Power Supply for multi-channel amp.

[wsmckenz]

Hello all,

New to the forums and haven't done much electronics for over 20 years, so bear with me. I'm looking at building a 12-channel amplifier (nothing audiophile, just stereo ceiling speakers in 6 rooms and it seems like I should be able to do better that $2000 for a Niles). I've done a little reading and researching, and it seems like building it using 3 of the following might be reasonable:

4*100 watt @ 4ohm, TK2050 D-class Audio Amplifier Board - eBay (item 220508931371 end time Jan-10-10 00:42:59 PST)

What I'm a little unclear on is the best way to power it. It seems like a single ps for all three boards would have to be pretty big, so maybe three matchign modular power supplies would work? Also not sure whether I am better off building the PS or buying something pre-packaged. Any pointers would be appreciated.


thanks, Bill

[sqlkev]

i'm somewhat in a similar boat
i'd like to cascade 3 amp modules (sure tk2050) with a single smsp (cheaper to just use 1 chasis)

do i get one with the highest amp ratings while keeping the voltage as recommended and wire the amps like this diagram? (page 7)

http://www.sure-electronics.net/down..._Ver1.1_EN.pdf

[authlxl]

Please look our new module,SMPS and Class D are in one board,use TAS5630,you don't need other switch power supply.

[fb]

authlxl,
Any more info on your modules?

[authlxl]

give me your Email adress,I'll send datasheet of modules to you,my mail:authlxl@gmail.com

[the7trumpets]

Wsmckenz, do you have any updates?

I have been thinking of doing the EXACT same thing for the EXACT same purpose (whole house ceiling audio), but with four of the sure audio TK2050 boards instead of three (16 channels vs 12). My main reasons for choosing this board are:

1. It gets good reviews for audio quality with only a few mods necessary
2. 30W of clean output power seems to be just about right (TPA3123 and TA2024 only provide ~4-6W clean power, and TAS5615 provides almost 100W).
3. It's affordable. $55 for 4 channels means the whole thing costs $220 plus the power supply, chassis, and connectors.


I'm really quite new at this, so I hope some other people correct me, but for power supplies, this is what I'm thinking:

I'm not planning on running it over 30W for sound quality reasons. The amplifier is spec'd at 88% efficient when running 60W into 8 ohm speakers. It will be a little less efficient at a lower power, so we'll say 80% at 30W. If I have 4 boards, that's a total possible 16 channels at 30W = 480W, divided by 80% efficiency and we need 600W input power to run all 16 channels at 35W.

Granted, the amplifier COULD draw more than that, especially if it were attached to 4 ohm speakers. To be super safe, I guess I would need 1600W divided by 90% efficiency (at 100W per channel into 4 ohms) = 1780W.

But I would have to have this thing outside before I could actually use 1600W of amplifier power without going deaf, and 2KW DC supplies are crazy expensive. So it seems to me that 600W plus maybe a little cushion should do just fine. Please correct me if I'm wrong though.


It seems there are two options: Multiple supplies or one bigger supply.

I've found the following single supplies:
$220 : MEAN WELL SP-750-27 : 27V, 750W
$120 : CONDOR GPMP900-24 : 24V, 900W
$65 - $115 : MEAN WELL SE-600-24 : 24V, 600W

And the following smaller supplies to double up:
$45 : MEAN WELL SE-350-27 : 27V, 350W
$40 : MEAN WELL S-320-24 : 24V, 320W


I'm leaning toward the Condor, just to be safe on the supply power. I realize I won't get quite as much output power at 24V (26V turned up) as I would from 27V (30V turned up) supply, but I have a hard time justifying an extra $100 for a little more output power that I'll likely not use.

If running it at 30V is really that much better than 26V though, I could get two SE-350-27 supplies and run two boards off of each supply. Doing so would require getting a bigger chassis, but I could make it work.



Any comments on running this thing at 26V vs 30V? I'd love to hear what you've done, hopefully it can help me too.

[gooki]

Originally Posted by wsmckenz

4*100 watt @ 4ohm, TK2050 D-class Audio Amplifier Board - eBay (item 220508931371 end time Jan-10-10 00:42:59 PST)

What I'm a little unclear on is the best way to power it. It seems like a single ps for all three boards would have to be pretty big, so maybe three matchign modular power supplies would work? Also not sure whether I am better off building the PS or buying something pre-packaged. Any pointers would be appreciated.

To be honest you'd probably be fine with a singe 350 watt Meanwell power supply, unless you like to listen in every room at super loud volumes.

Panasonic use a 175 watt power supply in the 7x100 watt classD receivers. Many other manufacturers take similar shortcuts. So if you want to go with the sure boards I'd try a single power supply first - you can always add a couple more later if you need it.

PS authlxl's 2x1500 watt classD modules with built in power supply are also good - I have two already and intend to purchase more, but it'll cost you more that the sure boards.

[the7trumpets]

Originally Posted by gooki

To be honest you'd probably be fine with a singe 350 watt Meanwell power supply, unless you like to listen in every room at super loud volumes.

Panasonic use a 175 watt power supply in the 7x100 watt classD receivers. Many other manufacturers take similar shortcuts. So if you want to go with the sure boards I'd try a single power supply first - you can always add a couple more later if you need it.

Thanks, that is exactly the kind of real-world advice I needed. I'm certainly not planning on listening super-loud, and knowing the big boys do the same thing helps put me at ease. One question though:

What would the failure mode be, if I tried to exceed the current capability of a power supply?

I want to make sure that:
1. It won't hurt the amplifier boards
2. It it is obvious when insufficient current is being supplied - would the power supply shut down? Or could I wire in a fault detection circuit to an LED that stays on until reset or something like that? What I don't want is for the supply to just limit the current and the amplifier to sound a little worse, but not 'really' be able to tell unless I'm listening very carefully.

Originally Posted by gooki

PS authlxl's 2x150 watt classD modules with built in power supply are also good - I have two already and intend to purchase more, but it'll cost you more that the sure boards.

Yes, they look nice, but the cost concerns me. The end cost would be about 50% more, and for this project I don't know if it's worth it. Plus, part of me would like to bolt it all together myself However, I imagine fewer if any mods are necessary on those boards, so I'll have to think about it.

[microsim444]

Originally Posted by authlxl

Please look our new module,SMPS and Class D are in one board,use TAS5630,you don't need other switch power supply.

That SMPS looks like those used in the VCRs very long time agoo. with STR main chip