B&O icepower 500A modules: need output LC?

[packman]

I have an implementation with 2 of these modules and there is a LC filter outboard, is this filter an extra or the icepower needs that filters because don't have them onboard?
Thanks

 

[theAnonymous1]

There is a 2nd order filter and zobel network on the module. Are you sure the outboard filter is connected to the outputs and not some kind of power filter?

http://www.icepower.bang-olufsen.com/files/solutions/icepower500adata.pdf

 

[packman]

yes

Yes theA i'm sure.
it's not simple to see the scheme but it's a small circuit from the output of the 2 icepower to the speakers connections.
It has some caps and 2 toroidal L

 

[bwaslo]

It must be some kind of extra filter to remove switching frequencies or RF noise. Probably not a good idea for the audio performance, though, since that filter would be outside the feedback loop (having feedback that included the filter was supposed to be a big advantage of ICEpower, though not as thorough as the UcD design in that respect).

 

[packman]

highs rolloff

that's interesting bwaslo, the sound is excellent and fluid but i hear a rolloff of the high frequencies so want to try to reduce that effect bypassing the lowpass filters around the icepower (but without any risks of damage the modules).
The load isn't very easy to drive (B&W 801 Matrix II), can i try to connect them directly to the icepowers?

 

[bwaslo]

I don't see why not. Provided the original filters are still within the ICEpower modules.

Of course, they aren't my speakers that would be getting hooked up...you have to estimate the risk yourself. Maybe connect to some cheap speakers first, to make sure before connecting the B&Ws.

What is the amplifier? Is it a commercial amp assembly with that filter added, or something cobbled by a DIYer?

If a commercial amp, it might be something they had to add to meet FCC or CE radio non-interference requirements.

 

[packman]

Hi, it's a commercial amp.
I think the FCC or CE requirements can be the real reasons of that filters, like you said.
Sure i always tried modded amps with cheap car speakers first
The B&W have a bypass in the protection circuits so need attention.