DIY Battery power supply (PSU) for hiFace Evo – part 1

hiFace Evo has huge variety of inputs and outputs
hiFace Evo - Hi-End S/PDIF Output Interface

I’m proud owner of hiFace Evo S/PDIF Output Interface and there is possibility to use battery PSU. Why spend £300 for original Hiface Evo power supply, when you can make your very own one for fragment of the price?

Operational wise advantage of original EVO psu is that you can switch between battery operation and power from charger (which has some low noise regulator I believe). Mine can switch between Battery / Charging and ON/OFF. I could probably go for low noise LT1764 – PDF Datasheet regulator or something, but then it would lost its main purpose – DC power.

Evo Supply – original webpage
I very appreciate website of hiFace company, thy provide us with nice specification and don’t try to hide behind curtain of misery unlike some of high-end manufactures.

Original EVO supply
Evo Supply - High Performance Power Supply

As usual I have started with little research and find out:

  • Very high precision, very low phase noise (jitter) crystal oscillators are used. To further improve their performance, they have a dedicated shunt voltage regulator which ensures a very low noise and spurious-free supply. hiFace Evo is powered by an external power supply (not included), to avoid the dirty USB bus supply from negatively affecting hiFace Evo’s performance. Linear regulators are used all around, to allow all jitter-sensitive digital circuits to operate at their best. Also, a low-pass filter is provided at supply input to further reduce any bad influence from
    the supply.- So there was my answer – I don’t need to use internal regulator, because Evo has got one qulity already.
  • Can be powered by an external wall adapter (9V 1A will fit), or with a 9V alkaline battery, or with a 7.2V/10.8V Lythium battery. Again – answer is here: huge variety of batteries available. I went for RC car NiMh battery.
  • hiFace Evo spec: 7-11VDC (15VDC max.), Supply current: 140mA (idle, no output connected)
  • EVO supply spec: Supply voltage: 15VDC; Supply current: 2A peak; Output voltage: 9-11V (battery directly connected to output); Output current: 1A peak, 500mA continuous

Depends on the chassis and connectors PSU can cost you between £20 – £60 to make. I went for cost no object version.
List of parts:

  • Thin Wall Diecast Aluminium Project Box 145x95x49mm
  • Ansmann RC Car 7.2v / 3000mah NiMH Battery
  • Ansmann Racing Delta 6 Pro Charger UK with Tamiya connector for use with 6 cell NiMH/NiCd battery packs
  • Self-adhesive feet 6.0 x 3.0 mm
  • 1/0.6mm Circuit Wire Red
  • 1/0.6mm Circuit Wire Black
  • Mini Toggle Switch DPDT ON – ON
  • Mini Toggle Switch 3A SPST ON – OFF
  • 2mm Flat Top LED Red
  • 25 x 64 mm Stripboard PCB Prototyping Board
  • 2x 100 Ohm 0.5W resistors
  • 3x Mini XLR socket, Neutrik
  • 2x Mini XLR plug, Neutrik
  • Paint spray
  • Engraved badge

Few notes to battery:
– Battery is well in limit, it is charged on 7.8V and is able to supply up to 18A current. (Measured with my poor multimeter)
– Original EVO PSU has 2300 mAh battery, so this should be an upgrade.

Battery and charger bought in £27.99 pack from RC Geeks UK on eBay
Ansmann RC Car 7.2v 3000mah Battery & Delta Pro Charger

Yes, it is really working – sound is smoother with same amount of details. I’ve just connected battery to hiFace Evo. Profi job – twisted wires 🙂
DIY Battery Evo supply

Testing my idea.
DIY Battery Evo supply

Don’t forget to check out part 2 and 3 if you want to know more.
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