Ultra-cheap Digital Active system blog


#1

I’m going to document my next build, which will be a digital active system that is as cheap as I can manage.

Here is the system at present: there is a Squeezebox Classic, which feeds a class D chi-fi amp and then Heybrook Sextets.

Things are a bit untidy, so I’m going to build a system that will fit to the left of the TV, on the white shelf. There is a space about 26cm deep and 36cm wide, with no real height restriction.

The system I have planned is as follows:

  • Intel NUC as player
  • Asus Xonar u7 sound card
  • 3 x Chi-fi TA2020 amp boards
  • The Heybrook Sextets, suitably butchered

The NUC should be capable of FIR filters, running a convolver in Reaper or JRiver. The sound card is capable of 24/192 (although the NUC probably won’t be able to process at that rate, we’ll see) and sounds pretty good. The amps are low power (about 6W really), but I generally like the sound of TA2020s, and this system will never go loud. It’s my Sunday morning system.

Progress will be slow, not least because the amps will take a month to arrive.


#2

Here’s a rough BoM:
Intel NUC NUC6CAYH - £170 used 11.6 x 11.1 x 5.1cm
Asus u7 £38 used 130 x 80 x 25 mm ( L x W x H )
Logitech K400 keyboard https://www.ebay.co.uk/itm/112800009499 £20 new
TA2020 board https://www.ebay.co.uk/itm/264080460920 £9 each 76x62mm, 27mm high
6mm coupler https://www.ebay.co.uk/itm/111956784105 £2 have 2 already

To order still:
Power supply: https://www.ebay.co.uk/itm/173417690124 20A £15 194(L) x 110(W) x 50(H) mm (12V 20A 240W) 689g
Alu rod 300mm: https://www.ebay.co.uk/itm/323175383233 £4
Knobs: https://www.ebay.co.uk/itm/120800879328 £2 each
25cm USB cable: https://www.ebay.co.uk/itm/382439532946 £2
USB fan: https://www.ebay.co.uk/itm/202388601569 £2
Mains inlet: https://www.ebay.co.uk/itm/121819925781 £6
25cm jack-jack cable: https://www.ebay.co.uk/itm/254154547899 £1
25cm jack-RCA cable: https://www.ebay.co.uk/itm/231591286249 £2
Six core speaker cable: https://www.ebay.co.uk/itm/283207418699 £4/m

I have some 12mm ply that I’ll use to house it.

All in all it should come to under £300


#3

What did you pay for the Sextets Adam?


#4

They were just £200.

There’s an issue with one of them not being quite balanced. The drive units all make noise, but one is quieter at some frequencies. I could measure and try to work it out, but instead I’ll just bypass the XO and see if that fixes it. It’s probably an old cap. I hope!


#5

Good price. A fair bit of speaker for that money :+1: