Audio Research and Power Supply

[nonesup]

Hi.
There is something that intrigues me for some time. When you read the technical characteristics of the majority of the amplifiers in the amount of the power supply section, indicate the microfarads of filter capacitors and Volts x Amps, of the transformer. However AR gives a value in joules (energy), and do not know how to interpret it.
thanks

[Barry1]

Try this: Electronics 2000 | Capacitor Charge / Energy Calculator for the caps. It takes both the voltage and the capacitance into account and is the measure of energy produced.

[TOGA]

I think Audio Research is right. Joules is the actual energy.
There is no need to interpret further unlike capacitance.
Toga

[nonesup]

Originally Posted by Barry1

Try this: Electronics 2000 | Capacitor Charge / Energy Calculator for the caps. It takes both the voltage and the capacitance into account and is the measure of energy produced.

Thanks Barry1
Very interesting page. But to calculate microfarads my AR Ref 110
would have to know the value in volts of the output current of the transformer.
Know which is the voltage?

[nonesup]

Originally Posted by TOGA

I think Audio Research is right. Joules is the actual energy.
There is no need to interpret further unlike capacitance.
Toga

Hi Toga.
What I want is to have a method to compare power supply when the data given in these two different formats joules or microfarad

[Barry1]

Exact formula is: W = 1/2 C X V2 where:

W = energy stored (Joules)
C = capacitance (Farad)
V = Power supply (Voltage)

I don't know the voltage of Ref110 but you can work backward if ARC provides the joules in their literature and you can count the microfarad values on all the capacitors. Also, read the voltage value on the side of PS capacitors. That value is 20-30% higher than the actual voltage in the power supply (for safety).

[TOGA]

Originally Posted by nonesup

Hi Toga. What I want is to have a method to compare power supply when the data given in these two different formats joules or microfarad

Yes right, convert to Joules and.. Make it as "per channel" too. Toga

[nonesup]

Originally Posted by Barry1

Exact formula is: W = 1/2 C X V2 where:

W = energy stored (Joules)
C = capacitance (Farad)
V = Power supply (Voltage)

I don't know the voltage of Ref110 but you can work backward if ARC provides the joules in their literature and you can count the microfarad values on all the capacitors. Also, read the voltage value on the side of PS capacitors. That value is 20-30% higher than the actual voltage in the power supply (for safety).

Hi.
I have looked inside the Ref 110 and there are 12 capacitors, indicating 450v / / 470 microfarads.
This means that the overall filtering capacity is 470 x 12 = 5640 microfarads?
I say this because it seems a very low figure compared to other solid state amp.

[MPS]

Originally Posted by nonesup

Hi.
I have looked inside the Ref 110 and there are 12 capacitors, indicating 450v / / 470 microfarads.
This means that the overall filtering capacity is 470 x 12 = 5640 microfarads?
I say this because it seems a very low figure compared to other solid state amp.

Capacitance is relative to current. You can rather compare those values or energy capacity stored in capacitance.

[Barry1]

Nones up: It appears low, but that's ok. Look at the formula again. PS rail voltage for a typical 200watt per channel solid state @ 8 ohms amplifier is only about 70-80 volts. The ARC supply has 6times the voltage and that value is squared when calculating the energy storage. It doesn't need the same amount of capacitance as a solid state supply to produce equivalent amounts of energy because the voltage is so much higher.