For the record, with a 19V supply, the only way you'll get 50W into 8ohms is with heavy clipping (ie. THD well over 10%) - see Figure 7 on page 8, in the datasheet, and divide the power by 2.
19V will get you a clean-ish 20W into 8ohms.
What's your signal source, that's so "wimpy" (regarding output voltage)?
19V will get you a clean-ish 20W into 8ohms.
What's your signal source, that's so "wimpy" (regarding output voltage)?
With 19V there isn't anything you can do with the gain, it will just clip, the limit is acutally the rail voltage. You could raise the power supply voltage but with that laptop power brick you will not get more power. So yes, it is indeed an amplifier mismatch, that sure amp is a PBTL board specifically built for high power at low impedances.
Thanks for all the quick replies!
So I need to consider another amp.
I was hoping a class D amp since they're cheap and the TPA3116 has had decent reviews.
But I've been reading, since purchasing a few of these amps and I may have another problem. In class D there is a master/slave clock option. I'm using these amps on 12 driver arrays. Should I just steer clear of class D and go for an amp based on a LM3886? Or any other ideas?
So I need to consider another amp.
I was hoping a class D amp since they're cheap and the TPA3116 has had decent reviews.
But I've been reading, since purchasing a few of these amps and I may have another problem. In class D there is a master/slave clock option. I'm using these amps on 12 driver arrays. Should I just steer clear of class D and go for an amp based on a LM3886? Or any other ideas?
Nothing wrong with class D. I'n using TPA3116 amps in my 5.1 system also running a 19 Volt 9.5 amp power supply. It does just over 20 Watts per with 8 ohm loads - more than enough for TV. The 3116 is limited to 26 Volts which limits the power.
If you need more power, TI can get you to 300 Watts at 4 ohms, half that at 8 ohms. After building linear high power solid state amps, chassis, heatsinks and power supplies are big and expensive and quite a chore. A class D amp with comparatively SMALL heatsinks and switching supplies are far smaller, lighter and less expensive and vastly more efficient. You can buy an assembled and tested TPA3255 board on eBay for < $60 out the door.
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Thanks guys. I just found me another PS brick on eBay for $20ea rated at 6A at 24V. I may still go the lm3886 route. If I do, it'll be Tom Christiansen's Neurochrome 40W Amps. But for now, I'm going with what I currently have: 12x Sure 100W TPA3116, 3x minidsp2x4, 3x 24V 6A PS. I'm building the 3rd box which contains 4x Sure amps and a minidsp2x4. Hopefully 6A will be enough to power 4 Sure amps.
~150W for 20$, you say? Straight from China, i assume? And lemme guess, no particular brand name either, right? That's just downright scary... And why not, perhaps even a potential safety / health hazard.
Yes, that is indeed the case with bottom-of-the-barrel stuff from the far east, that you plug into the mains, unfortunately.
Yes, that is indeed the case with bottom-of-the-barrel stuff from the far east, that you plug into the mains, unfortunately.
Not FROM China, but most likely MADE in China. Here is a similar link. Apparently made to power LED strips.
Also, I did find a 'real' SMPS 24V 15A for $25US ea, but I would have to wire to I/O, whereas the 'bricks' come with long AC cords and barrel connector out.
Oh, the irony - minger - Wiktionary
AC cords are detachable / replaceable, and cheap, so i'm afraid that argument doesn't stand
That being said, that brick looks like the size of... maybe a 65W laptop brick, definitely smaller than a 90W one. 150W out of that? I have my doubts; on the other hand, on the bright side, at least it wouldn't be subjected to continuous full load. I wouldn't be surprised if it was half-empty on the inside anyway. Doesn't make it any less of a death-trap though.
PS: You'd get a clean 30W into 8ohm @ 24v, as opposed to 20W @ 19v, but that works out to a difference of about 1.5dB SPL, so there's not THAT much in it, imho.
AC cords are detachable / replaceable, and cheap, so i'm afraid that argument doesn't stand
That being said, that brick looks like the size of... maybe a 65W laptop brick, definitely smaller than a 90W one. 150W out of that? I have my doubts; on the other hand, on the bright side, at least it wouldn't be subjected to continuous full load. I wouldn't be surprised if it was half-empty on the inside anyway. Doesn't make it any less of a death-trap though.
PS: You'd get a clean 30W into 8ohm @ 24v, as opposed to 20W @ 19v, but that works out to a difference of about 1.5dB SPL, so there's not THAT much in it, imho.
1.5dBx12 (per side)Oh, the irony - minger - Wiktionary
AC cords are detachable / replaceable, and cheap, so i'm afraid that argument doesn't stand
That being said, that brick looks like the size of... maybe a 65W laptop brick, definitely smaller than a 90W one. 150W out of that? I have my doubts; on the other hand, on the bright side, at least it wouldn't be subjected to continuous full load. I wouldn't be surprised if it was half-empty on the inside anyway. Doesn't make it any less of a death-trap though.
PS: You'd get a clean 30W into 8ohm @ 24v, as opposed to 20W @ 19v, but that works out to a difference of about 1.5dB SPL, so there's not THAT much in it, imho.
I think you're right Khron, but I'm going to start there. With these cheapie PS bricks, at 6A powering 4 boards they may be lacking current. If this turns out to be the case at louder volumes I'll gladly pay 5 more dollars per power supply for the 24V15A units I linked to above.
24V is the max rated volts for these Sure Amps, although 26V is max rated for the TPA3316. Any comments on this? Just a safety margin.
24V is the max rated volts for these Sure Amps, although 26V is max rated for the TPA3316. Any comments on this? Just a safety margin.
Power / current is only one side of the issue. The other one is the safety factor.
If anything, i'd rather go with browsing the used market for brand-name laptop chargers - HP, Dell, Lenovo, even Asus. Most of those (that i've seen, at least) are made by only a handful of reputable OEMs, usually Delta / LiteOn / AcBel / Hipro and have been (legitimately) safety-tested and whatnot.
But hey, if you're willing to take that gamble for a couple bucks, what can i do to stop you?
PS: You never linked any information about that 15A supply, only the 6A one.
If anything, i'd rather go with browsing the used market for brand-name laptop chargers - HP, Dell, Lenovo, even Asus. Most of those (that i've seen, at least) are made by only a handful of reputable OEMs, usually Delta / LiteOn / AcBel / Hipro and have been (legitimately) safety-tested and whatnot.
But hey, if you're willing to take that gamble for a couple bucks, what can i do to stop you?
PS: You never linked any information about that 15A supply, only the 6A one.
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