Re: [Harp-L] Amp>DI box>PA

Greg Heumann <greg@xxxxxxxxxxx> · Mon, 4 May 2009 09:20:29 -0700

Yes, the DI box is at its heart just an impedance matching device.  
However some DI boxes are "active" meaning they can amply powered  
electronics to provide boost or cut functions. Some had "pad" switches  
to reduce signal by 10 or 20dB if the input is to high. Some have  
parallel inputs, allowing you (as suggested) to run a line to another  
amp. So DI boxes are sometimes have a few functions beyond impedance  
matching - but that is again the main function.

/Greg
http://www.blowsmeaway.com
http://www.bluestateband.net
From: Garry <harp@xxxxxxxxxxx>
Date: May 3, 2009 3:54:18 PM PDT
To: harp-l@xxxxxxxxxx
Subject: Re: [Harp-L] Amp>DI box>PA

Greg Heumann wrote:

The line-out on your amp is an unbalanced, high impedance signal.  
The purpose of the DI box is to change it to balanced, low  
impedance so that there is much less signal loss on the long run to  
the board.

does that imply that he could have accomplished the same thing with an
inline impedance transformer, like many use on their mic cables?