[LAU] OT: Phantom power and my acoustic guitar

[andy baxter]

Andrea Del Signore wrote:
> Hi all,
>
> sorry for the off-topic post, but since I'm a linux audio user from a
> long time
> this is the only audio group that I know ;)
>
> My question is: can I connect an Ibanez AW40ECE-NT guitar to a mixer
> with
> phantom power switched on? The guitar has a fishman pickup and an Ibanez
> SST
> preamp and I'll connect with the mixer using the XLR output, so the
> connection
> will be XLR to XLR.
>   

I was wondering whether it would be possible to remove the phantom power 
DC voltage with a fairly simple circuit rather than having to buy 
another preamp? This is really a question to others on the list who know 
more than I do about electronics, rather than advice. My thought was 
that all you need is an RC high pass filter, set at a frequency of maybe 
1Hz or less, plus some kind of voltage limiting device to remove the 
positive and negative going pulses that would occur when you first 
connected or disconnected the circuit (a couple of zener diodes back to 
back in series?)

What I'm saying is it might be possible to build a circuit with only a 
few components which would remove the DC phantom power coming out of the 
mixer and still allow the higher frequency audio signal from the guitar 
to get through.

As I said though, I'm not confident enough with electronics to come up 
with a design that I would trust to work on somebody else's (presumably 
expensive) guitar, just wondering out of interest if this would work in 
principle.

andy


P.S. Having written this, I thought I'd check if something like this 
exists already. I found these two pages:

http://www.blue-room.org.uk/wiki/Splitters
http://www.blue-room.org.uk/wiki/Phantom_Power

which suggest that you can remove phantom power from a cable using 
something called a transformer splitter.