What's the relation between input and output power of the TPA3255?
https://www.ti.com/product/TPA3255
I'm a beginner...
I don't understand this table Fosi Audio V3 mono:
Why can it output so much more with higher voltage?
PSU 32x5=160W and 48x5=240W, so factor 1.5
But at 4Ohm (rated), factor 2.4
I'm using two 36V/6A PS, I thought that might make it heat up less (less stress). Am I wrong?
https://www.ti.com/product/TPA3255
I'm a beginner...
I don't understand this table Fosi Audio V3 mono:
Why can it output so much more with higher voltage?
PSU 32x5=160W and 48x5=240W, so factor 1.5
But at 4Ohm (rated), factor 2.4
I'm using two 36V/6A PS, I thought that might make it heat up less (less stress). Am I wrong?
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For an amp, the input (signal, not power supply) power is negligible. The power drawn from the PSU depends on the output level and load impedance.
With a higher supply voltage more power can be supplied to the load but you'll still need a higher signal level - a higher setting on your volume control - to allow that extra power through.
Two power supplies when the design only needs one?
With a higher supply voltage more power can be supplied to the load but you'll still need a higher signal level - a higher setting on your volume control - to allow that extra power through.
Two power supplies when the design only needs one?
Sorry, I'll write it another way... Why does 1.5x the PS voltage (32/48V) allow up to 2.4x the output (100/240W). Does the TPA3255 have a favorite voltage... "nonlinear ratio in to max out"?
Of course I expect the amp to offer let's say 50W@4Ohm regardless of the PS used. But will it get less hot doing so with a lower voltage PS? Like underclocking a cpu?
Sorry for the "two PS" confusion. The default V3M set you can order (and I got used) is with 1x 48V/10A PS + splitter for both amps. I changed to dedicated PS later.
Of course I expect the amp to offer let's say 50W@4Ohm regardless of the PS used. But will it get less hot doing so with a lower voltage PS? Like underclocking a cpu?
Sorry for the "two PS" confusion. The default V3M set you can order (and I got used) is with 1x 48V/10A PS + splitter for both amps. I changed to dedicated PS later.
1.5X the PS voltage in theory gives 1.5X1.5 = 2.25X the power because for a fixed impedance the power is proportional to the square of the voltage. So yes the relationship volts-to-power is non-linear.
Any amp will get loss hot running on a lower supply as all amps have a quiescent current - the current drawn in absence of any signal. So choose your supply voltage to suit your requirement for max output power. It is rather like underclocking a CPU - choose a clock frequency sufficient to accomplish your heaviest anticipated load and no more.
Any amp will get loss hot running on a lower supply as all amps have a quiescent current - the current drawn in absence of any signal. So choose your supply voltage to suit your requirement for max output power. It is rather like underclocking a CPU - choose a clock frequency sufficient to accomplish your heaviest anticipated load and no more.
Yes, this is better for reliability , less heat than using 48V for the Fosi audio v3 mono.
Using two 36V 6A supply’s is about the same as using one 36V 12A with a split cable.
Mono coupled power supplies will also sound better in most cases.
The tpa3255 chip has the lowest distortion at 34 V .
This is the real power output from Fosi v3 mono using a 48V 5A for each amplifier:
This is a bit less than the stated 240W.
Using two 36V 6A supply’s, there will be only a small difference using 4 ohm speakers and the reliability will be better .
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Which voltage is best depends on how you use such an amp. If you use it only for low volume background music, even something like 24 Volt may be OK. If you use it in a Home Cinema, going near to the 50 Volt limit will keep the headroom high. Less voltage means less headroom, this is a fact.
The little bit of extra heat produced from higher voltage during idle will not change the life expectancy in any relevant manner, even as the amp may feel a bit warmer.
The current demand of the amp is something more complicated. The usual power supply may have some tollerance to higher than rated current output, it also may have less than rated and sometimes go into protection for a second.
In normal operation the "usual" D-amp will not need more input than it is forced to give at the output. Which may sound a little bit paradox, but music is not DC nor sine waves. Power supply as well as the amp board store energy in capacitors. This will fill the gap during high demand and instandly recharge. A 48 Volt/ 10 Amps supply should drive a stereo 3255 in almost any case. If you use the Mono 3255 with a two Ohm load to the limit, you should use the same 10A supply, but the small cases without external heat sink should not be used to drive 2 Ohm subs at full power. Maybe use another kind of amp for this task, having more surface to spread the excessive heat. Even a D-amp will have losses of 10-30% depending on the kind of use. For exact numbers look into the data sheet.
One thing last, all these small D-amps with high output have no thermal reserve for permanent high power at the edge of what the chip can deliver. They are build like a car engine that will overheat when driven at full speed, because the designer decided no one is going to drive it that hard anyway.
The little bit of extra heat produced from higher voltage during idle will not change the life expectancy in any relevant manner, even as the amp may feel a bit warmer.
The current demand of the amp is something more complicated. The usual power supply may have some tollerance to higher than rated current output, it also may have less than rated and sometimes go into protection for a second.
In normal operation the "usual" D-amp will not need more input than it is forced to give at the output. Which may sound a little bit paradox, but music is not DC nor sine waves. Power supply as well as the amp board store energy in capacitors. This will fill the gap during high demand and instandly recharge. A 48 Volt/ 10 Amps supply should drive a stereo 3255 in almost any case. If you use the Mono 3255 with a two Ohm load to the limit, you should use the same 10A supply, but the small cases without external heat sink should not be used to drive 2 Ohm subs at full power. Maybe use another kind of amp for this task, having more surface to spread the excessive heat. Even a D-amp will have losses of 10-30% depending on the kind of use. For exact numbers look into the data sheet.
One thing last, all these small D-amps with high output have no thermal reserve for permanent high power at the edge of what the chip can deliver. They are build like a car engine that will overheat when driven at full speed, because the designer decided no one is going to drive it that hard anyway.