Looking on Mouser, it looks like the LM3886 is the most powerful class A/B chip amp. I see others that claim higher power but the specs are inflated. It looks like there isn't an option that can handle 100W in a gain clone. I guess it's just too much heat for 1 chip alone.
How about class D? Does anyone here know of the most powerful class D option?
How about class D? Does anyone here know of the most powerful class D option?
Big problem is package thermal resistance.
Since it´s basically the same as 2 TO220 cases side by side, you can´t expect wonders.
Both TDA728x and LM3886 have same case dimensions, so same thermal resistance to heat sink.
LM3886 is known for its ruggedness, whiloe TSA has a long track of failures.
Not surprising: LM claims 50/60W output and obviously can handle that; TDA claims up to 100W per chip ... and fails regularly.
I use them to get 70W and then work fine.
As of chipamps, there are way larger and more powerful, they are physically larger of course, check the very popular Sanken STK series.
I know up to 200W RMS ICs, used in PA and Bass amplifiers, there might even be larger ones.
Of course, they are as large as the palm of your hand ... which is fine, in any case they must be bolted to an even larger heat sink.
Since it´s basically the same as 2 TO220 cases side by side, you can´t expect wonders.
Both TDA728x and LM3886 have same case dimensions, so same thermal resistance to heat sink.
LM3886 is known for its ruggedness, whiloe TSA has a long track of failures.
Not surprising: LM claims 50/60W output and obviously can handle that; TDA claims up to 100W per chip ... and fails regularly.
I use them to get 70W and then work fine.
As of chipamps, there are way larger and more powerful, they are physically larger of course, check the very popular Sanken STK series.
I know up to 200W RMS ICs, used in PA and Bass amplifiers, there might even be larger ones.
Of course, they are as large as the palm of your hand ... which is fine, in any case they must be bolted to an even larger heat sink.
Thanks for the insight JMF, I didn't know that about the unreliability of those chips. I'm having trouble finding the STK series from a vendor. The most powerful class D chip I've found so far is: http://www.mouser.com/ProductDetail/NXP-Semiconductors/TDA8954J-N1112/?qs=sGAEpiMZZMtxdzBvM0rKcbaYt4XXYNSfuKhFKotYIUw%3d
210W/ch @10% THD, doesn't list power at lower levels.
210W/ch @10% THD, doesn't list power at lower levels.
Apex Microtechnology if you count that.
https://www.apexanalog.com/products/linear_selector.html
They list power op-amps at 500W power dissipation.
https://www.apexanalog.com/products/linear_selector.html
They list power op-amps at 500W power dissipation.
BTL 3886 circuit for 8 ohm speakers with a friendly impedance curve will get you 100 watts RMS per channel super clean. It's rated as high as 138 watts RMS in bridge mode, theoretically. You can run it in BTL mode with a little lower voltage to reduce the amount of heat produced and give you a little breathing room for speakers with less friendly impedance curves. Keep in mind that some 8 ohm speakers dip below 6 ohm; most speakers rated "4-8 ohm" are really 6 ohm (or sometimes dip below 4 ohm- no problem for some amps and big problem for others) and 4 ohm speakers are out of the question with BTL. A very popular speaker manufacturer is well known for advertising bogus impedance specifications (as well as other specifications) and some of us know who that manufacturer is. They think we can't do basic measurements on their products and separate fact from fiction.
You can parallel devices but this is not as straightforward. Neurochrome sells LM4780 parallel amplifiers that are available for a limited time, because the 4780 is end of life.(You should check the website out; there is a lot of information about chip amps there, as well as boards etc for sale there.) Parallel amplifiers can easily deliver 100 watts+ into 4 ohms.
You can parallel devices but this is not as straightforward. Neurochrome sells LM4780 parallel amplifiers that are available for a limited time, because the 4780 is end of life.(You should check the website out; there is a lot of information about chip amps there, as well as boards etc for sale there.) Parallel amplifiers can easily deliver 100 watts+ into 4 ohms.
Pick one, it doesn't matter to me what the metric is. Relative to each other there is one that puts out the most power and I'm curious what the options are for both A/B and D.
Fast Eddie, thanks for the information that definitely helps.
DUG, do you have a source that you would recommend for buying the high power op amps?
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For class D, how about three ICs? A driver + two MOSFETs/channel for 500W?
International Rectifier/Infineon IRS2092
International Rectifier/Infineon IRS2092
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if all you want is to get the most power, than class D is your pal.
if we are allowed to go with unusal impedances as load, you can squeeeeeezeee out killowatts from class D amps and mosFets without issues.
the limitng factor is the output voltage of the chip, from then on mooar output devices will yield moooar powa.
in class AB it can be simular, but harder to do.
bridged and paralelled chips that have slave/master mode make things less problematic, however roughly 500 watt is the feasable design.
discerte designs while certainly harder, can offer anything you like.
one of the lunatic solutions of the end of the tube era used tubes for voltage gain, and the output devices where so silly that the unit featured NO trnformator. basicly it was able to throw whatever you main powerlines where able to provide.
s the output swing was 200 voltish, and if you lost your brain somewhere in theory it was able to spit 6 amp current from regular household lines, up to 16 amp of current if you happend to live around industrial sites, and if you where total nuts and used industrial main lines, then 25 amper was the maximum.
since the main's line could not offer any more.
keep in mind this build was never adwised, not many exsisted, and out of that not many most of them burned or exploded or done all kinds of funky stuff.
in exchange it was the cheapest way to get your dream amp of absolute power, rated maximum to single channel 5 Kw. fidelity was no question, who needs fidelity from an 5 Kw amp ?? you could weld with those without problems.
but keeping it not silly, probabaly the tda7293 BPA application circuit is what makes somewhat sense in class AB.
and for class D the trusty TDA8954 is your friend.
anything more.. i would adwise to not fiddle with it.
it can be verry lethal.
if we are allowed to go with unusal impedances as load, you can squeeeeeezeee out killowatts from class D amps and mosFets without issues.
the limitng factor is the output voltage of the chip, from then on mooar output devices will yield moooar powa.
in class AB it can be simular, but harder to do.
bridged and paralelled chips that have slave/master mode make things less problematic, however roughly 500 watt is the feasable design.
discerte designs while certainly harder, can offer anything you like.
one of the lunatic solutions of the end of the tube era used tubes for voltage gain, and the output devices where so silly that the unit featured NO trnformator. basicly it was able to throw whatever you main powerlines where able to provide.
s the output swing was 200 voltish, and if you lost your brain somewhere in theory it was able to spit 6 amp current from regular household lines, up to 16 amp of current if you happend to live around industrial sites, and if you where total nuts and used industrial main lines, then 25 amper was the maximum.
since the main's line could not offer any more.
keep in mind this build was never adwised, not many exsisted, and out of that not many most of them burned or exploded or done all kinds of funky stuff.
in exchange it was the cheapest way to get your dream amp of absolute power, rated maximum to single channel 5 Kw. fidelity was no question, who needs fidelity from an 5 Kw amp ?? you could weld with those without problems.
but keeping it not silly, probabaly the tda7293 BPA application circuit is what makes somewhat sense in class AB.
and for class D the trusty TDA8954 is your friend.
anything more.. i would adwise to not fiddle with it.
it can be verry lethal.
They are beyond my budget.
Linear - Amplifiers - Instrumentation, OP Amps, Buffer Amps | Integrated Circuits (ICs) | DigiKey
I haven't messed with one of these yet, but they look intriguing. They can run up to +/- 50 volts and have a provision for master/slave (parallel) hookup. They have DMOS output stage which means they will have no tendency towards thermal runaway.
Even if they suck, you could probably pump some serious watts into a 4 ohm subwoofer. Then you might be perfectly happy driving a high efficiency two-way with your 1875 amplifier. A 3886 "gainclone" driving full range speakers crossed at say 100 Hz with a 7293 parallel powerhouse driving a 4 ohm subwoofer ought to be plenty of clean power.
Check it out http://www.st.com/content/ccc/resou...df/jcr:content/translations/en.CD00001887.pdf You can still buy them from Digikey.
I messed around with one of the TDA chips (not this one) and got them to work. They're a little trickier than the 3886. They're known for blowing up if there's a loose solder connection or if wired improperly. I did fry one of mine (a quickie prototype) but no pyrotechnics.
Most chipamps are great with loads of 8ohms, or higher.
Most chipamps need some form of current, or power, limiting to drive loads lower than 4ohms.
Paralleling and/or lower supply voltages are two ways of reducing chipamp amp current to better suit lower load impedances.
Bridging is a way to force any chipamp into overheating because each chip in the bridged pair sees a halved load impedance.
If your brief requires high power and/or low load impedance, then chipamps are not the easiest way to get there.
Most chipamps need some form of current, or power, limiting to drive loads lower than 4ohms.
Paralleling and/or lower supply voltages are two ways of reducing chipamp amp current to better suit lower load impedances.
Bridging is a way to force any chipamp into overheating because each chip in the bridged pair sees a halved load impedance.
If your brief requires high power and/or low load impedance, then chipamps are not the easiest way to get there.
depends Andrew.
class D chips do pump a huge lump of current.
but they manage it with external components, not sure if its proper to mentin that setup here.
they are not pure 1 chip amps, but still not hard to get them to drive sub 1 ohm loads with full rails. it does not takes a lot to modify the schematics to get that.
class D chips do pump a huge lump of current.
but they manage it with external components, not sure if its proper to mentin that setup here.
they are not pure 1 chip amps, but still not hard to get them to drive sub 1 ohm loads with full rails. it does not takes a lot to modify the schematics to get that.
When you do some math dB vs watts it all seems to not matter much past 64 watts. Just my opinion but for another 3 dB after 64 watts I need 128 watts and that's just where the watt battle stops for me. At that point I look to more efficient speakers.
This site gives a great explanation well down the page
Loudness volume doubling sound level change factor of perceived loudness decibel scale log compare intensities formula calculate power level noise levels volume logarithm dependence three four fold loudness sound - by what factor does level decrease
On this site the author states "
A doubling of the sensed volume (loudness) is equivalent to a level change approximately between 6 dB and 10 dB." Man that takes a lot of watts. The cheapest way to get a loudness increase is to sit closer
This site gives a great explanation well down the page
Loudness volume doubling sound level change factor of perceived loudness decibel scale log compare intensities formula calculate power level noise levels volume logarithm dependence three four fold loudness sound - by what factor does level decrease
On this site the author states "
A doubling of the sensed volume (loudness) is equivalent to a level change approximately between 6 dB and 10 dB." Man that takes a lot of watts. The cheapest way to get a loudness increase is to sit closer
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Let me bounce this off of you guys and I might be way off base here so correct me if I am. I looked up the max that the positive DC rail can be for the top 3 contenders of the most powerful amps (not getting into bridge or parallel configurations).
If you figure a max rail to rail swing for the supply into the 4 ohm load with no losses and then look at max rated power, can you get a ballpark idea of efficiency or will it not even be close to real world measurements?
LM3886
42V -max supply -220.5W average power into 4 ohms @100% efficiency
?W in 4 ohms @10% THD 68W in 4 ohms @ 0.1% THD
~31% efficiency
TDA7293
50V -max supply -312.5W average power into 4 ohms @100% efficiency
100W in 4 ohms @10% THD
32% efficiency
TDA8954 Class D
42.5V -max supply -225.8W average power into 4 ohms @100% efficiency
210W in 4 ohms @10% THD
93% efficiency
Has anyone on DIY ever measured the TDA and LM against each other for max unclipped power?
If you figure a max rail to rail swing for the supply into the 4 ohm load with no losses and then look at max rated power, can you get a ballpark idea of efficiency or will it not even be close to real world measurements?
LM3886
42V -max supply -220.5W average power into 4 ohms @100% efficiency
?W in 4 ohms @10% THD 68W in 4 ohms @ 0.1% THD
~31% efficiency
TDA7293
50V -max supply -312.5W average power into 4 ohms @100% efficiency
100W in 4 ohms @10% THD
32% efficiency
TDA8954 Class D
42.5V -max supply -225.8W average power into 4 ohms @100% efficiency
210W in 4 ohms @10% THD
93% efficiency
Has anyone on DIY ever measured the TDA and LM against each other for max unclipped power?
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