[poseidonsvoice]

Anand.

[Don_S]

bluse2,

Very nicely done.  Did you build the CD transport/player as well?

Welcome to Audio Circle.

[bluse2]

bluse2,

Very nicely done.  Did you build the CD transport/player as well?

Welcome to Audio Circle.

Yes I built the CD transport using CD-PRO2 module as well.

[jmbulg]

Very nice cases, where did you get them?

[SlushPuppy]

Nice work bluse2!

Those cases remind me of the Doge 8 Clarity Preamplifier, which I'm a big fan of.


Slush

[James Romeyn]

Yes, that is toe-headed Ron Howard, AKA "Opie Taylor".  Disclaimer: not my DVD.   

Only one built and functioning so far (installed in center channel of Trinaural Music system).  I listened to only the center channel.  Trinaural center channel output does not have the phase anomalies of summed mono L+R signal.  So far so good. 

Certified scale: 5lbs 1.9oz...amp board and ps board alone 1lb 3.9oz. 

I'll post system details and more feedback after I finish all three amps/power cables/IC.  First impressions after only a few hours of use.  It's quite a bit different from the AKSA Naksa 100.  Main speakers are high-pass crossed 2nd Order in-phase @ 80 Hz (Trinaural Processor...5-piece sub described HERE).  Each channel of my speaker system is two 8 Ohm stand mount monitors in THIS unique array.  Each channel can present either of the following two loads to the amp:

2.7 Ohm minimum @ 200 Hz, 4 Ohms flat above 600 Hz (parallel) OR
10.6 Ohm minimum @ 200 Hz, 16 Ohms flat above 600 Hz (series)

I presume the following is correct: Ncore maximum power is about 500Wrms into the former load, about 100Wrms into the latter load, with concomitant lower distortion and much lower current demands.  Into the latter load, Ncore power limits at the higher 16 Ohm impedance, but has higher power potential (about 160W) @ the 200 Hz minimum, if the music program demands such only in that range. 

Anyway, I listened to Telarc's well recorded Glinka: Ruslan And Ludmila Overture.  First several times @ 16 Ohms/series, then 4 Ohms/parallel.  As expected, there appeared to be a 6 dB gain difference and thank goodness my preamp has dB steps. 

The difference was similar to every SS amp on which I performed this test.  16 Ohms sounded better by significant margin.  With lesser amps the sound quality outweighed the power deficit.  In this case, much better sound but with apparently unlimited SPL, yes, even @ 16 Ohms (each channel of my system, comprising two speakers, about 88 dB actual sensitivity). 

4 Ohm (2.7 Ohm minimum) sound quality was, well, frankly, not very special.  It was OK, nothing awful, just not inviting.  I'm as surprised as anyone else.  Switching to 16 Ohms (10.6 minimum) was a revelation.  My best analogy is an extremely linear and transparent 400W tube amp.  From the mid bass up through the lower mid range "sound density" was like a great, smooth horn system, but with superb transparency.  IOW, it was thick as soup and transparent at the same time.  Detail and layering was phenomenal.  Differences between the string instrument ranges was superb.  Ncore excelled in tonal variety, the same area in which Tyson said it was inferior to his lovely 70W tube mono blocks.  Go figure.

So far I like it.       

The Trinaural allows perfect integration (yes, I mean perfect, absolutely no negative impact with either format) of music/HT if/when a perforated screen/front projector is employed.  I later put on Cream Live At Albert Hall.  Even with only one Ncore amp (L/R channel power is circa 2003 YBA Audio Refinement with minor mods) I'm here to tell you this 100W Ncore/speaker interface might be mistaken for 400W.  There is so much more presence in the mid bass range that I'm quite sure I'll need to re-adjust the sub xo.  Oh well.

My best/closest comparison, with this admittedly very limited experience, is to an Ampzilla 2000 mono block Series II (200/400/800W @ 8/4/2 Ohms).  IMO the Ampzilla would seem to handle lower impedance much better.  You better get something for 65 lbs and almost $4k per channel!  This is interesting, because both designers are hard core fanatics (maybe among the most fanatical) for low distortion figures.  Several years ago at CES, Ampzilla and Trinaural designer James Bongiorno asked a Meridian engineer about their technical equipment.  James chuckled, saying he stopped using that gear a long time prior.  I'd love to hear a conversation between Bongiorno and Putzeys.           

[jtwrace]

Nice.

Now you just need some black SHCS for that black front panel.

[James Romeyn]

Jason,
Will you please stop posting that hi-res close-up of your lovely faceplate, shaming all the rest of us mere "plebs?" 

[mr_bill]

Well I have 4 ohm speakers - are these not super amps for lower imp speakers?
That wouldn't be good.

[James Romeyn]

Well I have 4 ohm speakers - are these not super amps for lower imp speakers?
That wouldn't be good.

Bill,
At least a half dozen major variables invalidate any summary prediction of amp/speaker interface.  Look closely at my low impedance spec of about 2.8 Ohms @ 200 Ohms (when my two monitors are in parallel...in series it's only 10.6 Ohms).  I don't know my phase angle, but suspect it's moderate.

What's the speaker's minimum impedance?  Over what range?  Sensitivity?  Room volume?  (mine's about 3200cf)  Peaks 108 dB here (for not-too-long periods). 

Ncore appears to have considerable power reserve whether 16 or 4 Ohms, but I much prefer the musical presentation in 16 Ohms.  The top front-firing monitor alone is an 8 Ohm load (5.3 Ohms minimum).  I will listen to that later, full range without the subs (-3 dB mid-40 Hz range). 

Finished 2nd amp today.  One amp to go, two power cords, and two IC.     

[kevinh]

James I really like the board layout and the wiring in the chassis. Nice work!

[ajst2duk]

James that's a great write-up. I like the cases - even the jaunty cock-eyed angle of the signal sockets !!! I'm interested in that a few people that have either trialled the Ncores in the US tour, or have built them, also have amps designed by Hugh Dean, ie; life force, Naksa, in my case Fetzilla (with Swordfishy designing, Hugh arranging PCB's). They re great sounding amps, and I am using both my Ncore and Fetzilla along with Plinius. I really like the Ncores - into 8ohm 86db standmount Lenehan speakers. They are stunning, I think the Naksa 100 (which I had for a while), and the Fetzilla, are slightly warmer sounding amps, but very musical. The Ncores are another prospect altogether, they really showed up my digital source (SB Touch via Synchro-mesh into eiher Audio GD REF 5.2 or TeddyDac) as wanting, however with an Ortofon 2M Black via PS Audio GCPH phono stage, it was totally glorius sound at any volume. The digital sounds better behind either the Fetzilla or Plinius. Ruthlessly revealing is how I would characterise them.
Very glad I've had the opportunity with some time off to experience these amps, truly a marvel.
AJ

[drmike]

hey james,
did you use the supplied iec, what xlr? thanks for the photos.
drmike

[drubin]

James, I'll echo the compliments on your layout. Can you describe the grounding arrangement you've implemented?  Looks like you have three things connected to one of the power supply offset posts, is that right?

[audio-heaven]

James that's a great write-up. I like the cases - even the jaunty cock-eyed angle of the signal sockets !!! I'm interested in that a few people that have either trialled the Ncores in the US tour, or have built them, also have amps designed by Hugh Dean, ie; life force, Naksa, in my case Fetzilla (with Swordfishy designing, Hugh arranging PCB's). They re great sounding amps, and I am using both my Ncore and Fetzilla along with Plinius. I really like the Ncores - into 8ohm 86db standmount Lenehan speakers. They are stunning, I think the Naksa 100 (which I had for a while), and the Fetzilla, are slightly warmer sounding amps, but very musical. The Ncores are another prospect altogether, they really showed up my digital source (SB Touch via Synchro-mesh into eiher Audio GD REF 5.2 or TeddyDac) as wanting, however with an Ortofon 2M Black via PS Audio GCPH phono stage, it was totally glorius sound at any volume. The digital sounds better behind either the Fetzilla or Plinius. Ruthlessly revealing is how I would characterise them.
Very glad I've had the opportunity with some time off to experience these amps, truly a marvel.
AJ

Very nice indeed - just one little comment tho - Bruno says the speaker wires from the Ncore should face the other way (away from the board) or it will introduce some unwanted noise.

[James Romeyn]

hey james,
did you use the supplied iec, what xlr? thanks for the photos.
drmike

That was a nice/unexpected surprise finding the supplied IEC.  In direct comparison the supplied IEC had a bit more tension/torque (estimate 20-30%) vs. the PX piece, so of course I used the supplied IEC.

XLR female chassis jack: Neutrik NC3FP-1.  I really love these, they are  great.

Notes about the chassis: For $93 total delivered to my door (IIRC), these exceed expectations by decent margin.  Fit and finish quite good, I've seen better stencil, but its adequate.  Screws seem hardened and good finish, black not coming off during install/remove/install several times already.  I've seen much cheaper screws on production pieces.  Faceplate is nice and heavy (check the weight above, this ain't a lightweight chassis).  What a surprise and delight to find they threaded the fastener holes for the IEC and XLR, eliminating the need for a nut.  They also supplied all necessary screws for complete assembly of even the IEC and XLR.  I used a Dremel to remove black finish from the bottom of the chassis for the screw fastening the earth terminal of the PS (I added a small ring terminal at the earth terminal screw on the PS for common earth: IEC, XLR, and Nampon.) 

At first I was disappointed about the XLR turned 20 degrees from vertical, but best I can tell this tilt orients the solder well vertical.  We all know the misery of soldering a solder well that's not vertical.

If you use the binding posts I specified, don't fill up the solder well with wire.  The well is absolutely huge; maybe AWG10 would fit.  On this first amp, on the first post, I doubled/bent over AWG14 in the well, which requires so much heat to melt solder that I slightly deformed the nylon insulator.  I soldered with the solder well vertical and the nut slightly loose (the post wire hole was vertical).  After the solder dried I turned the post hole horizontal and torqued the nut.  I'd say the maximum tinned AWG size for the Ncore gold speaker terminal is AWG14.  Personally, I'd not exceed AWG14 speaker wire.       

I really love the Mogami wire Bruno supplied, it's great quality and the insulation withstands good heat w/o deformation.  But...(sorry to even mention this) my favorite commercial wire for this application is still the smaller AWG Canare Star Quad, which is braided shield coaxial 4-conductor (two white, two blue).  The user simply parallels the same color conductors.  Compared to two conductors, four conductor wire gauge is smaller (higher numerically), with tighter clearance between the wires including those of opposite polarity (dramatically and exponentially, IMO).  The tighter the clearance the greater the noise cancelling effect (explaining why Bruno recommends a tight wire twist).  The drawback (no free lunch, again) is cost and longer/more difficult assembly (four smaller wires vs. two larger).  I realize the length is small in this amp.

I'm a bit surprised at idle temperature, but it's not serious.  My ambiance array (see link above) has a second monitor on its back on the floor firing up (inverted polarity vs. front).  The ambiance monitor uses floor space behind the speaker stand, requiring my Ncore to site vertical.  I first sited it face down, but this flows PS heat (hottest component is PS caps) upward directly over the amp module.  I'll fix this by siting the amps side-panel down.
 
I'd probably prefer about 10mm less clearance between the posts to minimize post-twist length.  I think these are great posts, and incredible value.   


       

[James Romeyn]

James, I'll echo the compliments on your layout. Can you describe the grounding arrangement you've implemented?  Looks like you have three things connected to one of the power supply offset posts, is that right?

Yes, as noted above, I removed finish under the chassis at the screw fastening the PS earth terminal.  Above, at the earth screw on the PS board, I added a ring terminal as common earth for IEC, XLR, and Nampon.  This was the most convenient method because the chassis holes for the IEC and XLR are threaded, requiring no nut.  If a nut was required I would have been tempted to add a ring terminal on one of those fasteners as did others.  This chassis' thread and screws seem well above average in durability.     

[James Romeyn]

Very nice indeed - just one little comment tho - Bruno says the speaker wires from the Ncore should face the other way (away from the board) or it will introduce some unwanted noise.

So, looking at my amp, my speaker wires head East, right?  If I understand correctly, "away from the board" in my case would mean the wires leaving the amp should turn North a bit, then turn toward the posts.  Correct?  In your image the wires pass longer over the board, heading South.  If convenient, please note the page to refer to in the instructions.  Very sorry I missed this. 

I have four more amps to build (three for a friend) so this is helpful. 

[Don_S]

James,

I noticed the lid does not fit flush on one side. It shows in both pictures from the front and rear. The ex-carpenter in me wants to take a hammer and block of wood and fix it. 

What's the story?  Other than that very nice casework and amp build.

[James Romeyn]

James,

I noticed the lid does not fit flush on one side. It shows in both pictures from the front and rear. The ex-carpenter in me wants to take a hammer and block of wood and fix it. 

What's the story?  Other than that very nice casework and amp build.

I hit it full swing with an old pick axe I stole from the SFFD before I retired...Sorry I didn't notice this before taking the image.  The panels screw together, resulting in about .1mm too little clearance for the last piece, being the top.  Snapped smartly together with just a little bit of tension.