Hi Dwayne.

Good observation indeed :) ( +V1 -V2 to GND compared to +Vcc to GND )
Ground is only reference, no headaches with pseudo-ground offsets
( and especially with caps recharging when circuit powers up :)

Big minus is - one has to create negative supply voltage
( which is doable with plenty to select from voltage inverting chips )

Bonus - available input/output voltage range is doubled
( since supply is +V to -V instead of +V to GND )


Question 2 All: How someone would mute the circuit without causing pops ?
I.e. muting circuit has to be simple, be able to "smoothly" cut off input
signal even when it is at maximum amplitude in the moment when muting
is happening. Digital pots are excluded from competition :)

Any ideas ?


WBR Dmitry.



Dwayne Reid wrote:
> 
> At 03:50 PM 12/12/2005, talgo wrote:
> >Hi All
> >
> >I asked few month ago about the 4066 bilateral switch and i lost
> >your answers, and I'm confuse again.
> >
> >I want to distribute 6 different audio lines to 3 different
> >equipment. my problem is, when one equipment is connected i can hear
> >the signal (very low but can hear it)  in the other two outputs even
> >they are disconnected by the 4066 switches. some of you suggest to
> >ground temporarily the unused output when not using them.
> 
> Are you stuck with using the 4066?  Can you use a 4053 instead of 4066?
> 
> Two major reasons for using 4053 instead of 4066:
> 
> 1) the switches are SPDT.  Connect the incoming signal to the
> Normally OPEN contact, take the output from the armature (common)
> terminal, connect the Normally CLOSED contact to ground.
> 
> 2) the 405x family (4051, 5052, 4053) allow powering the switch
> section of the IC from both positive & negative supplies.  You can
> use +5V & -5V but I normally use plus & minus 7.5V.  Note that the
> logic signals swing between ground and positive rail.
> 
> Each 4053 chip contains 3 separate SPDT switches - you would need 2
> chips to switch 6 audio lines as you described.
> 
> Hope this helps!
> 
> dwayne
> 
> --
> Dwayne Reid   <dwayner@planet.eon.net>
> Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
> (780) 489-3199 voice          (780) 487-6397 fax
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