What does this choke do?

[Axtman]

Almost all of the Peavey amps I work on have this choke to the speakers. What does it do and how can I test it?

[mikeydee77]

Anti oscillation zobel network i believe. Usually a cap to ground and resistor but prob same idea.

[Helmholtz]

A low inductance serial choke attenuates RF frequencies.
If within the global NFB loop it's used for amp stability.
If not, it's there for EMI purposes.

DCR should be close to zero.

[The Dude]

I'll add: It's not just in Peavey amps. Most all solid state amps have a choke and usually a complete zobel network at the output.

[Helmholtz]

Please post complete schematic.

From your snippet it looks as if the choke is outside the NFB loop.
If so, it can't have an influence on amp stability like a Zobel (always being inside the NFB loop).

[Greg Robinson]

Protects output devices from cable and speaker capacitance by increasing impedance at high frequencies so if for any reason the amp breaks out into HF oscillation, they're not running into a short. Also important for stability as Helmholtz and others mention.

[Axtman]

Here is the schematic:

[Helmholtz]

Anybody know what the "booster" output/terminal is for?

[Axtman]

I think the "Booster" is used for a slave amp.