DIY Amp build

3 way active? What are you using for DSP, keen to get into active but seems v expensive. Although allows for easy manipulation
atm it's passive but the purpose of the extra amps is to go active, I use a PC as a source so DSP is there (using acourate for filter design)
 
the need for overkill took over so order placed for 3 x NC400 + SMPS3kA400 + another modushop case

this one should be much quicker to assemble, just need to drill a few holes in the base to mount the thing & twist a few wires and that's that
 
Hypex kit arriving tomorrow :thumbsup:

Case seems unlikely to make it here til next week though so no bank holiday amp build for me!
 
annoying wiring situation with these amps, I either have to construct some custom loom to join 2 different molex type connectors to each other or shell out for a couple of these DIYclassd.com

convenient but no doubt means an excess of wires (as the cables will be too long)

alternatively I have to construct something to bridge from a big 6 pin connector and a 10pin ribbon cable to a single 12 pin molex, basically taking some of the cables from the big white one and the small black one to one of those bigger black ones. The ribbon cable is the annoying one as it is pretty damn fiddly to strip them down into separate wires

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anyone know of a good way to splice a ribbon cable?
 
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Hi Matt, you probably already know of these but they may have a combination of connectors that would help you out, I use them fairly often & they are good quality.
 
I used these in the previous build but then I needed just 1 pin from the ribbon cable which meant cutting a ribbon cable in two, using a craft knife to slice apart the individual wires then burning off the insulation from one pin. I then had to fold the wire back on itself a few times to thicken the wire as it was only 28awg and the wago blocks go down to 24. It works but a bit of a faff.
 
Nice find, you could attach them together with double sided pads to make a strip & keep it neat, the gorilla glue brand pads I’ve found to be reliable.
 
the wiring is actually a bit different than I thought so there are 3 different output connectors on the SMPS to use, 2 different ribbon cables (marked as J3 and J4 below) and 1 chunkier cable (J1). Seems a moderately confusing way to do this!

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rejigged the rack to make room for 2 more amps

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am returning the 2nd motu interface as they seem really flaky when paired via AVB, one would work but not the other

returned the old RME to duty and connected it via ADAT to the motu for clock sync, hopefully that is more reliable
 
case arrived early so spent the day getting most of the 2nd amp put together, still managed to cut the signal cables too long despite thinking "must not make these too long this time" :facepalm:

everything else pretty straightforward, partly a result of having just done one and partly because the nc400 modules are a much neater package due to the integrated heatsink
 
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Managed to fat finger order the a700 smps rather than a400, expensive mistake averted and soundimports been v helpful with returning it. Ordered an a400 to replace so hopefully that lands by the weekend.
 
Very nice & tidy Matt:thumbsup:
I would really like to build my own 8 channel Ncore amp to drive my surround/Atmos channels at some point, not that there’s anything wrong with my AVR driving those channels, it’s just somehow more satisfying knowing you built it yourself.
 
sweet build. i my self built a 3xnc400 amp not long ago i went the lazy route and got the case from ghent audio. which psu did you end going for ?

i will need to add a fan at some point to min though last week it began to over heat.

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Hi Matt,
How are you getting on with your amps?

I’ve started investigating lower cost options (than Hypex) for an amp to drive my surround channels, 3eAudio TPA3255 boards are looking like a decent option, along with a Meanwell LRS 350-36 power supply per amp board, I’d value your thoughts on that combo if you get a spare moment?
 
I don't know too much about them, specs seem a bit silly rating to 10% thd :suicide: but if they have enough clean power then am sure they will do a decent job. Possibly noise level might be more important here as surrounds are typically closer to you though i guess that also depends on how sensitive your surrounds are.
 
I can't believe I missed your thread, Matt. Good for getting it done - I recall you posted in mine too.
I need to get that up and running again - been busy with work and not had the time to sort stuff out.

I still have a collection of cases I need to find a use for! :D
 
thread necro ftw

for various reasons (time mainly, I never found the space or inclination to spend many days overhauling the entire setup) I only just got these into play

a few things I learnt along the way

  • pads for your XLR cables are cheap and easy to DIY (~£3 for some connectors, a few quid for so many resistors you can open a shop)
  • if I did it again, I'd find a way to put the pads inside the case though as externally, they're a bit in the way
  • no matter what you do, wiring many multiway speakers is a total nightmare and makes a mess (though less of a mess than having external crossovers nearby)
  • these hypex amps run hotter than I was expecting when not doing much
  • I did nearly deafen people at one point, remember to turn off your audio interfaces if you have a partially working system that you need to leave unattended!
  • the amount of overkill I have now on the amps is a more than a bit silly, on reflection I don't even need a unity gain buffer for the CDs (amp has 25.8dB gain, I pad them down by ~22dB and I still have +10dB excess headroom over and above that padding) and the woofers are pretty excessive too (amps sized to be able to join in with the subs but measurements say I have no need for that).
  • a rough and ready crossover (eyeball a few filters, done) sounds totally fine for a quick setup, admittedly the eyeballing is based on measurements that took some time to make so they're not exactly guesswork but still, if you get tired of faffing around with your rack and wiring stuff up then you can get something going easily

and, of course, veils have been lifted since switching over

the woofer overkill means I might sell the cinepro I'm using on the woofers and build something else smaller (3 monoblocks probably), the space saved means I could introduce a bit more space between items in my rack though not sure heat is really a problem anyway (the rack is open after all)
 
I still need to get the active fir xos with driver linearisation done, I have designed them but just need to get the measurements complete to create the actual filters. Hopefully this weekend....

after that, I plan to try the IIR linear phase filters mentioned in Why not IIR filters + a global phase linearization by FIR for live use (I route live tv through this system)
 

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