Hypex Ncore

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Not going to resonate if it is twisted or braided. Oxidation isn't a problem with silver wire or lacquered copper....

Twisting or braiding is irrelevant if the wire isn't constrained within the tube- unless the braid is so tight as to pull the conductors tight against the insides of the tubes. And as the assembly is moved, they'll naturally create space over time.

Back before I knew how to design speakers, I spent a lot of time with the minutia of audio cables. Now, in perspective, it seems kind of silly. Pretty minor effects compared to speakers and circuits. But one effect that could be significant were mechanical resonances and associated microphonics in audio cables.

I wound up using a wrapped conductor constrained with a matrix of teflon tubes to achieve good damping but also significant spacing and low dielectric absorbtion.

But there's not a lot to fuss about in a nice quality balanced input wire, unlesss you add flavor by getting overfancy in the wrong ways. With single-ended, the cable starts to matter more.

A very solid recipe for balanced is to use a twisted pair of your preferred conductor, with a dissimilar (different awg) ground conductor run parallel to the twisted pair, all wrapped with teflon tape (get the 1.5" mil-spec stuff from McMaster Carr), spray this assembly with some anti-static carpet fluid and slide into an overall teflon tube. Insert smaller tubes into the gap in the assembly at either end as far as you can, to restrain the conductor assembly within the tube, and make the ends more dense and durable. Then use an overall shield and terminate properly, generally "telescoping", or grounded at the source end, is a good choice.

But it's a lot of effort and cost for a very small gain, in a short internal run of balanced cable.

Kimber "varistrand" copper makes a great ground wire for this type of assembly.

And now that I've given that all away..... :)
 
If the wire wasn't constrained within the tube, it would fall out. Putting a 28 gauge wire in a 24 gauge piece of eptfe is no easy chore. Braiding or twisting will result in the wire touching the inside of the insulation at multiple points, and will securely hold it. I wasn't talking about a 28 gauge wire in a 12 awg tube....
 

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The cases that I am going to use for my Ncores will allow me to mount the PS and the amp modules on opposite sides of a vertical 2mm aluminum sheet. I will also mount them as far apart in the vertical plane as the power connector lead will allow. So I'm looking to minimize the magnetic field interaction as much as possible in this way. Any comments from those who know about these things?
 
The cases that I am going to use for my Ncores will allow me to mount the PS and the amp modules on opposite sides of a vertical 2mm aluminum sheet. I will also mount them as far apart in the vertical plane as the power connector lead will allow. So I'm looking to minimize the magnetic field interaction as much as possible in this way. Any comments from those who know about these things?
keep the cables as sensibly short as you can
Keep psu harness and speaker cables as sensibly away from each other as you can
Twist psu and speaker cables as much as you can

Otherwise don't worry
:)
 
Possible grounding issue?

Wondering if anyone has, any suggestions here:

I have 3 NC400 and 3 SMPS600 built with triggers in 3 monoblock units.

Source is a Denon AVR-3312. So input is RCA to XLR on the NC400. I was going to wire the XLR cable as suggested in the manual, with the sleeve of the RCA connected to pins 1 and 3 of the XLR. But I note the manual says assuming that the RCA sleeve on the source is bonded to the chasis. The Denon AVR power cord is a 2-pin connection only, so I think the RCA sleeve may not be connected to the Denon chasis.

With the above XLR cable, my home circuit breaker trips. When I disconnect the XLR cable, amp stays on but I feel a tingling at the connectors behind the amp.

Thinking that the Denon RCA might not be connected to its chasis and so causing the trip, I floated the XLR cable pin 1 (ie, disconnected the interconnect wire that was connected to pin 1). The trigger ground (from the 3.5mm input) and J9:4 are grounded to chasis. Also decided to ground the IEC to chasis.

Why is it that this trips my home circuit breaker (only power cord connected, XLR cable not connected)? IEC ground cannot be connect to chasis?

Funny thing is in another house, this doesn't trip the circuit breaker.

Thanks for reading and advising.
 
European or US 3-phase? 3-wire or 4-wire? Any idea how your (2-phase) power outlets are wired into the 3-phase feeds?

Not US. 230V. I think its 4 wire. Into the house, its split up in 3 separate circuits, so it is unbalanced. Tested and found the potential difference between the ground and neutral is about 2 to 4V.

Did some more poking around, might have found the problem. Have a 2-colour LED connected to show standby and active mode. When the circuit for the red standby light is deactivated, the amp doesn't trip the circuit board anymore. Will troubleshoot this now. Thinking of putting in a small transformer to isolate this standby/active LED indicator circuit from the main circuit.
 
Wondering if anyone has, any suggestions here:

I have 3 NC400 and 3 SMPS600 built with triggers in 3 monoblock units.

<snip>

The trigger ground (from the 3.5mm input) and J9:4 are grounded to chasis. Also decided to ground the IEC to chasis.

<snip>

Not clear from this what your trigger circuit is and how it's connected

As you seem to have discovered in your later post
- disconnect all additional circuitry other than the ncore and smps and then see what happens
- debug the ncore and smps wiring on their own
- then try examining any additional circuitry you're using
 
Great Sound, but running hot

I finished building my Ncore amps yesterday night and my first listening impressions are very good. Tremendous clarity, but without digital edginess. Many Ncore owners reported about the amazing bass control. Actually it seemed to me that the bass was going down much deeper than with my Musical Fidelity X-150 and it was actually much more refined and yes, controlled, too. But what I enjoy most is the amount of nuances the amps give to natural instruments. There seems to be more color in the decays and more personality to the individual instruments.
The only thing that worries me is the heat these tiny little amps pick up. They get much hotter than I actually expected, although I listen at really moderate levels. I left them turned on during the day presuming that with the dedicated power supply they'd automatically turn to standby mode. Maybe that didn't happen and that's the problem? Any advice on the heat issue would be welcome.
For the rest: whoever wants to come and listen to these amps in or around Berlin, Germany, is welcome to do so
 
Sonnenwender,

Depending on how large your chassis is, heat really shouldn't be a significant problem. If you look at my build above (post#4911), you will see that I designed in vent holes on the top chassis. My entire chassis is very small about 215mm x 70mm x 228mm. The chassis only gets warm even when playing for several hours and I have the unit on 'standby' all the time except for listening. I just engage or disengage the AmpOn wire from ground to switch from 'standby' to play. I do know that the unit doesn't 'automatically' switch from standby mode. I have to manually switch it!

All the best, and Enjoy!

Anand.
 
Sonnenwender,

Depending on how large your chassis is, heat really shouldn't be a significant problem. If you look at my build above (post#4911), you will see that I designed in vent holes on the top chassis. My entire chassis is very small about 215mm x 70mm x 228mm. The chassis only gets warm even when playing for several hours and I have the unit on 'standby' all the time except for listening. I just engage or disengage the AmpOn wire from ground to switch from 'standby' to play. I do know that the unit doesn't 'automatically' switch from standby mode. I have to manually switch it!

All the best, and Enjoy!

Anand.

Dear Anand, which one exactly is the AmpOn wire? I guess I will have to incorporate a switch to disconnect the amp from power when I am away. Might also be a problem of the cases. I bought the dedicated cases from Siliconray with the engraved Ncore logo. They look very nice, but they are completely closed without venting holes. Anybody else out there who used those cases and has heat issues?
 
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