Anyone making SMPS for power amps?

[mr.duck]

Hi, I've been looking for a SMPS to power audio power amps. Coldamp.com make some SMPS that look pretty good, except they are rather expensive and output voltages are too high. Ideally, I'm looking for +/- 24v with about 5A for stereo should be enough to play with (240W output). I know of the skynet 8080. Price is right but it would take 4 of them to get +/- 24 and that would be too big.

Is there anything else out there I've missed? +/- outputs is the main thing that most SMPS lack. I would just design my own SMPS at this point, but I can't lol

[rcavictim]

There is a very informative thread about this subject here already. I am building a PWM controller for a DIY EV and found it informative in a related way. Try a search.

[mr.duck]

Hi, I've been reading many past threads but the search returns hundreds even when just searching titles. I've probably missed the thread you speak of. Please post a link if you have it, thanks.

[rcavictim]

Here is the one I was referring to.

Making car amplifier SMPS with tl494 + DC Protection

[AndrewT]

Hi Mrduck,
in two words:-
forget it.

[mr.duck]

Hi, Andrew. I think you're right. Back to the linear regs I go

[FastEddy]

well, yes you can forget it unless your purpose is specialized like weight restrictions, etc.

This one seems to work quite well: dual + 48 VDC isolated output for +/- 48 VDC rails. The extra torrid hum bucking inductors and the extra 1500 uF 100 volt electrolytics keep the output very quiet indeed ... total weight about 15 pounds ... ("flat pac" topology useful in 1 Up rack mounted chassis from: http://www.vicr.com/products/configurable/flat_pac/ )

[AndrewT]

Originally posted by FastEddy
well, yes you can forget it unless your purpose is specialized like weight restrictions, etc.

This one seems to work quite well: dual + 48 VDC isolated output for +/- 48 VDC rails. The extra torrid hum bucking inductors and the extra 1500 uF 100 volt electrolytics keep the output very quiet indeed ... total weight about 15 pounds ... ("flat pac" topology useful in 1 Up rack mounted chassis from: http://www.vicr.com/products/configurable/flat_pac/ )

From a man/woman who knows what they are doing.

What hope have you got when you don't have the resources to design the supply nor how to start modifying it.
And what if it needs debugging after assembly?
And then will it sound OK?

[FastEddy]

" .. What hope have you got when you don't have the resources to design the supply nor how to start modifying it. ..."

? Resources: costs each manufactured supply module ~ US$180.00 delivered (X 2) ... (DIY SMPS's from ground up would have cost much more, considering design time, mfger time, assembly time, parts ...). These supplies are "hospital grade" intended for industrial applications like running motors & ultra sound scanners, etc. Note also lab equipment grade EMF filter on line cord and circuit breaker / power switch (usually a no - no for golden ear gear), but no EMF allowed in or out of the box. I am using my own "secret sauce" on the supply outputs = those counter wound humbucking torrids knock almost all of the residual switching supply noise off of the power rails. The interconnecting power & speaker wiring is fine strand #12 AWG silver, teflon coated, likewise input signal wires are of shielded stranded silver / teflon wire from the gold plated RCA connections to the gold plated amp module connections ... which rmay or may not do much, but the customers love it. (The interconnects and amp modules are more co$tly than the power supplies.)

" .. And what if it needs debugging after assembly? .."

? So far all switching supplies have passed muster = no worry mate, no failures, no excessive heat, no bad news ...

This dual channel amp is for a special project to be sold when (or if) it passes all the tests. These are 500 watt into 4 ohm MOSFET amp modules, downgraded in output to about half that for thermal reasons, mostly = to be run 24/7/365, hopefully without any hangups, ever. Another model will use open frame + 60 VDC X 2 SMPS modules for +/- 60 VDC rails and closer to 350 watts per channel ... but weigh a little less = 14 to 15 pounds (!)

" .. And then will it sound OK? ..."

So far they sound just great = healthy, plenty of guts, tight bass, clear highs. The ultimate customers are professional musicians, needing guitar power that does not require its own airline tickets to travel ... The one pictured has not been final assembled as yet nor undergone burn in or amp bias tweak ... My 'scope pictures look about as good as these: http://aussieamplifiers.com/nx500ln.htm

(I'm working up a vacuum tube pre-amp with switching supplies = a serious violation of audiophile conventional wisdom ... )

Anyone know where to get thin sheets of teflon?? about 8 1/2 x 11" ??

[AndrewT]

Hi Fasteddy,
I was talking to Mrduck, using your example & expertise as an example of what is needed to get started down the regulated route.

The resources necessary include that expertise (not the money).
Without it, one is struggling.