Author Topic: POWER SUPPLY  (Read 271 times)

Offline Rhino

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POWER SUPPLY
« on: July 12, 2017, 01:12:03 PM »
I am looking at ordering this:
http://www.ebay.com/itm/LM1875T-Hifi-6j1-Valve-Drive-Power-Amplifier-Board-Kits-Headphone-Amp-Kits-20W-/352080833841?epid=18002647900&hash=item51f9a72d31:g:59AAAOSwpINZYtcZ

Small fun project for my office. (At least it is something better to look at than lines the whole day).

But I need a power supply for it.
Any advice or links please.

Thanks
Polk Audio Tsi500 - Fronts, Tsi200 - Bookshelf, Tsi100 - Front Height,  Cs10 - Centre, Integra DTR 50.5 AV Receiver,Sony BDP-S370 Blu-Ray, LG 3D Blu-Ray, Energy Veritas 10" Sub, Clavel 3 Way speaker

Offline gavinbirss

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Re: POWER SUPPLY
« Reply #1 on: July 12, 2017, 01:35:19 PM »
Power supply is a center-tapped or dual secondary transformer with enough current. (3A for amp and >0.5A for tubes, so approx 63VA at least)

It is going to be tricky getting the secondaries to stay within 18-19V AC.

2 secondary winding can be made centre tapped by taking the correct phase/s and tying 1 pair. This can be determined by measuring the AC voltage across a wire from each single wire until double the AC voltage is achieved.

From looking at other sources the 2 6J1 tube heaters are put in series and is rectified/smoothed to DC and dropped via resistor to around 12V. If fed by a 12AC secondary the filament buck resistor value needs to be changed.

There may be good substitutes for 6J1 tubes.

see : http://www.thetubestore.com/Tubes/1000-to-5999-Types/JAN-GE-5654W
« Last Edit: July 12, 2017, 01:43:03 PM by gavinbirss »