Hypex NCore Build

Brumjam

My return to using passive speakers has left me with an amplifier sized hole in my system. To bridge the gap I have been using Temple Audio monoblocks which are very impressive given their relatively low cost, but they do loose their grip on my speakers as volume increases.

So never having built anything electrical in my life, I've decided to build a pair of monoblocks using Hypex NC400 amplifiers and matching power supplies. The amps, power supplies, binding posts, switches etc have all been despatched today by Hypex hence me starting this thread.

My intention is to post pics as I go through the build and in the process hopefully garner some advice from those who have done this type of build before. First build will be into MDF boxes as a proof of concept then into aluminium enclosures when I'm happy with the overall layout.

A spare set of very old speakers has been purchased just in case I jettison the drivers across my lounge during testing.

James

Alan

Re your last point - very prudent!

You're going to have an interesting time, I think James - thanks for sharing your pics as you progress. Have you done something similar before?

Jim, of this parish, is a Hypex man too, so you'll hopefully get a valuable second opinion as well as keeping the peasants happy with pretty pictures.

Jim

Hi James

Have you gone for the SM supplies?  I've never used them.  I built standard +/- linear supplies with parts from CPC, BHC etc.

400w into 4ohms!  Do you live in a gymnasium? ;-)

After your proof of concept MDF casework I'd suggest some nice hardwood or acrylic.  Aluminium can ring and rattle and all metals act as an arial IMV.

I am very happy with my UCD 180s.  I use them for bass duties only ATM.  They drive my Lowthers very well but not as well as my 807 valve amp.

coops

I will be interested to hear how you get on, I met Bruno Putzeys in Munich, we were discussing primarily his new Mola-Mola amps which use the N-core modules.
Most of it went over my head to be honest, but he is a switched on guy, coincidentally while at Munich I heard Grimm Audio's LS1 loudspeakers, which really sounded good , only later did I discover that Bruno helped design them and they contain the NCore modules.
KR Keith.

Brumjam

Re your last point - very prudent!

You're going to have an interesting time, I think James - thanks for sharing your pics as you progress. Have you done something similar before?

Jim, of this parish, is a Hypex man too, so you'll hopefully get a valuable second opinion as well as keeping the peasants happy with pretty pictures.

Hi Alan. Never done anything like this so I will be going very slowly through the build, even if most of it is plug and play.

Brumjam

Hi James

Have you gone for the SM supplies?  I've never used them.  I built standard +/- linear supplies with parts from CPC, BHC etc.

400w into 4ohms!  Do you live in a gymnasium? ;-)

After your proof of concept MDF casework I'd suggest some nice hardwood or acrylic.  Aluminium can ring and rattle and all metals act as an arial IMV.

I am very happy with my UCD 180s.  I use them for bass duties only ATM.  They drive my Lowthers very well but not as well as my 807 valve amp.

Hi Jim,

Yes, I've gone for the matching SMPS600 SM supplies. Although one supply can power two modules I've gone for one supply per module so that I end up with two boxes.

Thanks for your comments regarding aluminium. I hadn't considered using hardwood which would look nice.

400w should be more than adequate for each channel I reckon ;-). Did you know Hypex also manufacture a version which is three times more powerful? It is not available to the DIY market and has so far only been used by a couple of companies, one of them being Theta and the other being Mola Mola as Keith mentioned.

After the excitement of ordering the stuff from Hypex I had a more down to earth shopping session today in Maplin. Hopefully I now have all the stuff I need to start assembly when the amps arrive. I just need to get a sheet of MDF and some batons now.

James

Brumjam

The nice chaps over at Hypex sent my amps and power supplies last week. Today I've spent four hours making a start on the first monoblock. This was a big learning experience for me not having done any woodwork since college and as you can tell there is room for improvement :-)

Here is a pic of the two amps and power supplies in their original packaging:

In addition to the amps and power supplies I also bought XLR and binding posts from Hypex.  The switched IEC sockets, additional wiring, soldering iron etc all came from Maplin. If you dabble in DIY audio I bet most of the extra stuff you need to build these amps will already be in your home.

As I've already mentioned the boxes I am building are just a proof of concept.  The piece of timber that I purchased was my first mistake.  It really needs to be a lot thinner in order to accommodate the binding posts and mounting screws for the amps and power supplies.  Anyway, here's the sections marked out ready for cutting:

Next photo shows markings for XLR connector, binding posts and IEC socket:

Checking the IEC and XLR connectors fit:

In the above picture of realised there's no hope of the binding posts fitting so I have drilled basic holes to pass the speaker cable through.

Checking where to drill mounting holes for the amp and power supply in the next shot. 

After reading through the instructions 100 times I started to wire it all together:

The wiring is straightforward even for a novice like me.  In the above picture I have connected the power supply cables to the IEC using crimp connectors, but I don't think these are particularly robust so I'll solder them before switching it on.  There's a supplied wiring harness that connects the PSU to the amp - it simply clips into place.  The white wire is speaker cable which goes out to the binding post.  I've started adding earthing wire which will go from one XLR pin, the IEC earth, and the nAmpon trigger into a piece of fuse block, with a wire coming out of the block connected to the ground screw on the PSU (the silver screw, top right of PSU).

So still to do is to solder the input cable wires onto the XLR socket, solder the three wires to the IEC and then clamp the earth wire to the grounding screw - lack of a torx screwdriver meant I couldn't so this today.

@Jim - If you read this I have a question for you if you don't mind:  Would you advise me running the audio output cable shield into the fuse block along with the wire from XLR ground pin and the nAmpon wire?  I've seen some people do this and others not bother.  It seems fiddly to do because I will have to strip the cable right back then twist the shield, then thread it through some hollow cabling etc.

Overall I learnt a great deal from today which I can take forward with my second monoblock before moving on to the finished boxed build.

Any questions, fire away!  I'm not expert so keep 'em simple 

Brumjam

I should have also mentioned that the cable layout in the pics is not how I intend to leave it.....it looks like an homage to Spaghetti Junction at the moment.

Jim

Hi James

Is the sheild connected to anything apart from the body of the XLR plug? I wouldn't bother either way actually, doesn't seem any point.

Re the timber being too thick for the 4mm binding posts: if you have or can get some thin timber, say 3 or 4mm then you can mount the posts to that and mount that to the case going through the holes you've made.

Hope that helps mate.

Brumjam

Thanks Jim. The shield is on the cable running from the amp to the XLR connector (or at least it will be when I connect it). In my last picture it's the thick black cable in the top right hand corner.

Thanks for the tip re the binding posts.

Cheers,

James

Brumjam

Hmmm Hypex show pin 4 connected to ground in their wiring diagram, so I can only think that the braided shield is connected to pin 4 and must therefore be grounded if setup for balanced operation.

Jim

If it's same as on my UCD180 then pin 4 is ground but it's also used for switching the amp board into a kind of stand by mode.  Does the diagram show a switch symbol?

Brumjam

Hi Jim,

Yes, the NC400 has the same arrangement. Pin 4 has a smaller wire which runs separately to the main audio input cable that Hypex term 'nampon'. The amp is muted until this wire is grounded. Although I could connect this to a switch I'm just going to run it to ground on this amp.

I'm going to email Hypex and see whether they advise connecting the audio cable shield to ground as well.

James

Jim

It's not just a mute facility IIRC.  The power draw is also reduced which makes it suitable for leaving on permanently.  I think it draw a paltry 2 watts of leccy in that mode.  But it doesn't power off the transformer or caps etc - which is a good thing.

Brumjam

Thanks Jim. Sounds like I should connect this cable to a switch then on my second amp build. I like the idea of leaving them always on - two less buttons for the family to press when they want to listen to music.

Brumjam

Hypex have confirmed both the 'nampon' cable and the shield on the main audio input cable must both go to ground. I'll post a pic of this in case anyone else is interested in building a similar design.

Initial listening impressions to follow this weekend unless I run into any unforeseen issues/blow my speakers up!

James

uglymusic

Watch it!
[-X :-)

Alan

I'm looking forward to your impressions James, I am reading this thread with great interest.

Jim

Another tip James.  Go to www.cpc.co.uk and buy 2 cheap drive units. Six inch ones will do - you'll spend no more than a tenner.

When you are ready to go plug these in first and play music through for a good half hour - problems don't always present themselves straight away.

Having said that the Hypex modules have short circuit and thermal protection, I've never had a problem.  Though I still do use cheap speakers when making any changes just to be on the safe side.

Brumjam

Tonight I thought I'd try my hand at soldering.  After a few practice attempts soldering pieces of wire together I managed to solder the three wires to the IEC connector.  The XLR was easier to solder because the wire rests in the socket.

The IEC socket I'm using is fused (not strictly necessary because the SMPS has a fuse) and has an integrated switch.  It must be faulty because the first time I turned it on nothing happened.  I disconnected the cable which plugs onto the SMPS and then the cable from the SMPS to amp and reconnected it all up again, making sure every plug was firmly in place.  Second switch on and nothing happened.  This was not a good moment because I have no way of telling whether it was the switch, SMPS or amp.  In addition to the switched IEC sockets I also ordered a couple of Furutech IEC sockets with no fuse or switch. The connections are made via screws instead of solder.  So I duly wired one of these sockets and voila.....glowing lights on the amp!  

An old centre speaker which will be going to landfill shortly was my test speaker.  I connected this up and then connected my Perfectwave DAC via XLR to the amp.  I let it play for 20mins then disconnected the speaker and plugged in my Vivid Audio speaker.  This combo has been playing for 30mins and I've not heard anything untoward - no extraneous noise, pops, crackles or anything that would point to me having wired the amp incorrectly or put wires too close together.

Next step is to build the second amp, ironing out all the mistakes I made with the first one.  I definitely need to make the case slightly larger and use thin MDF.  The main thing now is that I have a reference point for what the wiring should look like.  This in itself will make the second build much quicker.  Total build time for amp number one was eight hours which includes making the box.

Sitting here now feeling rather chuffed with myself  

Alan

So you should feel chuffed - chuffing well done old chap! Proud of you, we are!

You should be done by the end of the jubilee bank holidays...
:!!

Jim

Good stuff James.  How did it sound?

Brumjam

Hi Jim.  The NC400 unit certainly sounds different to my Temple Audio amps.  Hard to make an accurate assessment without having both amps up and running though.  

Really looking forward to building the second amp now.  I wish the weather had held out for a few more days so I could have made the box.  Rain 2 - Hypex 1 at the moment.

Brumjam

Second amp is up and running.  This one took me three hours largely due to silly miscalculations building the box - measure twice, cut once as my Grandad used to tell me.  I'll post pics shortly but my second effort is far tidier.  Using thin MDF and batons at each corner saved me a decent chunk of time.

So how do they sound?  As I eluded to in a previous post they sound different to my current amps.  My initial impression is that they are highly accurate and revealing of the source in a way I've simply never heard before. They are so accurate yet in no way forward or bright in nature.  It's very early days but I'm delighted with my decision to have a go at building my own amps (even if Hypex do most of the work!).

Alan

A promising result, James. Do you think you are looking at something that beats commercial offerings outright, or just performs well in terms of VFM?

Brumjam

That's difficult to say Alan because I've very little experience of amps, compared to the number of DAC's or speakers that have passed through my room.

The NCore amps are a big step up from my current Temple Audio monoblocks, but this isn't surprising given the cost and size differences.

There are a growing number of NCore owners over on Audiocircle who have replaced some fairly exotic amps with these modules, so I have no reason to doubt these amps would stand up well against some fairly expensive commercial designs.

Alan

 There are a growing number of NCore owners over on Audiocircle who have replaced some fairly exotic amps with these modules, so I have no reason to doubt these amps would stand up well against some fairly expensive commercial designs.

That's just what I've been hearing, very interesting.

uglymusic

 There are a growing number of NCore owners over on Audiocircle who have replaced some fairly exotic amps with these modules, so I have no reason to doubt these amps would stand up well against some fairly expensive commercial designs.

That's just what I've been hearing, very interesting.

You've heard Jim's, of course. I think they're pretty good, but I don't think I'd swap my TDSs for them. If only the Hypexes were better...

Alan

I know, but your TDS's are special IMO, leagues ahead of current offerings from the same outfit. I guess that's not all down to power supply size either - the Hypex's certainly turned my head.

uglymusic

Thanks Alan, I do love 'em.

Mine were upgraded component-wise a couple of times as well.

I guess you need to compare your TSS directly with Jim's Hypexes, if you haven't already.

Brumjam

Dave/Alan - I know nothing about NVA amplification but just spent some time reading a review on the TDS monoblocks.  It was written in 1993 and the rrp was £5k - Was this per amp?  :-O  They certainly look the part and seem a departure from photos I have seen of other NVA amps.

I've been listening to my new amps today with my valve pre in and out of the loop.  My preference so far is to connect my DAC direct to the amps.  The immediacy/impact that the Ncore's are capable of is slightly diluted with my preamp in place.  The frequency extremes are rolled off to a degree that I never noticed with my other amps.  This wasn't something that I expected but to be honest if after further listening I remain of the same opinion, then I can cut another box out the chain, free up some cash and make my hi-fi a bit more family friendly.  

Alan

Re that review, was it by a certain Dave Wiley? As in Coyote?

So you can drop another box after all! And after finding your perfect pre as well!! You know, a lightspeed might be just the ticket now...

However, dropping another box & gaining performance is a win win result. Congratulations!

uglymusic

Currently cost £3.5K per channel. Plus a passive pre.

Mine are NVA's prototypes and aren't all shiny/gleamy, alas.

It was possibly my review that you read ;-) Small world...

uglymusic

Re that review, was it by a certain Dave Wiley? As in Coyote?

So you can drop another box after all! And after finding your perfect pre as well!! You know, a lightspeed might be just the ticket now...

However, dropping another box & gaining performance is a win win result. Congratulations!

Thank you Mr Roadrunner... You were so fast you got in before me.

Beep-beep!

Brumjam

Lightspeed would do just fine however my DAC has a volume control (and a remote because I'm lazy). If I sell the L300 I'll get at least half the floor space in my room back

Brumjam

It was your review Dave. Didn't make the connection until Alan mentioned it.

uglymusic

There you go. 

They must be good. I still have them :-)

Brumjam

These Hypex amps are so quiet. There is not the slightest hiss from my speakers and that's with my ear right against the tweeter. Great stuff. System is sounding rather fine today if I do say so myself

Alan

It must be satisfying like home cooking. I'm not likely to expeience that!

I might build an amp one day though!:D

Thanks for the update James, a very inspirational thread. If I hadn't comissioned an upgrade/rebuild of one of my amps I would be itching to have a go.

Jim

Good stuff James, yes they are very quiet.

I've also found them to be one of the most even handed amps I've ever used.

But have you enough power?

Brumjam

I think 200w per channel should be enough to scrape by Jim.......there's always biamping I guess  :-O

Jim

I keep taking the mick but I've got four 180w amps - each one directly driving a 15" bass driver
B-)

Brumjam

Ha!  That's what I would describe as 'adequate' power Jim.  Is that with a separate SMPS for each amp?

Jim

It is just about right.

No SMPS here.  Each amp has its own 500va traffo, double bridge rectifiers and in excess of 15,000uF.

Alan

Jim - you got any pics from the build?

Jim

I think I have somewhere...

Jim

Working out the layout:

http://i667.photobucket.com/albums/vv33/mjkempton/finallayout.jpg

Traffo, rectifiers and caps wired up:

http://i667.photobucket.com/albums/vv33/mjkempton/abouthalfway.jpg

I must be quite happy with them as I haven't touched any of them since I finished them 18 months or so ago.

Alan

We love pics. Only James knows what he's looking at but we still love 'em.

Jim

Thanks Alan

sq225917

I'm wondering why neither of these hypex builds connect the thermal transfer plates to heatsinks?

Jim

It is recommended that they are attached to sinks.  but I've never noticed excessive heat.  Always able to hold a finger on there comfortably.

And I'm lazy...