Hypex NCore question and answers

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Atlplasma

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Re: Hypex NCore question and answers
« Reply #420 on: 14 Nov 2012, 05:28 pm »
....need to get a few more bits before I start to build the encores. Could someone tell me what type/size crimp I need to connect the     
(TE Connectivity 15CUE1) IEC inlet, and also what are those plastic covers called that slide over the crimp. If someone could point me to a website to order in the UK or just to show what I need to order would be a great help. Thanks.

I used Tyco 22-18 crimp on connectors. The gold plated connectors are probably what you should look for. In the US, they are commonly sold at auto supply stores. The insulator is integrated with the connector, so you don't need anything else.

dan92075

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Re: Hypex NCore question and answers
« Reply #421 on: 15 Nov 2012, 01:51 am »
Is the basic idea of the Tyco that you stick in the power cable on one side, crimp using a crimping tool,  and then plug the other side into the IEC socket?

Do you crimp on the IEC socket too, or just plug in?

Sorry if these are novice questions. . .

acousticimagery

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Re: Hypex NCore question and answers
« Reply #422 on: 15 Nov 2012, 11:46 am »
@DaveX & @dan92075

The connectors you need used to be called 'Lucas or Lucar' spade connectors in the UK and Hypex supply the same thing called 'Fastons'.

Hypex only do the 6.3mm wide Fastons and what you need is the smaller 4.8mm wide ones for the rear connections to the IEC input sockets.

Here's a good supplier in the UK for both sizes.... http://www.jprelec.co.uk/store.asp/c=427/Fully-Insulated-Fem.-Push-on-Receptacles

You crimp the mains cables onto the 'spades' with a crimp tool. The one I use and it's good value (11 euros +VAT), is from Hypex....  https://www.hypexshop.com/ and is under 'tooling'.

@dan92075   Then you just push the spade recepticle firmly onto the appropriate spade terminal on the rear of the IEC socket. They're designed to 'bite' onto the spade so you must push hard and no need to crimp that bit.

Hope that helps and good luck with the builds and who knows one day you may be able to graduate to a 'full on' pair of NC1200 based amps (lottery permitting !!)

Cheers

John

Atlplasma

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Re: Hypex NCore question and answers
« Reply #423 on: 15 Nov 2012, 01:24 pm »
Is the basic idea of the Tyco that you stick in the power cable on one side, crimp using a crimping tool,  and then plug the other side into the IEC socket?

Do you crimp on the IEC socket too, or just plug in?

Sorry if these are novice questions. . .

acousticimagery has answered your question, but let me add that Youtube is handy for learning how to solve some of these installation challenges. For example, I had no idea how to prep the XLR cable for soldering to the connector but found a short video online that explained the process in a couple of minutes.

jtwrace

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Re: Hypex NCore question and answers
« Reply #424 on: 15 Nov 2012, 01:29 pm »
acousticimagery has answered your question, but let me add that Youtube is handy for learning how to solve some of these installation challenges. For example, I had no idea how to prep the XLR cable for soldering to the connector but found a short video online that explained the process in a couple of minutes.
Since you brought it up, here are the steps on the input wiring and I do tin each wire.


Atlplasma

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Re: Hypex NCore question and answers
« Reply #425 on: 15 Nov 2012, 01:42 pm »
Since you brought it up, here are the steps on the input wiring and I do tin each wire.



Agree that tinning makes it much easier to complete the solder connection without melting the XLR connector. Clip-on heatsinks are also a good idea (at least when I'm soldering).  :icon_lol:

DaveX

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Re: Hypex NCore question and answers
« Reply #426 on: 15 Nov 2012, 06:52 pm »

Hypex only do the 6.3mm wide Fastons and what you need is the smaller 4.8mm wide ones for the rear connections to the IEC input sockets.

John

Another link for 4.8 female crimps and 4.8 PVC covers. The good thing is that you don't have to order in 100 packs, I ordered packs of 25 each.

http://stores.ebay.co.uk/A1-DISTRIBUTORS/Uninsulated-and-PVC-Covers-/_i.html?_fsub=2262592013&_sid=1037930333&_trksid=p4634.c0.m322

seadogs1

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Re: Hypex NCore question and answers
« Reply #427 on: 17 Nov 2012, 03:51 pm »
New question: Has anyone tried a Class A tube preamp with the ncore amps either the 400's or the 1200's? Your impressions. Anyone try a Supratek Cabernet Dual with the ncores?

jtwrace

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Re: Hypex NCore question and answers
« Reply #428 on: 17 Nov 2012, 10:11 pm »
New question: Has anyone tried a Class A tube preamp with the ncore amps either the 400's or the 1200's?
Yes, many of us do.   :thumb:

Quote
Anyone try a Supratek Cabernet Dual with the ncores?
Don't know about this but maybe someone that does will see this.

barrows

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Re: Hypex NCore question and answers
« Reply #429 on: 22 Nov 2012, 09:06 pm »
nC400 wiring: I am well aware of the recommended wiring strategy for nC400 module input wiring (pin 1 direct to chassis, Shield wire direct to chassis, nAmpon to G/chassis), but I am wondering if anyone has tried alternative approaches.
Many audio manufacturers avoid tying the signal ground (pin 1) to the chassis, as they feel the chassis generally has plenty of RFI on it, and hooking up the signal ground to the chassis gives a path for this RFI to easily get into the circuit.  Note, that the ground of the SMPS600 is connected to the chassis through the single metal standoff.
I am wondering if there may be an advantage to connecting pin 1 only to the shield wire, and not to the chassis-also note that most audio interconnects are not wired as shown in Hypex's diagrams: the shield of a high end balanced interconnect is usually only connected at the source end, and a separate discrete wire is used to carry the signal ground.
I am assuming class 2 construction with no AC ground connection (for similar reasons, many feel that connecting AC ground to the chassis just allows for another path for unwanted noise to get into the circuit).

Shaman

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Re: Hypex NCore question and answers
« Reply #430 on: 23 Nov 2012, 12:18 pm »
Many audio manufacturers...

Many audio manufacturers are wrong, in that they treat pin1 as part of the audio circuit while it should exclusively be seen as part of the chassis/shield.
A search with the term "Pin1 problem" will yield plenty of results.
E.g. see Rane Note 110, Note 151, the AES48-2005 standard or Neil Muncy's "Noise Susceptibility in Analog and Digital Signal Processing Systems" seminal paper.

Speedskater

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Re: Hypex NCore question and answers
« Reply #431 on: 23 Nov 2012, 12:54 pm »
"barrows" you have it all upside down. All shields should be connected directly to the chassis, with as short a wire as possible.  You want the noise to stay on the chassis/enclosure, where the chassis acts just like the cable shield. Almost all balanced cable shields are connected at both ends,  only under special conditions could the shield at the receive end be lifted (and in  those special cases use a hybrid connection).

barrows

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Re: Hypex NCore question and answers
« Reply #432 on: 23 Nov 2012, 04:29 pm »
Actually, no, I do not have it "wrong" and neither do many well respected audio manufacturers who may do this differently than the "AES way".  I think if you do a little digging, you would be surprised to find that many audio cables terminate the shield in a balanced cable at only the source end.
I am very aware of the "pin 1 problem" papers, etc...  My point is specifically that there is more than one way to do this, and there is no definitive "right" way, except for the closed minded.
For example, consider Ayre, they float the chassis of their preamps entirely, no pin 1 connection to chassis, and no AC ground connection to chassis.  Now, go to Stereophile.com and read the measurements of the Ayre KX-R preamp, see any "problems" associated with this way of doing things...

Certainly, if one does things by the "AES way" it will work, and especially in the complex enviroment of pro audio, where controlling ground loops can be a very complex issue, it is advisable to follow the "AES way".  But, in home audio, especially with DIY, we have other options available, which may actually improve performance, we can explore those options.  As long as we consider all connected components (including cables, many audiophile cables ae unshielded as well) as a system, and do what we need to to avoid ground loops, we may find better performance through a different wiring scheme.
The point of this question is to ask if anyone has tried this yet, not to get lectured about the "right" way to do it according to the AES.

Shaman

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Re: Hypex NCore question and answers
« Reply #433 on: 24 Nov 2012, 10:39 am »
I think if you do a little digging, you would be surprised to find that many audio cables terminate the shield in a balanced cable at only the source end.

Which, if you do a little more digging, has been found to make some sense only in "non-AES" terminated balanced lines.
If you do it the "AES way", you're better off connecting shields on both ends. I have the links somewhere, I can look them up if you're genuinely interested.
Of course these are all "details" for some cable companies, many of whom have no technical background whatsoever and only "experiment" (with built-to-order cables from proper manufacturers) with the aim of differentiating their products.

Standards become standards for a reason; they do work in a predictable and effective (objectively proven) way.
I didn't mean to "lecture" you; your question genuinely had me thinking you are unaware of the technical research on which the standards were based.
Since, allegedly, you are aware of said work I'm afraid I can't help you. Life is too short and my time is too valuable to go on re-inventing the wheel (that is: even if I had the means to counter all the technical arguments clearly presented by Muncy and his peers who exposed the pin1 problem) or "revolt" against the standards.

Still, if you do have the technical means to do so, please keep us updated with your (objective, preferably) findings.  :wink:
At the very least, it'll be fun to see that even bright, knowledgeable and talented people like Bruno can be unaware of wiring schemes that help get the best out of the state-of-the-art amps they've designed. :green:

barrows

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Re: Hypex NCore question and answers
« Reply #434 on: 24 Nov 2012, 03:29 pm »
Well it is easy for me to be relatively objective in my evaluation.  I can hear the noise floor of the nCore modules with my ear within a 1/2" of my tweeters, so I will be able to objectively say if there is a "problem" or not with the noise level, RF coupling into the circuit is a little bit different though.
I have read most of the papers you are referring to, but I did do a little refresher reading yesterday, and I investigated my preferred pair of balanced cables here.  The cables have the shield terminated at both ends to pin 1.
But, the recommendation of Hypex does not appear to be the exact same as most of the "AES approved" methods: Hypex wants one to terminate pin 1 to chassis, and to then terminate the shield of their input wiring also chassis, at a different point, but close to the XLR (they want to maintain the shield of the input cabling).  But this is not the same as the general recommendation for terminating the signal ground to chassis (the Hypex input cable shield is signal ground as well).  Also, consider a stereo (or multi channel) nCore build, one will now have two (or more) signal ground connections to chassis, at different points, hmmm?  The papers suggest that connecting signal ground to chassis (at a single point), and pin 1 to chassis, will somehow avoid coupling RF running on the shields to the circuitry, but they are still connected through the chassis, and in a stereo amp, one now has some nice paths for potential loops as well when doing it the Hypex way.
Additionally, I have a DAC which has considerable DC from both pin 2 and pin 3 to ground.  There are 3 ways to deal with this: do not connect the signal ground in the source at all to the amp, use output caps, or use an output transformer.  Considering the RF produced by a DAC, I am looking into transformer coupling it with a Jensen or Lundahl.  I also think it might be interesting to experiment with transformer coupling the nCore, as I have some experience with these modules being very sensitive to RF at their inputs.

Shaman

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Re: Hypex NCore question and answers
« Reply #435 on: 25 Nov 2012, 12:07 pm »
There is also an interesting article by Mr. Davenport, over at diyAudio, which addresses Class I/Class II interconnection issues etc.
On a related note, I picked up the habit of integrating safety loop breakers in my projects from Mr. Elliott's website.
I'm also very fond of quality transformers but generally I can't justify the cost unless I plan to use them for BAL/SE conversions as well.

barrows

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Re: Hypex NCore question and answers
« Reply #436 on: 25 Nov 2012, 06:02 pm »
shaman: thanks for the link, lots of good information in Dave's article.  But, he is mostly advocating for classic star grounding schemes, which is quite different from what Hypex recommends.  There is another approach: no AC ground connection, no center tap transformers, full bridge rectification, and grounding the power supply output to signal only through the circuit(s) itself.  Mr. Putzeys has mentioned more than once, that star grounding is entirely ineffective at dealing with high frequency noise.  For wiring the nC400s and SMPS600 Hypex's first recommendation is class 2 construction, with no connection to the AC ground, each SMPS600 referenced to chassis through the one metal leg (be sure to remove annodizing/paint from the chassis at that point), and connecting both pin 1 of the XLR jack, and the shield (ground of the nCore module) to the chassis at different points, as close to the XLR jack as possible.
After much thought, I am going to set up this stereo amp with Hypex's recommended wiring scheme, I will also insure that there is no possible way the AC input wiring can come loose, or short to chassis.  Then I will have some more serious thought and experimenting at hand for figuring the best way to deal with the output wiring scheme of my new DAC build…
Additionally, unless one is using a half inch (or more) thick one piece machined from billet aluminum, or perhaps, a one piece cast copper, chassis, there is no way a multi piece chassis of thin plate is going to shield anything, RF will pass right through the gaps between panels, and the panels themselves.

Rclark

Re: Hypex NCore question and answers
« Reply #437 on: 25 Nov 2012, 06:33 pm »
Well it is easy for me to be relatively objective in my evaluation.  I can hear the noise floor of the nCore modules with my ear within a 1/2" of my tweeters, so I will be able to objectively say if there is a "problem" or not with the noise level, RF coupling into the circuit is a little bit different though.


bull. You're hearing something else causing that, there is no way you can hear the noise floor of these amps, it's 126-130dB down. You're hearing something else.

barrows

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Re: Hypex NCore question and answers
« Reply #438 on: 25 Nov 2012, 06:39 pm »
Sorry, you are wrong.  I live in a rural area, the noise floor in the room on a calm night is very low.  I can hear the noise floor of the amps with my ear within an inch or so of the tweeter.  Simple as that.

cab

Re: Hypex NCore question and answers
« Reply #439 on: 25 Nov 2012, 06:51 pm »
You are the first person to report this. RClark is right, the noise floor is 130db down. I would look for other explanations.