Paia 9710 Guide

9710 VCA 1
000216
Model 9710
Assembly and Using Manual
Triple VCA w/Modulator
(c) 2000 PAiA Electronics, Inc.
Ordinarily, Voltage Controlled Amplifiers are pretty
routine. But by combining 2 VCAs, a Balanced
Modulator, a White Noise Source and Envelope
Generator in a single module and interconnecting
them with a powerful normalization design, the 9710
redefines what a VCA module should be.
At the highest level, you can use the 9710 like a
traditional VCA but with the added convenience of a
built-in Voltage Controlled Input Submixer and ADSR
Envelope Generator. This configuration of elements
allows a couple of signals to be mixed together
before being processed by the VCA which is con-
trolled by the ADSR. It would ordinarily require three
or four modules and a handful of patch cords but is
embodied as a single element in the 9710.
And the versatility of individual modules is not
sacrificed because patch cords can be used to
override the normalization and access progressively
lower level functional sub-groups or even the indi-
vidual elements.

2 9710 VCA 000216
ASSEMBLING THE 9710 Triple VCA W/Modulator
Before beginning assembly, go through the manual.
Look at the drawings. Feel the parts. You’re
naturally eager to plunge right in, but take a few
deep breaths first. Check the parts supplied against
the packing list on the last page of this manual.
In some cases, notes packed with the parts will
be used to call your attention to special situations.
These notes may be in the yellow "MISSING PARTS"
postcard. If parts are missing please notify PAiA at
p405.340.6300, f340.6378, or [email protected] .
Notice that each step in the manual is marked with
a checkoff box like this:
DESIGNATION VALUE COLOR CODE
( ) R27 100 ohm brown-black-brown
Checking off each step as you do it may seem
silly and ritualistic, but it greatly decreases the
chance of omitting a step and also provides
some gratification and reward as each step is
completed.
Numbered figures are printed in the Illustrations
Supplement in the center of this manual. These pages
may be removed for easy reference during assembly.
THE CIRCUIT BOARD
The 9710 VCA is built on a double-sided circuit
board. No special preparation or cleaning is necessary
before assembly. The "top" of the board is the side that
is printed with component designations and parts are
mounted from this side. The "bottom" of the board is
also called the solder side and is masked with a
conformal coating to lessen the chance of solder bridges.
Solder pads are tin-lead plated for ease of soldering and
assembly.
TOOLS
You’ll need a minimum of tools to assemble the kit
- a small pair of diagonal wire cutters and pliers,
screwdriver, sharp knife, ruler, soldering iron and

9710 VCA 3
000216
solder.
Modern electronic components are small (in case you
hadn’t noticed) and values marked on the part are
often difficult to see. Another handy tool for
your bench will be a good magnifying glass. Also
use the magnifier to examine each solder joint as
it is made to make sure that it doesn’t have any of
the problems described in the SOLDERING section
which follows.
SOLDERING
Select a soldering iron with a small tip and a
power rating not more than 35 watts. Soldering
guns are completely unacceptable for assembling
solid state equipment because the large magnetic
field they generate can damage components.
Use only a high quality 60/40 alloy rosin core solder
(acid core solder is for plumbing, and silver solder is
for jewelry - neither is for electronics work). A proper solder
joint has just enough solder to cover the soldering
pad and about 1/16-inch of lead passing through it.
There are two improper connections to beware of:
Using too little solder will sometimes result in a
connection which appears to be soldered when
actually there is a layer of flux insulating the
component lead from the solder bead. This
situation can be cured by reheating the joint and
applying more solder.
Too much solder may produce a conducting bridge of
excess solder between adjacent pads causing a
short circuit. If WAY too much solder is used it may flow
through the hole and cause bridges between conductors
on the component side of the board or even impede the
action of mechanical components such as trimmer
potentiometers. Accidental bridges can be cleaned off by
holding the board upside down and flowing the excess
solder off onto a clean, hot soldering iron.
Use care when mounting all components. Never force
a component into place.
Special thanks to the
beta crew -
Scott Lee
Tim Furry
Johnny Klonaris
David Hillel Wilson
and me - John Simonton

4 9710 VCA 000216
Resistors
Solder each resistor in place following the parts placement
designators printed on the circuit board and the
assembly drawing fig 1. Note that resistors are nonpolarized
and may be mounted with either lead in either of the holes
in the board. Before mounting each resistor, bend its leads
so that they are at a right angle to the body of the part. Put
the leads through the holes and then push the resistor firmly
into place. Cinch the resistor in place by bending the leads
on the solder side of the board out to an angle of about
45 degrees. Solder both ends of each resistor in place
as you install it. Clip each lead flush with the solder joint
and save a few of the clippings for use in later steps.
A tip: If you can't find the location for a resistor, go on to the
next one and come back. DO NOT CHECK OFF A PART
UNTIL IT IS INSTALLED AND SOLDERED.
DESIGNATION VALUE COLOR CODE A-B-C
listed below: 100 brown-black-brown
( ) R28 ( ) R33 ( ) R40 ( ) R44
listed below: 100k brown-black-yellow
( ) R4 ( ) R5 ( ) R8 ( ) R9
( ) R11 ( ) R14 ( ) R65 ( ) R67
( ) R73 ( ) R89 ( ) R92 ( ) R94
( ) R96 ( ) R105
listed below: 10k brown-black-orange
( )R12 ( ) R13 ( ) R21 ( ) R50
( ) R64 ( ) R66 ( ) R91 ( ) R93
( ) R95 ( ) R100 ( ) R102 ( ) R104
( ) R108 ( ) R118
( ) R38 10m brown-black-blue
( ) R48 10m brown-black-blue
listed below: 120k brown-red-yellow
( ) R3 ( ) R6 ( ) R7 ( ) R10
( ) R19 ( ) R76
( ) R15 1500 brown-green-red
( ) R18 1500 brown-green-red
( ) R41 15k brown-green-orange
( ) R42 15k brown-green-orange

9710 VCA 5
000216
listed below: 18k brown-grey-orange
( ) R71 ( ) R81 ( ) R85 ( ) R87
listed below: 1k brown-black-red
( ) R25 ( ) R26 ( ) R80 ( ) R99
( ) R107
listed below: 220 red-red-brown
( ) R35 ( ) R36 ( ) R45 ( ) R46
( ) R98
( ) R20 2200 red-red-red
listed below: 220k red-red-yellow
( ) R16 ( ) R17 ( ) R75 ( ) R78
( ) R88 ( ) R97
listed below: 22k red-red-orange
( ) R23 ( ) R37 ( ) R47 ( ) R60
( ) R69
listed below: 33 orange-orange-black
( ) R1 ( ) R2 ( ) R62 ( ) R68
( ) R82 3300 orange-orange-red
listed below: 330k orange-orange-yellow
( ) R53 ( ) R55 ( ) R58 ( ) R83
( ) R84
listed below: 33k orange-orange-orange
( ) R51 ( ) R52 ( ) R70 ( ) R103
( ) R29 390 orange-white-brown
( ) R30 3900 orange-white-red
( ) R32 3900 orange-white-red
( ) R79 3900 orange-white-red
( ) R74 4.7meg yellow-violet-green
( ) R27 470k yellow-violet-yellow
( ) R86 470k yellow-violet-yellow
listed below: 47k yellow-violet-orange
( ) R31 ( ) R49 ( ) R54 ( ) R56
( ) R57 ( ) R59 ( ) R90 ( ) R101
( ) R106 ( ) R119 ( ) R120

6 9710 VCA 000216
( ) R22 6800 blue-grey-red
( ) R39 910k white-brown-yellow
( ) R43 910k white-brown-yellow
listed below: 91k white-brown-orange
( ) R61 ( ) R63 ( ) R72 ( ) R77
Disk Capacitors
Many of the capacitors used in the 9730 are nonpolarized
Ceramic Disk types. For each of these, either lead can go in
either of the holes in the circuit board. The leads are already
parallel to each other but still may need to be bent slightly to
match the spacing of the circuit board holes. Like the resistors,
insert the leads of these parts through the holes in the board
and push the part against the circuit board as far as it wants to go.
Don't force it, it's OK if it sits a little off the board.
Capacitors are often marked with obscure codes that
indicate their values. The 3 digit number that specifies
value may be preceded or followed by letters indicating
such things as tolerance. If you get confused about
which capacitors are which, it may help to group them
by same type and check them against quantities on the
packing list at the end of this manual.
DESIGNATION VALUE MARKING
( ) C18 0.005 502
( ) C22 0.005 502
( ) C23 0.005 502
listed below: 0.01 103
( ) C3 ( ) C5 ( ) C7 ( ) C9
( ) C10 ( ) C13 ( ) C17
listed below: 100pF 100
( ) C8 ( ) C11 ( ) C12 ( ) C14
( ) C15
Ceramic Disk
Capacitors

9710 VCA 7
000216
Electrolytic Capacitors
The remaining capacitors are electrolytic types.
Unlike the previous components, electrolytic
capacitors are polarized and the leads are not
interchangeable. Leads are marked "+" and/or "-"
and the "+" lead must go through the "+" hole in the
circuit board. Frequently the positive lead of the
capacitor is significantly longer than the negative lead.
Usually the Negative lead of the capacitor is marked rather
than the positive. It naturally goes through the unmarked hole.
Capacitors supplied with specific kits may have a higher
Voltage (V) rating than the minimum specified below.
DESIGNATION VALUE
( ) C20 10uF / 15V
( ) C21 10uF / 15V
( ) C16 1uF / 15V
( ) C1 220uF / 25V
( ) C2 220uF / 25V
( ) C19 33uF / 15V
( ) C4 4.7uF / 15V
( ) C6 4.7uF / 15V
Diodes
Like the Electrolytic Capacitors, diodes are polarized
and must be installed so that the lead on the banded
end of the part corresponds to the banded end of the
designator on the circuit board. Bend the leads so they
are at right angles to the body of the part and insert
them through the holes provided in the circuit board.
Diodes are also somewhat heat sensitive so the
soldering operation should be done as quickly as possible.
DESIGNATION TYPE
listed below: 1N4148 Silicon Diode
( ) D1 ( ) D2 ( ) D3 ( ) D4
( ) D5 ( ) D6 ( ) D7
Note diode
polarity band

8 9710 VCA 000216
Transistors
Install the transistors by inserting their three leads
through the holes provided for them in the circuit board.
Note that the transistors are polarized by the flat side
of the case. When the transistors are properly
installed this flat will align with the corresponding mark
on the circuit board legending.
Notice that two different types of transistors (2N3904 and 2N3906)
are used. The type will be written on the body of the part.
Two of the transistors have been specially selected to have
matching characteristics and will be packed together.
Keeping this pair together is important for optimum circuit
performance. Since they are matched, it makes no difference
which transistor is used for which designation.
DESIGNATION TYPE
( ) Q3/Q4 2N3904 NPN Si Transistor Matched Pair
One transistor has been selected for use as a noise
source and has one of its leads cut short.
( ) Q5 2N3906 Selected for noise.
Install the remaining transistors as follows:
listed below: 2N3906 PNP Silicon Transistor
( ) Q1 ( ) Q2 ( ) Q6 ( ) Q7
( ) Q13
listed below: 2N3904 NPN Silicon Transistor
( ) Q8 ( ) Q9 ( ) Q10 ( ) Q11
( ) Q12 ( ) Q14 ( ) Q15
Trimmer Potentiometers
The two trimmer potentiometers surface mount to the
board rather than having their leads pass through it.
First "tin" the trimmer mounting pads on the circuit boar
by melting a little solder onto them. Solder the trimmer
to the board by holding the pins against the tinned pads
and remelting the solder.
The straight line of the pc
graphic symbol corresponds
to the flat face of the
transistor case.
Note flat
Q5 has one lead removed
Trimmer potentiometers surface
mount by tinning the mounting
pads and remelting the solder to
the component pins
Note cut-off
lead

9710 VCA 9
000216
DESIGNATION VALUE MARKING
( ) R26 100k 100K
( ) R34 100k 100K
Integrated Circuits
Of all the parts, the ICs are the most easily damaged
and should be treated with some respect. In particular,
they may be destroyed by discharges of static electricity.
Modern ICs are not nearly as sensitive to this kind
of damage as were earlier versions, but it is still good
practice to handle these parts as little as possible.
Also good practice: don't wear nylon during assembly.
Don't shuffle around on the carpet immediately before
assembly (or if you do, touch a lamp or something to
make sure you're discharged). Don't be intimidated.
It's rare for parts to be damaged this way.
ICs are polarized in one or both of two ways; A dot
formed into the case of the IC corresponding to pin 1
or a semicircular notch that indicates the end of the
package with pin 1. Take care that this polarizing
indicator corresponds to the similar indicator on the
circuit board graphics.
The pins of the ICs may be splayed somewhat and not
match the holes in the circuit board exactly. Carefully
re-form the leads if necessary so that they are at right
angles to the part.
Solder each IC in place as it is installed by initially
soldering two pins in diagonal corners of the
pattern. Make sure that the part is seated firmly
against the circuit board by pressing it down while re-
melting the solder joint at first one corner, then
the other. Finally, solder the remaining
connections.
DESIGNATION PART NO. DESCRIPTION
( ) IC3 LM324 Quad OpAmp
( ) IC4 LM1496 Balanced Modulator
( ) IC5 LM13600 Dual OTA
( ) IC6 LM324 Quad OpAmp
( ) IC7 LM324 Quad OpAmp
LM13600
16 pins
Note pin 1
LM324
LM1496
14 pins

10 9710 VCA 000216
Voltage Regulators
The voltage regulators are polarized and
must be mounted so that their tabs correspond to
the tab markings on the circuit board graphics.
Solder all three leads and clip any excess off
flush with the solder joint.
( ) IC1 7912 -12V Voltage Regulator
( ) IC2 7812 +12V Voltage Regulator
LEDs
LEDs are polarized by the flat in the collar at the base
of part. When properly installed, this flat will align with
the corresponding flat in the LED symbol printed on
the circuit board.
When the 9730 is installed behind its front panel, the
LED will engage the hole in the front panel and be
supported by its leads. Install the LED by pushing it's
two leads through the holes in the circuit board. With
3/8" of space between the bottom of the LED and the
circuit board, solder one lead. Check spacing and polarization
before soldering the second lead and trimming both leads
off flush with the solder joint.
DESIGNATION TYPE
( ) LED1 Red LED
"Flying" Wires
(i.e. those which go from circuit board to panel mounted parts.)
In the following steps, wires will be soldered to the 9730 board
which in later steps will be connected to the front panel controls
and switches. At each step, cut a piece of wire to the specified
length and strip 1/4" of insulation from each end. Twist the
exposed wire strands together and "tin" them by melting a small
amount of solder into the strands. This will make soldering easier
when the wires are installed and prevents fraying
of the wire strands when they are pushed through
the holes. Solder each connection as it is made
and clip any excess wire from the solder side
of the board.
Leave about 3/8" space
between the circuit
board and LED base.
Note Tab
Note: If you also have the
9710frm FracRak
Accessory kit do not use
the wire from that kit in
these steps. 9710frm
wires are already cut to
length for use with the
power connector.
Flat
3/8"