact monoblocks. In some cases alternative supplies may be used; for example when a compact stereo amplifier is desired, requiring a single larger supply (the SMPS 1200). We wanted a stereo amp, and it took some extra efforts, we had to do a fair amount of splicing and careful routing to achieve a good setup with this modification, but in the end all worked out well.
This thread and this thread within AudioCircle discussion board contains the diagram used for cross-coupling from the intended SMPS600 to the SMPS1200.
Notes on switch mode supplies:
We carefully routed the input, speaker output, and power supply wiring around the boards, to ensure low potential for noise pickup. Between the twisted pairs and shielded input wire, we had no noise issues whatsoever.
Power supply wiring was pretty simple, utilizing high-current push-in connectors for the multi-wire junctions. These connectors were nice to work with and made very solid connections with tinned solid core leads. The alternative would have been terminal strips where space was at a premium, or wire nuts which have other shortcomings. Multiple twisted pairs were used for the main rails to keep radiated fields and wiring harness inductance to a minimum, and the lower current, lower voltages were hooked up as made the most sense from a layout perspective. An amp like this has multiple connections from power supply to amplifier circuit, to drive not only the main transistors responsible for the output voltage, but also to drive the input circuitry and class D oscillator/etc. Some class D amps, including the Hypex UCD, have these connections as optional- they can derive the needed voltages onboard from the main rails. The single main supply arrangement is convenient but best noise and amplifier performance is achieved by having multiple well-regulated supplies for all needed voltages. While itís hard to tell from the picture, we used as much of the case height as possible to avoid interference in the power supply wiring, and got everything squeezed into the space available without issues. Fortunately these are DC supplies, not AC wiring, so we can allow for relatively tightly-bunched bundles as shown. Often these are routed in one overall bundle, but I prefer to keep things a little separate. The mute switch is on the back panel, to maintain the clean look of the faceplate.
All was well upon hookup- and the overall character was similar to my UCD amplifier- which is a very good thing, as my UCD is an excellent amp. We enjoyed some DVD concert content and CD music, but as this wasnít my amp it was not to stay in my home for prolonged evaluation. Because it was only here for a short time I wonít endeavor to compare the sound of NCore to UCD, though user reviews are very positive online. The amp is pulling very smooth, clean, powerful sounding service in my friendís rig and heís happy with the upgrade so weíre calling this one a win.
2. Switch Power Supply: Hypex SMPS1200/400 - 1 MOdule
3. IEC Input Plug: Furetch FTECH-65010 15A 125V/ 10A 250V AC
Inlet Male, Rhodium, solder lug
4. XLR Connectios: Cardas CM F XLR, Chassis/PCB Mount, XLR
Jack, FEMALE . 2 Connectors
5. Speaker Binding Posts: Furetch FT-809 Torque Binding Posts
- Gold Plated 2 pairs
6. Case: RE2507-NC enclosure for 2 channels Hypex NC400
(Mounting re-drilled manual -
7. Mute Switch: SPST Mini Toggle Switch
8. Custom Molex Module for NCore400:
(1) Molex header - Mouser Part # 538-43025-1200
(2) Molex Wire Housing - Mouser Part #: 538-46235-0002
(3) 20 AWG insolated solid connection wire in Black,
Blue, Red, Green, White, Orange and Gray
9. Wire: Hookup wire - DH LABS Silver Sonic 14 AWG. BLACK and
RED Hookup Wire
10. Amplifier Stands: Four quantity Penn-Elcom F1696 rubber cabinet
foot 1" D x 1.25" H.
Amplifier Module Features
Voice: +31-(0) 50-5264993