PSU for HP Amp

[Pingushome]

Hi All,
Was going to use this circuit I found on the interweb for the HFW headphone amp by Richard Brice (printed a long while ago) with schotty doides and an extra 1000uf cap on each line in the HP amp and a maplins 30va 12v x 2, 1.25a tx (N20JB )
Thought it would be OK with a "value" dac on my PC usb line. I need 12v +/- at about 200/300 ma.
Any thoughts advice woul be appreciated.
It seemed like an inexpensive solution to a smoothed, regulated psu.
Martin
PS
I still have the article and diagrams if any one is intrested.

[colin.hepburn]

Hi i use this one which i build to power the buffer in my dac works well heres the link to it http://sound.westhost.com/project05b.htm

[colin.hepburn]

or this one which is for the JLH Headphone Amp

[Pingushome]

Thanks Collin,
I think i will use the first but leave out the adjustable resist bits and use low drop out fixed regs for the 12volts.
Would you know if I am right in thinking I can use a 12-0, 12-0 secondaries if I link them together (common ground) or do I have to get a Tx which has only 12-0-12v secondaries to get a +/- 12v supply?
Martin

[colin.hepburn]

Hi Martin
The regulator psu I posted in post two will be better than the one you posted
First the main large caps are configured in a pi filter
You could use bigger caps if you up rate the diodes
The minimum Transformer is 15-.0-15v
The parallel resistor pairs (R4A/B and R6A/B) are used so that you can tweak the output
voltage. Normally (for 15V), you would need to be able to obtain 1.1k resistors, but by using
a parallel pair, you can use 2 x 2.2k in parallel to get1.1k. For other voltages, see the table
below ...
Required R4A, R6A R4B, R6B Actual Voltage
± 5 V 330R 3k3 5.00 V
± 9 V 680R 6k8 8.98 V
± 12 V 1 k 6k8 12.15 V
± 15 V 2k2 2k2 15.00 V
± 18 V 2k7 2k7 18.13 V
Use matched resistors for R4A R6A R4B R6B
If you Want the build manual
PM me your Email and i will send you the PDF file

[Pingushome]

I've PM'd you thanks Colin
Martin

[colin.hepburn]

Martin you have mail

[Pingushome]

Diolch yn fawr Colin all is crystal now
Thanks

[Greg.]

I hope the Celtic Scotsman can read Celtic Welsh

[colin.hepburn]

Originally Posted by Greg.

I hope the Celtic Scotsman can read Celtic Welsh

Nope
but think martin is happy