48 VDC/10 A power supply looking for an Amp design

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Greeting All!

Migrated over here from AK to see if someone might point me in the right direction to find an amplifier design to fit a power supply I recently bought....

here's the Beef...:D

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


I'm basically looking to try and build an amp to power the low end of a set of Infinity RSIIb's, which can drop to 1 ohm impedance during use. I have a Nak PA-5A II Stasis amp/Hafler DH-500 for the high end. As I understand it, this power supply is good for almost 500 Watts, but I'm really more interested in trading power for higher quality sound. I also have a friend who may be able to lend a hand, including making the PCB's etc....


Thanks!
 

taj

diyAudio Member
2005-02-23 8:49 pm
There are plenty of amplifier designs available here that work fine at 48 volts (assuming your supply is bipolar). But to drive a 1-ohm load it's going to require a lot of parallel output transistors (5 pairs?) to handle the current draw.

Is that 48v secondary AC or rectified DC?

Maybe the Delta Audio Leach amp (5 pair version). http://www.delta-audio.com/Leach-Clone.htm

FYI: I can't view your links as I'm not a member of that forum.

..Todd
 

megajocke

Member
2003-01-11 8:01 pm
"You are not logged in or you do not have permission to access this page. This could be due to one of several reasons:

1. You are not logged in. Fill in the form at the bottom of this page and try again.
2. You may not have sufficient privileges to access this page. Are you trying to edit someone else's post, access administrative features or some other privileged system?
3. If you are trying to post, the administrator may have disabled your account, or it may be awaiting activation."
 
I don't think...

...it's a bipolar design.

There are plenty of amps that can run from a single ended supply, but the Leach mentioned so far is not among them...

You can 'fake' a bipolar supply using a pair of huge caps and some bleeder resisters etc, but you would have a +/- ~24v supply. Not really a huge limitation if driving 1ohm speakers is your goal, but something to keep in mind.

Using a pair of bridged amps might be possible, since the outputs are then relative to each other, not ground, but AC or balanced input would then also be needed...AlephX springs to mind, or a pair of KSA50s.

HTH

Stuart
 
Hi,

Guess that supply will work just fine. It's quite large though.
Any single supply amp will work. (Do I dare mention FB-D-Amp).

-48V linear supply, sounds like some ancient telecom supply, in that case the output is likely to be slightly above 50V at lower loads and the output ripple and noise is very low.
Considering the size of the caps the above might be true.

/ Mattias
 
Simple workable example.
 

Attachments

  • example.jpg
    example.jpg
    24.9 KB · Views: 157
It might be worth examining the secondary of the transformer in this power supply, and seeing if it only has the one output winding, or two in parallel. If it has two in parallel, you could get 48V bipolar supply - at 5A per rail. As there are two capacitors (presumably in parallel) you could use those too.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.