Differential Reverb (better subject line!)

[honcho at paia.com]

Don Tillman writes:

>A couple of friendly suggestions for this circuit:

>Invert the receive transducers instead of the send transducers; hum
>cancelling for free!

>Accutronics recommends using lots of drive current; more than an 
>opamp could provide.  Their application note has half-a-dozen drive
>circuits.
>>>

Really good suggestions, Don, thanks. But remember that the 
transducers are in two tanks and not particularly close together so 
that hum rejection _might_ not be that great. There's not much reason 
to expect that the transducers in each tank will have the same 
exposure to flux because of their physical separation - it still would 
be wise to keep tanks away from magnetic fields from transformers and 
such in the first place.

Better drivers might be better, but several folks have pointed out 
already that the Hot Springs is a pretty incredible little reverb and 
who's to say that some of the magic doesn't come from the driving 
properties of the op-amps :-)

-John

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John Simonton                  PAiA Electronics, Inc
3200 Teakwood Ln.              honcho at paia.com
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