[barrows]

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

As mentioned the wires are heatshrinked over the teflon right up flush to the surface of the board.  I would not worry about arcing though, on the underside of the board the pins of the AC header are totally exposed in stock condition.

Absolutely James, direct soldering like this will likely void warranty protection and serviceability.  If I was seeking service from Hypex on any of these modules, I would first return them to stock condition.

[rogerdn]

Dave at P.I. Audio graciously built this beauty for me, which sounds just stunning, liquid, dead quiet, with great dynamics and soundstage.  I have posted below his build notes he sent to me.  Dave said he would be glad to answer questions.....but....I got the 'last one'....he did it as a favor.

'I think that this particular amp is one that would satiusfy even a dedicated tube guy like me.  With the cryo, parts selection and all of the shielding that I did I think that made a pretty significant impact on that amp.

You can see the RFI/EMI shield that I built separating the power supplies from the amps.  It is made from mu-metal and copper sheet and foil over a masonite core.  The shield is electrically isolated from the chassis and is connected only to the ground pin on the IEC.

You can also see the copper foil shielding around the power supply leads and the ferrite beads on the power leads.  The rear panel has the Furutech IEC inlet and a better power switch.  I used a DPST switch and used both sides for power. The switch wire is enclosed in a shielded cable that runs almost completely in the power supply section of the amp as defined by the mumetal/copperfoil divider that I built for the amp. 

There is also a picture of thedamping pad on the bottom of the top coverplate.  It is covered with ERS cloth for RFI mitigation.  I didn't put any ERS under the power supplies so as not to interfere with any thermal dissipation through the bottom panel and I believe that one side is enough.
 
The amp plates have heatsink compound in the gap.  There is adequate interior space for circulation for the
power supplies with a small gap above and below the shield.'

[JerryM]

Very nice!!!   

[mjock3]

Very sharp, you have some nice ideas that were implemented. 

[rogerdn]

Very sharp, you have some nice ideas that were implemented. 

Thks but they were all Dave's.

[poseidonsvoice]

Wow! Looks great and nice ideas. I used a nice amount of shielding in a recent balanced AVC preamp build, and I might want to add some ERS to my own NCore build. Have to be careful in my situation since there is little space between the top cover and power supply heat sink.

Great build Dave! And congrats Roger!

Best,
Anand.

[Julf]

Beautiful - and perfect example of the adage "if it is worth doing, it is worth overdoing"

[rogerdn]

Beautiful - and perfect example of the adage "if it is worth doing, it is worth overdoing"

 

[rogerdn]

Wow! Looks great and nice ideas. I used a nice amount of shielding in a recent balanced AVC preamp build, and I might want to add some ERS to my own NCore build. Have to be careful in my situation since there is little space between the top cover and power supply heat sink.

Great build Dave! And congrats Roger!

Best,
Anand.

Anand, I should have clarified the ERS Dave did on the cover, the picture is an earlier one (and I did not retake ) as he removed some of it after listening more, here is his comment,

'One of the things that I did was reduce the size of the ERS cloth on the cover from the first time I listened to the amp.  The soundstage opened up quite a bit with that.  ERS is a funny material... very quirky in the way it behaves and interacts with electronics.  I removed it over the amp section of the chassis and left it over the power supply side'.

So less is more in this case apparently and you should experiment with the placement.

[James Romeyn]

Very sweet dual mono Ncore!  One of the more interesting designs I've seen.  Good on Dave, good for you! 

[poseidonsvoice]

Anand, I should have clarified the ERS Dave did on the cover, the picture is an earlier one (and I did not retake ) as he removed some of it after listening more, here is his comment,

'One of the things that I did was reduce the size of the ERS cloth on the cover from the first time I listened to the amp.  The soundstage opened up quite a bit with that.  ERS is a funny material... very quirky in the way it behaves and interacts with electronics.  I removed it over the amp section of the chassis and left it over the power supply side'.

So less is more in this case apparently and you should experiment with the placement.

I have heard that before, that TOO much ERS can dull the sound...

Best,
Anand.

[HighRez]

Very nice component layout and shielding choices.

[Julf]

I have heard that before, that TOO much ERS can dull the sound...

How would that work?

[poseidonsvoice]

How would that work?

Gee, I wish I knew! No objective measurements that I have seen/read to support that claim however, just anectodal reports on the net...

However, in some analog circuits, the presence of EMI/RFI was tuned into the frequency response of the device. ers can effect of the amplitude of the high frequency and/or the low frequency extremes resulting in a less than desirable balance.

Best,
Anand.

[Julf]

Gee, I wish I knew! No objective measurements that I have seen/read to support that claim however, just anectodal reports on the net...

Ah, OK. Even if the ers stuff affected the circuits, it is rather unlikely that the effect would be as simple and straightforward as to "dull" the sound.

[poseidonsvoice]

Ah, OK. Even if the ers stuff affected the circuits, it is rather unlikely that the effect would be as simple and straightforward as to "dull" the sound.

From the same link above:

Crossovers - Covering the top bottom and sides, as well as wrapping the internal wires. This method needs to be "tuned" to each individual system. You will know when you've added too much ers, when the highs start rolling off, or midrange detail starts disappearing. Be prepared to spend some time on this.

Best,
Anand.

[Julf]

From the same link above:

Crossovers - Covering the top bottom and sides, as well as wrapping the internal wires. This method needs to be "tuned" to each individual system. You will know when you've added too much ers, when the highs start rolling off, or midrange detail starts disappearing. Be prepared to spend some time on this.

It does sound a bit too voodoo for my taste, but at least with a simple, analog crossover you might be able to show loss of upper frequencies if you add a lot of capacitive loading to the circuits. Slightly different story for active systems with feedback and amplification.

[poseidonsvoice]

It does sound a bit too voodoo for my taste, but at least with a simple, analog crossover you might be able to show loss of upper frequencies if you add a lot of capacitive loading to the circuits. Slightly different story for active systems with feedback and amplification.

It's not that it's a bit too voodoo, it is voodoo, until proven with measurements! So although I do have some ERS around myself to experiment with, I have absolutely no backup to know how it affects frequencies from 20kHz on down...which is probably why I haven't used it in years, cause I'm not sure if it works. I'm sure Dave of PiAudio has experimented with it tons and may know what measurements will point us to judiciously implement ERS. I can't make a direct connection between attenuation in the gigahertz/megahertz frequencies and how that affects human perception of stereophonic playback in a room!

Perhaps I need to read more! I admit my knowledge of RFI, EMI, and power line frequency shielding sucks big time 

Sorry for off topic rant...

Best,

Anand.

[rogerdn]

On the parts that were cryoed Dave says,

..... the power modules, the power supplies and all of the wiring.  My cryo tank is too small for a whole amp.
 

[jtwrace]

It's not that it's a bit too voodoo, it is voodoo, until proven with measurements!
Best,

Anand.

Yep.  The only thing I've ever done is put my cell phone on it and tried to call it.  It doesn't work whatsoever.  Take it off, it rings.  So it does block that FWIW.