Understanding Anthem Amp2 output circuit

[ronenash]

Hi all,

I need you assistance with understanding the output circuit in my Anthem amp2 which I am upgrading now. Just prior to the output to the speaker terminals there is an inductor and resistor in paralel with a capacitor to ground. It looks like some kind of filter which I guess can be removed to improve the sound of the amp. I have attached a snip of the schematic.

Can you please assist me in understanding the purpose of this circuit and if I can safely rmove it?

Regards
ronenash

[llwhtt]

Search "Zobel network" to find your answer. Almost all solid state amplifiers use these networks, the resistor/capacitor combo from output to ground is probably used on 99% of solid state amplifiers. I would NOT remove them.

Craig

[ronenash]

I tried to search Zobel Network but can't fully understand what their purpose is.

[nigelwright7557]

Originally Posted by ronenash

I tried to search Zobel Network but can't fully understand what their purpose is.

The zobel network is there to counteract some of the inductance in the speaker.

The inductor decouples the amp output a little from the speaker.
This makes the amp less likely to oscilate.

[tiefbassuebertr]

Originally Posted by ronenash

Hi all,

I need you assistance with understanding the output circuit in my Anthem amp2 which I am upgrading now. Just prior to the output to the speaker terminals there is an inductor and resistor in paralel with a capacitor to ground. It looks like some kind of filter which I guess can be removed to improve the sound of the amp. I have attached a snip of the schematic.

Can you please assist me in understanding the purpose of this circuit and if I can safely rmove it?

Regards
ronenash

This output circuit is to find by most amp models and not only in your Anthem amp2. The google keyword for the parralel network consist by a resistor and capacitor is so called "boucherot cell" (or "Zobel network") This ensures a basic load to higher frequencies. Actually a impedance input linearization of your speaker crossover high pass.

here examples:
Boucherot cell (Zobel network) values
Boucherot cell - Wikipedia, the free encyclopedia
IC Audio Power Amplifiers and Zobel Networks: One Size Does Not Fit All | Digital Home DesignLine
try also search by Images with this terms

The google keyword for the serial network consist by a coil and a parallel resistor I don't know. This ensures a protection, if you use speakers, that have nearly shorting character in direction of higher frequencies (i. e. 0,1 ohms above 10 KHz). Mostly to observe by planar speakers like ribbon without matching transformer.

[unclejed613]

the inductor isolates capacitve loads from the amplifier output, the parallel resistor dampens the inductance. the other part of the Zobel network, the cap and resistor, shunt high frequency components of the signal to ground, reducing the tendency for oscillation. DO NOT remove these components, your amp could become an RF power oscillator and self destruct as a result.