Noob Question about Mini-A (I swear I searched)

[Patrick Bateman]

Do I have to build a power supply for a Mini-A? Couldn't I just buy a power supply that supplies +30V DC?

I'm not comfortable working with 120volts, since I'm a noob when it comes to amplifiers. I saw this completed circuit board for the Mini-A on Ebay, and it seems like all I would need is a 30V power supply.

Or am I missing something?

http://cgi.ebay.com/Class-A-power-am...4.c0.m14.l1262

Also, shouldn't the mosfet be attached to a heatsink? In the pic from the website, it's just sitting there on the circuit board, and I thought it would get hot as hell due to the low efficiency.

[leadbelly]

Originally Posted by Patrick Bateman

Couldn't I just buy a power supply that supplies +30V DC?

The short answer is no, you'll have to either buy or build a +/-18VDC power supply (or at least close to +/-18VDC).

Originally Posted by Patrick Bateman

Also, shouldn't the mosfet be attached to a heatsink?

Yes, you'll need a big heatsink for this when you build it out into a case.

[Andersonix]

I would say you're missing something: If you intend to buy stolen intellectual property, then keep it to yourself! Do a search here to see NP's and our opinions on those thieves.

[Patrick Bateman]

Originally Posted by Tosh

I would say you're missing something: If you intend to buy stolen intellectual property, then keep it to yourself! Do a search here to see NP's and our opinions on those thieves.

Actually that was the first thing I did - I expected that someone else would have a build thread already. But no hits on the vendors name were returned.

I thought these designs were in the public domain? But I don't want the thread to get off-topic, if the vendor is violating patents, I'll pass on it then.

[nicoch58]

Originally Posted by Patrick Bateman

if the vendor is violating patents, I'll pass on it then.

you must do ! or.....

[Patrick Bateman]

Originally Posted by leadbelly

The short answer is no, you'll have to either buy or build a +/-18VDC power supply (or at least close to +/-18VDC).



Yes, you'll need a big heatsink for this when you build it out into a case.

After digging around online, I found this:

http://www.headphone.com/products/he...wer-supply.php



It supplies +/- 15V, which is a bit low for the Mini Aleph. But I like the idea of not electrocuting myself enough to spend $500.

Thoughts?

My speakers are 104db efficient, so even a 10 watt amplifier is plenty.

[Beftus]

The mini Aleph (the Grey Rollins one) calls for a 15 volt supply. But is also runs on either 12 or 18 volts.

"I arbitrarily chose 15V rails, but it will work nicely as long as you're within shouting distance of that voltage. 18V? No problem. 12V? No problem. Just keep in mind that it's a class A circuit and it will demand roughly an amp at idle, every day, all day. Don't try to run it off a wall wart"

Nice looking PS, can it deliver ample current? At $500 a piece I'd seriously consider making a PSU myself for a lot less money.

[Bill Fuss]

Originally Posted by Patrick Bateman

After digging around online, I found this:

http://www.headphone.com/products/he...wer-supply.php



It supplies +/- 15V, which is a bit low for the Mini Aleph. But I like the idea of not electrocuting myself enough to spend $500.

Thoughts?

My speakers are 104db efficient, so even a 10 watt amplifier is plenty.

There is an entire forum on power supplies!

If you are serious about entering the DIY world you need to get serious about building stuff for yourself, not using stuff that was stolen and reproduced for profit. There is plenty of info and help available on these forums to keep you out of trouble.

There are no shortcuts, read and ask questions, then read some more. It takes time, not money. The stuff you build yourself always sounds better than the stuff you buy.

The mini-A is a serious amp that requires a robust PS, I doubt that the Headroom PS is even close to being large enough. I couldn't find any rating for it. 6 Amps would be a good number to shoot for, for a stereo amp.

Best, Bill

[vdi_nenna]

Order some boards from www.chipamp.com http://chipamp.com/orders.shtml or Audio Sector's Peter Daniel. Contact Peter through email on his site. http://www.audiosector.com/

The mini-a doesn't require adjusting, so it's a bit easier for a newbie. Find all the parts from Mouser and Digikey, solder them yourself. You're gonna have to learn somehow, so you better off starting with a project like the mini-a. You're gonna need large heat sinks, so off the top of my head, you can get a set from apexjr.com that will do the trick. Check out Antek Transformers for a 12+12V, 8 amps or more. There's also Plitron and Aval-Linberg.

There are videos on the internet on how to solder electronics. It's not that difficult.
Passdiy.com has a written tutorial.

Just remember to be safe and always keep your hands clear of exposed parts, especially in the power supply.

[vdi_nenna]

Just remember to be safe and always keep your hands clear of exposed parts, especially in the power supply. Don't power it up until you have everything wired up, then stand back. Fire it up. If no sparks, check for burning smell, if no burning smell, you're half way there! Check voltages according to schematic and article. check for high DC at output. Never hook up good speakers before checking DC. Remember voltage are stored in power supply capacitors that can melt the tip of a screw driver. Not to scar you, but you need to know! Always check with a meter before going back into a circuit. Always! Always unplug the amp before starting to troubleshoot. If you are going to noodle around with your hand or screw driver, put your left hand in your pocket, use your right hand. Someone jump in at any time if this is bad advice. It's kept me alive so far.