Easiest way to supply +-60 and +-45 for cheapie ebay amp?

[sall]

Hi Everyone,

I apologize if I'm in the wrong place -- I'm a newbie that's trying to repair a dead subwoofer that was given to me. It was a pretty cheap one, and I was going to replace the amp completely.

I found one on ebay that's based on the LME49810:

LME49810 Top Audio Power Amplifier Kit Board Mono 300W | eBay

... I'm just trying to figure out what else I need to do with it to get it all together and working. :-) I need to supply it with +/- 60V, as well as +/- 45V. What's the best way to do that? My best bet that I can see is to get a big 42-0-42V toroidal, as well as a 32-0-32V, rectify and smooth them, and we're all done. Is there any other quick, easy, and cheap ways to get a supply for something like that?

Also, I'm not as familiar with the circuit design -- there's a link to the schematic on the listing (which is here: http://www.kcheungshop.com/supports/...a_24v_300w.jpg). I assume I'll need more (all?) the power on the 45V line, but how much will I need on the 60V lines? Can I somehow get away with only a single transformer or value, or do I have to have both 60 and 45V for the board?

Thanks in advance for any advice anyone can give.

[Ampit]

Really complicated this might be. You will need a big heatsink, too. Ans remember that you will hardly be able to use the power supply together with any other amp you might buy in the future. Perhaps better to search for another board?

[Andy5112405]

Yes you could use a single 42-0-42V toroid. However, 42 is not a common UK standard. You will probably have to forgoe a minor amount of power and go for 40-0-40.

Wether it is cheaper to produce 2 x regulators to feed the +/- 45V or just to get another transformer depends on the currents involved.

I would suspect that the +/-45V is for the power output devices and the +/-60V is for the drive stages if it is a MOS-FET amp. In that case I would stay with two transformers.

Why not try a few e-mails to the transformer manufacturers. A single transformer wound especially may be comparible in price to two commercially available units.
I was quoted £200 for two 42-0-42V 500VA transformers - so £100 each. That is comparible with buying 2 x commercially available 500VA units.

[sall]

Originally Posted by Ampit

You will need a big heatsink, too. Ans remember that you will hardly be able to use the power supply together with any other amp you might buy in the future. Perhaps better to search for another board?

Oh, yep, I forgot to mention the heatsink, but I've got that covered -- got a few big whoppers sitting around somewhere. :-)

I don't really have any interest in reusing the supply -- I just want to build something suited to this, that I can package up in the sub enclosure with the amp, and be done with it. Mind you, I'm not 100% set on this board, either -- do you have any other recommendations for a reasonable sub amp that might be easier to power?

[sall]

Originally Posted by Andy5112405

Wether it is cheaper to produce 2 x regulators to feed the +/- 45V or just to get another transformer depends on the currents involved.

I would suspect that the +/-45V is for the power output devices and the +/-60V is for the drive stages if it is a MOS-FET amp. In that case I would stay with two transformers.

Hmm -- I know I'm showing my ignorance here, but why do I even need 2 different voltages for the board? ie. why can't I run it all on +/- 45V, or 50V, or something like that?

I haven't had any experience in audio electronics, so I realize this is probably a dumb question -- do you have any pointers on any good tutorials that cover this sort of stuff from the start? *grin*

Thanks in advance for any help and advice!

[Kjeldsen]

Personally I would go for at complete "plug and play" amp like these

Amplifier store Small Orders Online Store I don't know any australian distributors but we have one in Denmark (Welcome to CAD AUDIO DK)

or
Connexelectronic