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I commented about output power of 1ET400A and 1ET7040SA. And I could see some misleadings and errors. So i decided to start this thread.
Let's check 1ET400A first.
The current limit for the 1et400 is 25 A.
Not 15 A as one of our member boXem claims.
It is clearly stated in the data sheet.
You can cross check, My 2 Ohms 580 Watts output measure of 1ET400A based Amplifier is entirely consistent with a 25 A peak current limit in the data sheet.
P(W, Watts)
V(V, Volts)
I(A, Amps, Amperes)
R(Ω, Ohms)
P = V x I = I^2 x R
Sqrt (P/R) = I
I measured 1ET400A pushed 580W, 2 Ohms @ 1%
Sqrt (580 W / 2 Ohms ) = 17 A rms ( or 24 A peak)
24 A peak is definitely below 25 A Datasheet claims.
So, we can clearly see current limiting(so-called OCP) didn't engaged, PSU fed 1ET400A power well, do not limited any performance of Amplifier.
With 1ET400A and appropriate Power Supply Units, The only limitation factor is Heat that detected by sensors of Purifi units, which is depends on Physical Thermal capacity of complete Amplifier, unless hit OCP engages @ 25 A.
With this graph, one of our member claimed 1ET400A's limits are 450 W @ 2 Ohms / 15 A of current.
Quite often the Company like Purifi need to write strict numbers in their spec-sheet like 450 W. But, they brightly printed letters ~ 25 A on the first page of sheet as you saw.
Further more, you can see another page of sheet.
This means at least about 450 W Output powers are expected with right PSU.
So, Estimate limit current '15 A' from number '450' is completely misread of data.
Especially, company owners are responsible to provide correct information about their own products. Wrong informations must correct immediately at the moment Company recognised.
Claiming "15 A is the point OCP engages" as someone from Internet and Claiming "15 A is the point 1ET400A's OCP engages" as Company owner is completely different game.
Most of limits of Purifi-based Amplifiers are determined by how it is designed and implemented.
Like,
How to feed the signal to Purifi unit
How to feed the power to Purifi unit
How to cool the Purifi unit
Then, Let's see 1ET7040SA.
This is the same graph in the 1ET7040SA datasheet. The graph indicates PSU of Arthur 4222/E1 Amplifier is running at about 61 volts (700 W @ 2 Ohms) instead of the 1ET7040SA's originally rated 70 volts (to produce 950 W @ 2 Ohms).
It also mean 61 V PSU will get way higher THD+N at same output power like 700W than 70 V PSU.
(THD+N : the lower the better)
Compare to well powered 1ET400A(580 W)
700 W Arthur 4222/E1 is near to 1ET400A(120 W less than 700 W) instead of 1ET7040SA's rated power(250 W more than 700 W).
And 1ET400A has better SINAD than 1ET7040SA.
So, If you decide to use 1ET7040SA, it is better to set it to sufficient power to get enough gain not marginal.
If you decide to build of get Purifi-based amplifiers, Do you want to limit the performance with PSU or Amplifier Unit itself?
Still Arthur 4222/E1 Amplifier is nice Amp at absolute scale. Most of Amplifiers on the market has worse performance than Arthur 4222/E1 Amplifier.
But as Point of view of Purifi-based applications, That's much less than Purifi Units own capabilities. Arthur 4222/E1 Amplifier could do better with little more efforts.
1ET7040SA can do more, so 1ET7040SA based Amplifier could do more, too.
That is why the name 7040 is 7040.
70 V , 40 A
This is my point of view.
Let's check 1ET400A first.
The current limit for the 1et400 is 25 A.
Not 15 A as one of our member boXem claims.
It is clearly stated in the data sheet.
You can cross check, My 2 Ohms 580 Watts output measure of 1ET400A based Amplifier is entirely consistent with a 25 A peak current limit in the data sheet.
P(W, Watts)
V(V, Volts)
I(A, Amps, Amperes)
R(Ω, Ohms)
P = V x I = I^2 x R
Sqrt (P/R) = I
I measured 1ET400A pushed 580W, 2 Ohms @ 1%
Sqrt (580 W / 2 Ohms ) = 17 A rms ( or 24 A peak)
24 A peak is definitely below 25 A Datasheet claims.
So, we can clearly see current limiting(so-called OCP) didn't engaged, PSU fed 1ET400A power well, do not limited any performance of Amplifier.
With 1ET400A and appropriate Power Supply Units, The only limitation factor is Heat that detected by sensors of Purifi units, which is depends on Physical Thermal capacity of complete Amplifier, unless hit OCP engages @ 25 A.
With this graph, one of our member claimed 1ET400A's limits are 450 W @ 2 Ohms / 15 A of current.
Quite often the Company like Purifi need to write strict numbers in their spec-sheet like 450 W. But, they brightly printed letters ~ 25 A on the first page of sheet as you saw.
Further more, you can see another page of sheet.
This means at least about 450 W Output powers are expected with right PSU.
So, Estimate limit current '15 A' from number '450' is completely misread of data.
Especially, company owners are responsible to provide correct information about their own products. Wrong informations must correct immediately at the moment Company recognised.
Claiming "15 A is the point OCP engages" as someone from Internet and Claiming "15 A is the point 1ET400A's OCP engages" as Company owner is completely different game.
Most of limits of Purifi-based Amplifiers are determined by how it is designed and implemented.
Like,
How to feed the signal to Purifi unit
How to feed the power to Purifi unit
How to cool the Purifi unit
Then, Let's see 1ET7040SA.
This is the same graph in the 1ET7040SA datasheet. The graph indicates PSU of Arthur 4222/E1 Amplifier is running at about 61 volts (700 W @ 2 Ohms) instead of the 1ET7040SA's originally rated 70 volts (to produce 950 W @ 2 Ohms).
It also mean 61 V PSU will get way higher THD+N at same output power like 700W than 70 V PSU.
(THD+N : the lower the better)
Compare to well powered 1ET400A(580 W)
700 W Arthur 4222/E1 is near to 1ET400A(120 W less than 700 W) instead of 1ET7040SA's rated power(250 W more than 700 W).
And 1ET400A has better SINAD than 1ET7040SA.
So, If you decide to use 1ET7040SA, it is better to set it to sufficient power to get enough gain not marginal.
If you decide to build of get Purifi-based amplifiers, Do you want to limit the performance with PSU or Amplifier Unit itself?
Still Arthur 4222/E1 Amplifier is nice Amp at absolute scale. Most of Amplifiers on the market has worse performance than Arthur 4222/E1 Amplifier.
But as Point of view of Purifi-based applications, That's much less than Purifi Units own capabilities. Arthur 4222/E1 Amplifier could do better with little more efforts.
1ET7040SA can do more, so 1ET7040SA based Amplifier could do more, too.
That is why the name 7040 is 7040.
70 V , 40 A
This is my point of view.
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