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Re: Electro Harmonix Freeze - Sound Retainer

>Charles Zwicky wrote:
>>  A reverb is not simply a "network of delays",
>...but your description below is *exactly* that.
>All the elements of it are composed of delays.

Perhaps to the uninformed it would appear that way... so when is a 
"delay" not a delay?

When it's used to create an allpass.

The delays used in an allpass filter are typically very  short, and 
measured in samples rather than mS...

>I didn't hear increasing phase dispersion in the EH examples,
>which would be the case if the sound was looping through an allpass, 
>but maybe I just didn't hear it.

I'm not sure that you meant to write "phase dispersion"... Try to 
think about the topolgy in a different way.   If the allpass network 
is located after the loop, it would diffuse the signal but not cause 
an increase in density with each repeat, as would be the case if the 
AP filter were inside the loop.  This would also obscure the loop 
points if there were enough AP filters in series.

>>in fact most digital reverbs consist of  a loop of allpass filters* 
>>set to various delay lengths with a variety of injection points and 
>>output taps.
>>* An allpass filter is defined as a feedforward  delay combined 
>>with a feedback delay, it is at the heart of every digital reverb 
>>and the result of increasing the coefficient is greater diffusion.