What is this PS?

[S.C]

Is this a regulated power supply.


I am using it the run my Brain GC PCB because my powersupply section have been damaged.



Also look back to the unknown power supply pictures. There are a line of lights running across a panel. Will I be able to modify it to something like the level meter on some amplifier? ( those light bar will flash accordingly when music go thou the amp.) How do I do that?

[BlackDog]

Hi there.

It's not really possible to tell you exactly what your unit is doing without knowing more details of the main circuit board. - but from looking at the wiring in there, I would say that it's not designed for the currents necessary in a power amp.

[edit] - just had another look, and maybe the wiring IS thick enough.

You may be able to repair your BrianGT PCB by soldering a length of solid core wire over the tracks that have exploded.. Just make sure that you have fixed what caused the problem first!

Steve

[HDTVman]

The power supply in the picture looks like a "POWER ONE" supply. It is a regulated linear power supply. For the specs, remove it from the chassis it's in and the spesc are printed on the heat sink. That's the bottom plate of the power supply in the picture.

As for the lights do a search for audio level meters and you'll find all kinds of circuits that can use your leds.

Later
BZ

[S.C]

Ya it is a Power One Reg PS

And I intergrated this ps and my brian PCB into this cool case.

See more in here
The transformer will be in the center box after I finish everything.


Question: What will be the disadvantage comparing this Reg PS to a 25V25V +/- Torold (spelling) transfer + brian's ref PCB?

Anyway to improve the reg? use bigger transformer but how to do it?

[HDTVman]

SC

That Power One supply is not what I would use for a "gain clone".

The +/- supply only gives you 12 volt rails and at .4 amps.
the 3875 or 3886 chips can use much higher voltages than that and will require 10 times more current at least.

BZ's first rule of amplifers.

If you build a really good power supply then any amp can sound it's best.

It's just my opinion but I think that most of the difference that people hear in different amplifers is due to the power supply.

When I build an amp the first thing I do is figure out how much power I am going to need from the power supply. Then I double the current and that's what I build the power supply to put out.

I don't know what you expect from your amps but with that power supply you will not get much. Don't get me wrong, the power supply is a quality unit it just doesn't fit this application. There is no easy way to increase the output of this supply, it would be easyer to build one than to modify that one.

Good luck
BZ

[S.C]

I use it to drive two bookshelf speakers which connected to my PC. I think it is ok for my small room. However, I wonder what's wrong with the bass. I think this what my true question is. What will that small PS affect the quilty of the sound, beside loudness. I can also switch back to 25V +/- tor + ref pcb. IT just that I had too much of an error with the ref pcb haha. I always miss up when I put everything into the enclouse. However everything do work when I test it. I just finding a easy way out.

[rodolfo]

very small ps
small voltaje
small current
(sorry my inglis)

[HDTVman]

The bass problems you are having could very well be caused by the power supply. The 3875 chip has a minimum voltage requirement of +/- 12 volts. Below that point it shuts down to prevent turn-on/turn-off thumps.

With only 400 ma current output and operating at the edge of the amplifers voltage spec. as soon as the amp trys to produce any base energy the power supply drops and the chip shuts down. You just need more power supply. Both voltage and current.

The easy way out seldom pays off.

BZ

[Morse]

Hi S.C.

>>>...I use it to drive two bookshelf speakers which connected to my PC...<<<

While you can certainly drive a small chipamp to mediocre levels with that PS, why not build something a little gutsier for your project?

It's FAR from ideal, but a simple 25.2VAC @ 2A PS trafo feeding a fullwave bridge of FR306's can be built from parts you can find at Radio Shack for under $25, total (that includes the PS trafo, 2 packs of 3A rated power diodes - the blue ones with "FR306" written on the side sound fine, as do "HER's" - and a pair of 2200uF at 35VDC caps, bypassed by the 100uF caps on the chips). Of course all the usual provisos about "exercise extreme care when handling AC mains" apply (if you cannot SAFELY work with high voltage electrical circuits, then DO NOT BUILD POWER SUPPLIES!), and you MUST put in a fuse on the primary side of the trafo.

Anyway, I've built a number of TDA 2030's that use the PS as described, and it's adequate to drive a pair of those chips to about 16wpc RMS in my experience. Of course a bigger (and pricier) PS would be preferred for something like a LM3875 or LM3886 - but if all you can afford is the humble Radio Shack trafo, it's a start. For a little more "oomph" you could build a separate PS trafo per channel using the same components.....or even a 3 channel system, with a separate powered subwoofer.

And for a LOT more "oomph", look for a surplus trafo - size and current rating to be determined by the chip you want to use, of course.

One last thought concerns shielding - if the PS trafo is "unshielded" (i.e. there's no metal "can" around it) you will probably need to either put it in a separate subenclosure (vented for cooling is a MUST!!!!) and/or use shielded wire for the input leads. I've had some issues with "hum" pickup when using cheapie surplus unshielded PS trafos in the past.

Just some ideas.

Good luck and all the best,
Morse