Hi All...
I do hope it's in the right thread I'm posting
The Crescendo with 4 output transistors VS Crescendo with 8 output transistors respectfully 140w VS 250w, how is the difference possible ?
Would som one help me figure out the calculation on the output on Crescendo 140W@8Ω and The 250W@8Ω
I struggle to see how it is calculated.
Both amps has a power supply at ±75Vdc how can there be a difference when the load is 8Ω.
I am well aware that the 250W has 8 output transistors compared with the 140W that has 4 output transistors
The biggest difference is the R31 1Ω parallel with Coil @ 2µH in the 140W version witch is not present in the 250W version.
Both amps has losses in the drain resistor @ 0.22Ω however the losses in the 250w version is almost not existent since the resistor is in parallel so 2x 4//0.22 in parallel compared to 2x 2//0.22Ω.
However this doesn't justifies the huge difference in the output.
In reality both amps are looking in to the same load, no matter if it is in AC orr DC perspective
So the big question is why is one amp rated to 140 W and the other 250 W and both are measured in 8Ω ?
Best Regards Allan
I do hope it's in the right thread I'm posting
The Crescendo with 4 output transistors VS Crescendo with 8 output transistors respectfully 140w VS 250w, how is the difference possible ?
Would som one help me figure out the calculation on the output on Crescendo 140W@8Ω and The 250W@8Ω
I struggle to see how it is calculated.
Both amps has a power supply at ±75Vdc how can there be a difference when the load is 8Ω.
I am well aware that the 250W has 8 output transistors compared with the 140W that has 4 output transistors
The biggest difference is the R31 1Ω parallel with Coil @ 2µH in the 140W version witch is not present in the 250W version.
Both amps has losses in the drain resistor @ 0.22Ω however the losses in the 250w version is almost not existent since the resistor is in parallel so 2x 4//0.22 in parallel compared to 2x 2//0.22Ω.
However this doesn't justifies the huge difference in the output.
In reality both amps are looking in to the same load, no matter if it is in AC orr DC perspective
So the big question is why is one amp rated to 140 W and the other 250 W and both are measured in 8Ω ?
Best Regards Allan
It appears the high output version uses two transformers rather than one, so more current is available....
Hi Andersonix
Thanks for joining.
I hope I eventually will find out what's causing this issue.
Indeed the power supply is dubbed size, and it has double output Fets however the load is still 8 Ohm.
How can it have more effekt ?
As I see it, when you have the same output voltage and tha same load, no matter that it is inductive or purely ohmic doesn't change anything.
The output effect will always be the same.
It is not even possible If they designed the 140 W amp with the weak transformer.
First of all it would had sound dreadful, secondly, the transformer have to be almost 50% smaller, it is just not possible.
I have built both amp's back in the late 1980 the 140 W and the 250W, both amp's sound very nice.
The biggest difference is the 140 W gets warm and the 250 W stays cold.
Allan
Thanks for joining.
I hope I eventually will find out what's causing this issue.
Indeed the power supply is dubbed size, and it has double output Fets however the load is still 8 Ohm.
How can it have more effekt ?
As I see it, when you have the same output voltage and tha same load, no matter that it is inductive or purely ohmic doesn't change anything.
The output effect will always be the same.
It is not even possible If they designed the 140 W amp with the weak transformer.
First of all it would had sound dreadful, secondly, the transformer have to be almost 50% smaller, it is just not possible.
I have built both amp's back in the late 1980 the 140 W and the 250W, both amp's sound very nice.
The biggest difference is the 140 W gets warm and the 250 W stays cold.
Allan