User`s guide

Typical Output Stage [O]
C2 - C5
o----||----o
| R3 - R6 |
trim pot o--/\/\/\--o
o----o | _ |
| v | | \_ |
----o--/\/\/\--o-|- \_ |
R7 - R10 | \__o---------
o-|+ _/
| | _/
| |_/ 1/2 IC3 - IC4
_|_
///
R1 - R6 : 1.2k ohm
R7 - R10 : 2k ohm trim potentiometer
C1 - C5 : 47pf
IC1 : LM318 high speed op-amp
IC2 : 74F139N dual 2 to 4 decoder
IC3 - IC4 : TL072 dual op-amp jfet input
IC5 - IC6 : 4016 cmos SPST analog switch
IC7 : 4069 cmos hex inverter
______________________________
From: Brian Willoughby
While there is nothing *wrong* with your circuit, I thought that I would
mention that the functionality of IC2, IC5, 6 & IC7 are combined in a few
standard CMOS chips. It turns out that your circuit is so useful in many
applications that you can easily find it in one chip, thus saving wiring and
lowering noise.
Look for a Siliconix DG506 or any make of 4058. I'm not absolutely sure
about the number 4058, but just check in any CMOS 4000 series list for an 8-
channel to 1 analog multiplexer/demultiplexer (not the digital type, they won't
handle audio/sound signals).
______________________________
From: Seth D. Kadesh
One of the chips Brian refers to is a 4052. Both the LM318 and the 4052 can be
purchased from B.G. Micro (214-271-5546). Cost for both was $3.75 USA.
The other parts can be purchased from Radio Shack.