Two computer PSU's for audio power supply

tomaz · 15th May 2006, 01:43 PM

I am doing my first DIY audio amplifier and for a start I do not yet want to buy expensive transformers. I got some cheap AT psu's but do not know for sure how to use them.
Googling or searching this forum is hard because I do not really know what to search for.

The question is: is it possible to just connect the +12 of one PSU to the 0 of the other to get a -12 0 +12 setup? (or 0 +12 +24 which is basically the same)
This site suggests the 0 of the PSU is connected to the ground. I checked it and this is correct. Some insulating helps solving this problem.

But is this all I have to do? And the "first" PSU just "rates" the second from +12 (black wire, previously 0V) to +24 (previously 12V)?

Are there any sites that give a cleares explanation of the lot? I know about the load I have to put on the 5 and 12V lines.

N-Channel · 15th May 2006, 05:21 PM

Tomaz,

It is not that easy. The 0V lines of each AT supply are tied to earth ground. So, tying them in series, as you mentioned, would short out the output of one of the supplies, and let its magic smoke out.

Here is a thread at the Power Supply Design Forum that refers to bunch of threads regarding the use of AT/ATX power supplies for audio purposes.

SMPS questions

Hope this helps.

Regards,

Steve

kartino · 6th June 2006, 10:35 AM

N-Channel you are right,

I have simple solution. I give that solution to carlos (destroyer-X) at one of ss thread. (sorry... i miss that link). The modification is easy for everyone even they did not know smps. higher voltage are possible up to appx +/-30V.

You can connect two psu to get +/-12V but the one of casing (negative source) shall be isolated even to ground because the casing became -12V. Don't worry PSU always protected from short circuited.

cheers,

15th May 2006, 01:43 PM	#1
tomaz diyAudio Member Join Date: May 2006	Two computer PSU's for audio power supply I am doing my first DIY audio amplifier and for a start I do not yet want to buy expensive transformers. I got some cheap AT psu's but do not know for sure how to use them. Googling or searching this forum is hard because I do not really know what to search for. The question is: is it possible to just connect the +12 of one PSU to the 0 of the other to get a -12 0 +12 setup? (or 0 +12 +24 which is basically the same) This site suggests the 0 of the PSU is connected to the ground. I checked it and this is correct. Some insulating helps solving this problem. But is this all I have to do? And the "first" PSU just "rates" the second from +12 (black wire, previously 0V) to +24 (previously 12V)? Are there any sites that give a cleares explanation of the lot? I know about the load I have to put on the 5 and 12V lines.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
computer power supply?	bostonswoop	Chip Amps	29	25th April 2009 03:57 AM
Can i use a computer power supply to power audio amplifiers?	destroyer X	Solid State	91	25th September 2006 04:36 AM
Can you mod a computer power supply ?	ecman	Chip Amps	20	8th August 2004 07:47 PM
Car computer power supply	shyfx	Car Audio	3	23rd August 2003 05:10 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

15th May 2006, 05:21 PM	#2
N-Channel diyAudio Member Join Date: Mar 2003 Location: Sol System	Tomaz, It is not that easy. The 0V lines of each AT supply are tied to earth ground. So, tying them in series, as you mentioned, would short out the output of one of the supplies, and let its magic smoke out. Here is a thread at the Power Supply Design Forum that refers to bunch of threads regarding the use of AT/ATX power supplies for audio purposes. SMPS questions Hope this helps. Regards, Steve

6th June 2006, 10:35 AM	#3
kartino diyAudio Member Join Date: Feb 2005 Location: Gunungkidul Indonesia	N-Channel you are right, I have simple solution. I give that solution to carlos (destroyer-X) at one of ss thread. (sorry... i miss that link). The modification is easy for everyone even they did not know smps. higher voltage are possible up to appx +/-30V. You can connect two psu to get +/-12V but the one of casing (negative source) shall be isolated even to ground because the casing became -12V. Don't worry PSU always protected from short circuited. cheers,