Trials with Hypex NC400 based DENTEC DP-NC400-4-EXP Multichannel Amplifiers
Quick and Brief Conclusion:
The total sound quality with DENTEC DP-NC400-EXP was really wonderful and very nice fit for my multi-channel project, and it is definitely the top-ranked candidate for introduction into my system, even though it is really expensive.
Hello friends,
As I pre-announced here in this thread, Mr. Fujimoto, President of
SOUND DEN Sound Pro Shop, kindly visited my home yesterday with two of
DENTEC DP-NC400-4-EXP on his car.
DP-NC400-4-EXP has 4 (four) Hypex NC400 amp modules in it, and the amp and the wiring are very carefully fine tuned-up by Mr. Fujimoto and DENTEC people including cryogenic treatments and some of the thick pure silver wiring (I do not know the effectiveness, though).
DENTEC
DP-NC400-4-EXP (still not yet shown at their web site) is the new version/model of their
DP-NC400-4,
and the new DP-NC400-4-EXP has its "heavy-duty transformer plus large capacitors type" power supply (PS) in external PS Units. The one PS Unit supplies DC power for two NC400 modules, so, therefore, two PS Units are needed for one DP-NC400-4-EXP main instrument. This new concept and design of external PS Units will enable future reasonable(?) upgrade with possible new Hypex amp modules keeping the PS Units would remain unchanged, he said.
Before to try and listen to the sound of DP-NC400-4-EXP in my stereo 5-way (10-channel) multi-channel system, Mr. Fujimoto and I carefully listened to my reference sound with DAC8PRO in single DAC mode and ACCUPHASE E-460 integrated amp plus the renovated LC-network as show below. As described before, the RCA input into sub-woofers YAMAHA YST-SW1000 was achieved by ONKYO DAC-1000(S) through sync AES/EBU (CH1+CH2) connection from DAC8PRO.
We very carefully listened to the reference sound of some of
my Audio Sampler music tracks, and to his reference CD tracks recorded at their DENTEC Recording Studio. Then, he became much interested in the performance and sound quality of DAC8PRO (still only one in Japan, I believe) which he tried for the first time.
Next, I changed the connections at the SP Cabling Board into mutli-channel, multi-amplifier routes;
And we carefully connected 8 XLR cables from DAC8RPO into two of
DP-NC400-4-EXP, and also connected the 16 SP cables to the binding posts of two of
DP-NC400-4-EXP. He preferred that one to drive L-channel SPs, and another one to drive R-channel SPs, as shown below;
Now I set the software EKIO's configurations as follows which mimics the original LC crossover network of YAMAHA NS-1000;
and;
After careful listening sessions to the multi-channel sound of some of
my Audio Sampler music tracks, and to his reference CD tracks, we also tried the second EKIO configuration using 48 dB/Oct LR filters for the crossover of woofers to Be-squawkers at rather low ca. 475 Hz as follows;
and;
Using above described procedures, we carefully compared the reference sound and the
DP-NC400-4-EXP multi-channel sound in two different EKIO configurations.
Very regretfully, Mr. Fujimoto and the two
DP-NC400-4-EXPs could stay at my home only for half a day; even though we could have the intensive ear-listening sessions, no measurement session with REW and ECM8000 microphone was performed this time.
OK, now what would be my (our) impressions on the sound quality with two
DP-NC400-4-EXPs in my multi-channel system?
Here, I should not describe too much about our subjective impressions, but let me say that the total sound quality with
DP-NC400-4-EXPs is just amazingly nice and wonderful in comparison with my reference sound of single amp system.
We agreed that my reference sound with ACCUPHASAE E-460 is still also very nice, and two
DP-NC400-4-EXPs in multi-channel system gives audibly better responses of the SP Units (thanks to the elimination of the LC-network) and the S/N and distortion features are below audible level even in pianissimo small volume and also in rather large sound volume, just the same as in the reference sound.
We also found and confirmed that EKIO's crossover functionality is really wonderful and accurate with no deterioration of sound quality played by JRiver in 192 kHz 24 bit.
Also, thanks to the fine-tuned
DP-NC400-4-EXPs, together with the still very nice cabinet and SP units of YAMAHA NS-1000, the audible 3D sound perspectives and phase features are just perfect in any way; even when we moved, left and right, up and down, front and back, around my usual listening position, the nice 3D and phase features of the sound remained unchanged.
This is my first experience in listening to Hypex or Purifi Class-D amplifier(s), and I was really impressed by the sound quality of Hypex NC400, fine-tuned by DENTEC, especially the smooth, very clear and clean but not "dry", I may say a kind of "rich", sound which is my happy surprise, as I have been thinking of somewhat dry or crispy sound with Class-D amps including NC400.
I heard that the two of
DP-NC400-4-EXPs came to my home were already under the purchase order from one Japanese audio enthusiast, and this was the one of the reasons that they could stay at my home only half a day yesterday with careful handling of Mr. Fujimoto.
In conclusion, the total sound quality with
DENTEC DP-NC400-EXP was really wonderful and very nice fit for my multi-channel project, and it is definitely the top-ranked candidate for introduction into my system, even though it is really expensive.
BTW, Mr. Fujimoto looks to be much interested in DAC8PRO; I also told him that DAC8 Stereo is now also available, and I will soon send him the links
of OKTO RESEARCH as well as amirm's nice reviews
on DAC8PRO and
on DAC8 Stereo.