[ufokillerz]

2/3 of my amps rebuilt into new cases

[a.wayne]

Providing an update with some listening impressions now that I received my faulty SMPS600 back from RMA. I am now able to run both Dual Mono amps for the first time.

Before I move onto the difference with X 2 Dual Mono amps I will talk briefly about how things sound with X 1 Dual Mono amp powering both channels of my B&W 803Di2.

I have been running on one Dual Mono Amp for a few weeks now and felt I had a good handle on the performance of these impressive amps. With one Dual Mono I started to form an opinion that the NCore is one very truthful amplifier. It took me several listening sessions to figure out what I was hearing as compared to my previous amplifier setup. In the past I could always hear difference between "OK" Redbook recordings and Higher-fi Redbook recordings but now these differences are far more obvious. The NCore quickly puts bad recordings in their place and their is no way for them hide anymore. On the other hand, great recordings sound even better with me now being able to pickup on layers of the soundstage that I never knew where there. This is a well used Cliché I know, but it is what it is!

Whether these differences are the result of what seems to be a total lack of background hum/hiss/garbage I don't know but I am now able to hear a much more detailed soundstage then before.

With the single Dual Mono NCore setup bass quantity seems to be slightly less then it was before while using my Pass Labs X250 but bass quality, speed and definition goes to the NCore setup. It makes me wonder if the additional quantity of bass that I was  hearing with the Pass has to do with that amp injecting its sonic signature and the Ncore taking a far more neutral role in making music. This is interesting to me because it looked like driver cone movement was more under control with the Pass Labs amp in the signal chain then it was with the NCore.

In terms of how the NCore behaved when I began to crank the volume up towards the other end of the dial I could tell the hungry B&W's where wanting a bit more then what the single Dual Mono could provide. Although at no time did the NCore lose control, break up or sound distorted I could see the drivers were doing more work then I was comfortable seeing.


Fast Forward to a few days ago:

After what seemed like eternity I was finally able to hookup my system as I had originally planned all along which is running 1 X Dual Mono NCore amp per speaker.

With the new arrangement any previous lack of power has now been fully rectified. The best way I can describe the difference in sound can be summed up in one word: EFFORTLESS

Compared to running one Dual Mono amp the soundstage is now bigger, even more detailed and bass is rock solid given the same volume input. Driver movement is all but none existent even at law enforcement dispatching levels. I love it!

Its been a fun ride building these amps and I am very happy how everything turned out. I can see myself sticking with this setup for quite a long time and feel that I would be hard pressed to find something better without shelling out the price of a new car to beat it.

If anyone is on the fence about building one of these amps I can say now that I don't think you will be disappointed and all the Hype is well deserved.

Here's a few glamour shots of the final state:

Hello,

Thanks  for the input and Interesting your comments on the bass and speaker movement , i have not heard the NCore stuff and my previous experience with class-d its at the frequency extremes is where i find them lacking , low bass and high frequency.

Glad you are happy and nice setup ....

[barrows]

Here is my stereo nCore build.  Furutech rhodium IEC jack, Cardas rhodium XLRs, Cardas rhodium over copper binding posts, Cardas 11.5 gauge litz wire for speaker output-direct soldered to the boards, Cardas 15.5 gauge litz wire for AC power-direct soldered to the boards, Hi Fi Tuning Supreme fuses.





The amp now sounds great, I have some additional RF damping on the top cover, over the output area.  Break in was really long for me, with the amp gaining in body over time.  This was not a case of me getting used to it, as I was occasionally making comparisons versus my Pass X150.5.  Great amp all around, but not a good match for a lean system...

[PeteG]

Barrows, very nice. Clean and neat.

[a.wayne]

+10 ,  Neat and clean layout Barrows, congrats ......................... 

[EuroDriver]

How difficult was it to remove the speaker terminals and solder direct to the board  ?

Have you had a chance to AB test the HiFi Tuning fuses with the OEM fuses ?

Have you considered adding a separating wall divider between the SMPS and the NCores

A really nice job !  Congrats !

[mjock3]

Nice looking amp Barrows.

Wondering what the blue box is that is under the power lines?

[barrows]

I did some very crude testing for RF emissions of the nCore modules and SMPS 600s during playback with them just sitting on an amp stand.  This allowed me to get the best ideas for where, and in what direction the airborne noise is worst, and I used this information to inform my layout in the chassis.  I found that by having a full size chassis I was able to get enough physical spacing between the modules to not be concerned about interference.  Note also that to make an effective shield for RF really requires aluminum at least a 1/2" thick, so distance really becomes the more practical method.
I would not recommend removing the speaker terminals for anyone who is not confident in their ablities, but it is not hard with a good temperature controlled iron, a solder sucker, and some patience.  You do have to remove the heatsink to do it properly, and the board is tight there, you really need to be careful not to heat things up too much, as it would be possible to damage the board and adjacent components.  I did it because the speaker terminals are brass, and the screws are steel, and I would rather not have those less conductive materials in the signal path.
The blue box is filled with some RF damping compound (secret formula, got to have some mysery right!), and no, I did not A/B the Supreme Fuses vs the OE ones, but they do have substantially less measured R than the stock ones.  The Supreme Fuses have proven to be good for me previously, so I just went ahead and added them.

[Speedskater]

.........
  Note also that to make an effective shield for RF really requires aluminum at least a 1/2" thick, so distance really becomes the more practical method.
..........

That's the thickness needed for power line frequency magnetic fields.  For Radio Frequency fields, only a foil thickness is needed.

[barrows]

Speedskater: I am curious where you got this idea?  Try putting some Al foil around a radio and turn it on, guess what, you still receive stations…  Or try the following very simple test:  take a SMPS 600, and listen for airborne RF with small handheld radio (tuned low in the AM band where there are no stations) with earphones.  Once you get an idea where the field is strongest, and at what distance, then take your piece of Al foil and see how much effect it has on the level of noise picked up by the radio.

[HighRez]

Nice and clean looking Barrows.

Would it be possible to show some close up shots of your hard wired connections? I am curious especially with the IEC input connection to the SMPS600.

Thanks

[HighRez]

Hello,

Thanks  for the input and Interesting your comments on the bass and speaker movement , i have not heard the NCore stuff and my previous experience with class-d its at the frequency extremes is where i find them lacking , low bass and high frequency.

Glad you are happy and nice setup ....

Thanks

[*Scotty*]

Regardless of thickness it helps if the RF has somewhere to go,(ie,ground).
The only other Effective RF shield is a Faraday cage, which doesn't have to be grounded.
Scotty

[barrows]

highres:  I am not up for opening the amp and taking lots more photos.  The connections are simple; I de-soldered the two pin plug, this exposes the  through plated holes in the PCB.  Then I cleaned these out of excess solder (sucker and solder wick) and then cleaned the area with flux cleaner.  Then, I soldered the (pre-tinned via solder pot) ends of the stripped Cardas wire into the PCB holes.  Finally I slid some short pieces of heatshrink over the opposite ends of the wire flush with the top surface of the pcb, and hit it with the iron to shrink it up, this gives a finished appearance at the top of the board and insulates.  I like the Cardas wire, but tinning it is a bit of a pain, nice thing is that the copper is totally protected from oxidation, and the Teflon insulation can take a lot of heat without melting.

[HighRez]

       .......

It's all good, I understand

[Rclark]

Hirez did you still need pictures up close? I can snap some for you if need be. Mine were textbook built by JTWrace, who I'm sure used a robot or something.

[HighRez]

If its not much trouble I would appreciate seeing any pictures you may have... 

My curiosity is regarding what people are using for a dielectric/insulator between the hard wired wires where the posts previously lived.  Looks like there is a potential for Arching if not insulated in some way.

Thanks

[jtwrace]

Hirez did you still need pictures up close? I can snap some for you if need be. Mine were textbook built by JTWrace, who I'm sure used a robot or something.

I didn't solder direct to the board though. The pics are here http://www.audiocircle.com/index.php?topic=106187.msg1104426#msg1104426

[Speedskater]

Speedskater: I am curious where you got this idea?  Try putting some Al foil around a radio and turn it on, guess what, you still receive stations…  Or try the following very simple test:  take a SMPS 600, and listen for airborne RF with small handheld radio (tuned low in the AM band where there are no stations) with earphones.  Once you get an idea where the field is strongest, and at what distance, then take your piece of Al foil and see how much effect it has on the level of noise picked up by the radio.

From the Henry W. Ott book 'Electromagnetic Compatibility Engineering', chapter 6 has 60 pages on shielding.

http://www.hottconsultants.com/EMCE_book_files/emce_book.html

[James Romeyn]

I'm sure it's well know, but just for the record universal industry standard is no OEM service available for any component hard soldered where OEM terminal was screw or quick-disconnect. 

Does Hypex publish Ncore tech/repair service data?