AkitikA PR-101 User manual

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PR-101STEREO
PREAMPLIFIER
ASSEMBLYMANUAL
© 2014 AkitikA LLC
All rights reserved
Revision 4p16 November 29, 2014

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Table of Contents
Table of Contents................................................................................................................ 2
Table of Figures.................................................................................................................. 4
Section 1: About This Manual............................................................................................ 5
Who Should Attempt this Project? ................................................................................. 5
Tools you’ll need ............................................................................................................ 5
Helpful Tools.................................................................................................................. 5
Project Overview ............................................................................................................ 5
Important Safety Notes................................................................................................... 6
About Components ......................................................................................................... 6
Recommended Solder..................................................................................................... 6
Warranty ......................................................................................................................... 6
Section 2: About Building the Kit ...................................................................................... 7
Section 3: Building the Power Supply PCB ....................................................................... 8
Component Order............................................................................................................ 8
Install the Diodes ............................................................................................................ 8
Install the non-polarized Capacitors ............................................................................... 9
Install the Not so Tall Polarized Capacitors ................................................................. 10
Install the Fuse and Fuse Holder................................................................................... 10
Install the Tall Polarized capacitors.............................................................................. 10
Install the Regulators and Heat Sinks........................................................................... 11
Install the voltage select jumpers.................................................................................. 12
Install the AGND-BGND jumper................................................................................. 13
These Components Are Not Loaded............................................................................. 14
Power Supply Inspection .............................................................................................. 14
Section 4: Assembling the Tone-Volume-Balance Board................................................ 15
Install the Resistors....................................................................................................... 15
Install the Diodes and Low Profile Capacitors............................................................. 16
Install the Relay and the Manual Pots........................................................................... 17
Install the Tall Capacitors............................................................................................. 18
Install the Electrolytic Capacitors................................................................................. 18
Install the Integrated Circuits and Transistor................................................................ 18
Install the Control Cable Connector ............................................................................. 19
Install the Motor Pots.................................................................................................... 19
Install Tone/Volume Power Wiring.............................................................................. 21
Install Signal Cables ..................................................................................................... 21
Section 5: Assembling the Input Selector Board.............................................................. 23
Install the Resistors....................................................................................................... 23
Install the Small Capacitors.......................................................................................... 25
Install the Diodes .......................................................................................................... 25
Install the Bypass Capacitors........................................................................................ 26
Install the Integrated Circuits........................................................................................ 26
Install the Control Cable Connector ............................................................................. 26
Install the Relays........................................................................................................... 27
Install the Transistors.................................................................................................... 28

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Install the Tall Film Capacitors..................................................................................... 28
Install the electrolytic capacitor.................................................................................... 28
Install J1 and J2............................................................................................................. 28
These Connectors Are Not Populated........................................................................... 29
Install Input Selector Power Wiring ............................................................................. 29
Take a Break................................................................................................................. 30
Section 6: Assembling the Controller............................................................................... 31
Component Side............................................................................................................ 31
Install the Resistors....................................................................................................... 31
Install the non-polarized Capacitors ............................................................................. 32
Install the IC’s and Transistor....................................................................................... 33
Install the Resistor Networks........................................................................................ 33
Install the Ferrite Beads................................................................................................ 34
Install the Control Cable Connectors and Controller Socket........................................ 35
Install the Polarized Capacitors .................................................................................... 36
You’ve Finished this Side of the Controller PCB for Now...................................... 37
Install the Push Buttons ................................................................................................ 37
Install the Infrared Detector.......................................................................................... 38
Install the LEDs ............................................................................................................ 39
Install the Last Two Capacitors .................................................................................... 40
Install the Microcontroller ............................................................................................ 41
Install the Controller Power Wire................................................................................. 41
Section 7: Chassis Assembly and Power Wiring.............................................................. 43
Protect your PR-101...................................................................................................... 43
Install the feet................................................................................................................ 43
Install the IR Detector Window.................................................................................... 43
Install Back Panel Power Connectors and Front Panel Power Switch ......................... 44
Power Wiring................................................................................................................ 44
Section 8: Preliminary Final Assembly............................................................................ 45
Wire and install the front panel input connector........................................................... 45
Install the headphone jack............................................................................................. 45
Install the power supply................................................................................................ 45
Prepare to Test the power supply.................................................................................. 47
Test the power supply................................................................................................... 47
Install the Controller PCB............................................................................................. 48
Connect Power to the Controller PCB.......................................................................... 48
Test the Controller PCB................................................................................................ 48
Test the Remote Control............................................................................................... 49
Connect Power to the Input Selector PCB.................................................................... 49
Test the Input Selector PCB Step 1............................................................................... 49
Test the Input Selector PCB Step 2............................................................................... 49
Connect Power to the Tone Volume PCB .................................................................... 50
Test the Tone Volume PCB Step 1............................................................................... 50
Test the Tone Volume PCB Step 2............................................................................... 50
Section 9: Final Final Assembly....................................................................................... 51
Tone Volume to Input Selector Signal Connections..................................................... 51

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Final Mechanical Assembly.......................................................................................... 52
Section 10: About the Preamp Architecture ..................................................................... 52
Features......................................................................................................................... 52
Block Diagram.............................................................................................................. 53
Table of Figures
Figure 1-Empty the power supply components into a soup bowl....................................... 8
Figure 2-Component side of power supply PCB before loading........................................ 9
Figure 3-Fuse holder body solders into board, installing fuse into lid of fuse holder...... 10
Figure 4-Assembling Heatsink to a Regulator.................................................................. 11
Figure 5-Solder heat sink mounting rods to retain the heat sink...................................... 12
Figure 6-Preparing voltage jumper wires ......................................................................... 12
Figure 7-120 Volt Operation Jumper installation............................................................. 12
Figure 8-240 Volt Operation Jumper installation............................................................. 13
Figure 9-Power Supply before transformer is installed, wired for 120 Volts................... 13
Figure 10-Install AGND to BGND jumper ...................................................................... 14
Figure 11-Silkscreen side of the Tone Volume Board shows component locations ........ 15
Figure 12-Remember to match silk screen and IC orientation mark................................ 18
Figure 13-Identify pin 1 for proper connector installation ............................................... 19
Figure 14-Motor POT wire preparation............................................................................ 19
Figure 15-Motor POT wiring detail.................................................................................. 20
Figure 16-Completed Tone/Volume Board...................................................................... 20
Figure 17-Silkscreen side of the Input Selector Board shows component locations........ 23
Figure 18-Assembled Input Selector board...................................................................... 29
Figure 19-Silk screen of the “component side” of the controller PCB............................. 31
Figure 20-Insert all the IC’s so that the U-shaped indent matches the silk-screen........... 33
Figure 21-10 pin cable conector pinout............................................................................ 35
Figure 22-locating the pins on the 16 pin cable connector............................................... 35
Figure 23-showing socket orientation............................................................................... 36
Figure 24-Switch and LED side of Controller Board....................................................... 37
Figure 25-Forming the leads of a free-standing infra-red detector (left) or installing the
framed IR detector (right)................................................................................................. 38
Figure 26-LED with white spacer added.......................................................................... 39
Figure 27-Retaining LEDs with masking tape.................................................................. 39
Figure 28-Completed controller, push-button and LED side............................................ 41
Figure 29-Install 4 feet with 6-32x1/2" silver colored screws.......................................... 43
Figure 30-Installing power outlets and IEC connector...watch orientation! Installing the
power switch…watch orientation!.................................................................................... 44
Figure 31-Fasten the transformer to the preamp right side wall....................................... 46

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Section 1: About This Manual
This manual gives the information needed to build Akitika LLC’s PR-101 Stereo
Preamplifier.
Who Should Attempt this Project?
You can build this kit if you can:
1. Solder (using normal rosin core solder and a soldering iron).
2. Use simple hand tools like screwdrivers, wire cutters, and pliers.
3. Read and follow directions.
It helps if you:
1. know a bit about electronics, or
2. have a friend who knows a bit about electronics
3. can get to YouTube to watch a few helpful videos about the assembly process
(none are posted as of this version of the manual).
Tools you’ll need
You’ll need the following tools:
1. Phillips screwdriver (#1 and #2)
2. Pliers or nut drivers suitable for #4 and #6 hardware
3. needle nose pliers (helpful, but not strictly necessary)
4. pencil type soldering iron of 25 to 50 Watts (no huge honking soldering guns or
blowtorches)
5. wire cutters and strippers
6. multi-meter to measure power supply voltages and confirm resistor values
(strongly recommended)!
Helpful Tools
These tools aren’t strictly necessary, but make building the kit easier.
1. magnifying glass, if you’re over 42!
2. lead bending jig to form axial component leads to the correct span for insertion in
the PCB.
Project Overview
The project consists of the following steps:
1. Building these circuit boards:
a. Power Supply
b. Controller
c. Input Selector
d. Volume/Tone Control
2. Install and wire the circuit boards, switches, connectors, and power transformer
into the chassis.

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Important Safety Notes
By purchasing, using, or assembling this kit, you have agreed to hold Akitika LLC
harmless for any injuries you may receive in its assembly and/or use. To prevent injuries:
Wear safety glasses when soldering to prevent eye injuries.
Always unplug the power before working on the amplifier.
Large capacitors hold lots of energy for a long time. Before you put your hands
into the amplifier:
oPull the AC plug!
oWait 2 full minutes for the capacitors to discharge!
Remove jewelry and rings from your hands and wrists, or anything that might
dangle into the amplifier.
If working one the equipment with the power on, keep one hand in your pocket,
especially if you’re near the power supply or power supply wires. This can
prevent serious shocks.
Build with a buddy nearby. If you’ve ignored all the previous advice, they can
dial 911 or get you to the hospital.
About Components
We reserve the right to make design/or component changes at any time without prior
notification.
Recommended Solder
The kit must be assembled with 60/40 Rosin Core solder. The recommended diameter is
0.032 inches. Among many such sources of solder, I have used Radio Shack part number
64-009. It contains 8 oz. of solder, which is much more than you’ll need to assemble the
PR-101 kit.
Warranty
With the exception of fuses, Akitika will replace for free any parts of a correctly
assembled PR-101 that fail within one year of the date of purchase when the amplifier
has been used in home stereo applications. It is the responsibility of the kit builder to
install the replacement part(s). This warranty applies to the original purchaser only. It
does not apply to units that have been physically or electrically abused, modified without
prior factory authorization, or assembled with other than 60/40 Rosin Core solder.
Akitika LLC’s liability shall in no event exceed the cost paid to Akitika LLC for the kit.

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Section 2: About Building the Kit
Yes, I know you want to ignore this section, and jump right into building the kit.
However, please take a minute and read the advice of this section. I’ve condensed it into
bullets so that even you guys who are in a hurry can benefit.
There are 4 PCB’s to build:
oPower supply
oTone/Volume
oInput Selector
oController
Stop any time you’re feeling confused, tired, or anxious. Taking breaks at those
strategic times will keep the build enjoyable and greatly enhance your chances of
first-time success.
Finish one PCB before you build the next.
A soup bowl is your friend. Before you build a board, carefully empty the parts
for only that board into a broad, flat, light colored soup bowl. That makes it easy
to find the parts, and keeps them from getting lost.
A digital ohm-meter is an easy way to make sure that you’ve picked the right
resistor. It’s a great cross-check on the resistor color code. Measure twice and
solder once!
A lead-bending jig can make for quicker, neater assembly. It’s certainly not
necessary.
Is something in this manual confusing? Does something look wrong? Send your
questions by email to [email protected]om. You’ll help yourself and everyone who
builds the kit.

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Section 3: Building the Power Supply PCB
This section details the process of building the power supply circuit board. Begin by
carefully emptying the contents of the envelope marked “PR-101 PSU Module” into a
broad soup bowl, as shown below. In general, you’ll start with the components that lay
closest to the board, working your way towards the taller components.
Figure 1-Empty the power supply components into a soup bowl
Component Order
You’ll notice that the component designations in the directions don’t go exactly in order.
We have grouped them so that all components with the same value appear together. This
makes assembly easier. You’ll find in the parts kit that similar parts, e.g. 3 1K resistors,
are typically (though not always) taped together.
Install the Diodes
In general, you install axial leaded components (like the 1N4004 diodes) by placing the
body on silk screen side of the board, and the leads through the indicated holes. Bend the
leads over on the back of the board to keep the resistors from falling out until your solder
them in place. Try to bend the leads in a direction that won’t lead to solder bridges
between traces that should remain disconnected.
We recommend the following procedure:
1. Insert all components of the same value or type
2. Bend the leads as described above.
3. Solder the leads on the back of the board.
4. Clip the leads.
Track your progress by placing a check-mark in the done column as you install each
component. If you’re using a lead bending jig, use the 0.45” width for all the diodes.
Diodes – Polarity is important!
Make sure that the banded ended of the diode matches the banded end of the silk screen
Use 0.45” spacing for lead-bending jig (optional) for 1N4004 diodes
Designation Type Rating, Marking Done? ()
D3 1N4004 400 PIV 1 Amp, 4004
D4 1N4004 400 PIV 1 Amp, 4004
D5 1N4004 400 PIV 1 Amp, 4004

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D6 1N4004 400 PIV 1 Amp, 4004
D7 1N4004 400 PIV 1 Amp, 4004
D8 1N4004 400 PIV 1 Amp, 4004
D9 1N4004 400 PIV 1 Amp, 4004
D10 1N4004 400 PIV 1 Amp, 4004
D11 1N4004 400 PIV 1 Amp, 4004
Use 0.5” spacing for lead-bending jig (optional) for 2A04 diodes
D1 2A04 400 PIV 2 Amp, 2A04
D2 2A04 400 PIV 2 Amp, 2A04
D12 2A04 400 PIV 2 Amp, 2A04
D13 2A04 400 PIV 2 Amp, 2A04
Figure 2-Component side of power supply PCB before loading
Install the non-polarized Capacitors
The capacitors we install in this section can be installed in either orientation.
Non Polarized Capacitors
Designation Value Rating, Marking Done? ()
C1 0.1 µF
100 V Ceramic, 104 (stands for 10104=105pF =0.1
µF
C2 0.1 µF 100 V Ceramic, 104
C3 0.1 µF 100 V Ceramic, 104

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C4 0.1 µF 100 V Ceramic, 104
C7 0.1 µF 100 V Ceramic, 104
C8 0.1 µF 100 V Ceramic, 104
C5 0.01 µF 400 V Mylar, 10n (stands for 10 nano-Farads)
C6 0.01 µF 400 V Mylar, 10n (stands for 10 nano-Farads)
C18 0.033
µF 300 V AC, box shaped cap
Install the Not so Tall Polarized Capacitors
It’s important to install these caps with the proper polarity. The negative end of the cap is
marked with a minus sign. The silk screen on the board marks where the positive end of
the cap goes. Make sure that the negative end of the cap is away from the plus sign on the
circuit board. Polarized Capacitors – polarity matters!
Designation Value Rating Done? ()
C9 22 µF 35 V electrolytic
C10 22 µF 35 V electrolytic
C11 22 µF 35 V electrolytic
C12 22 µF 35 V electrolytic
C13 22 µF 35 V electrolytic
C14 22 µF 35 V electrolytic
Install the Fuse and Fuse Holder
Solder the body of the fuse holder to the PCB.
Figure 3-Fuse holder body solders into board, installing fuse into lid of fuse holder
Insert the 0.25 Amp (for 120-Volt operation) or the 0.125 Amp (for 240-Volt operation)
fuse into the fuse holder lid. Fit the lid into the body to complete fuse installation.
Install the Tall Polarized capacitors
Polarized Capacitors – polarity matters! Double check the rated voltage!
C15 4700 µF 35 V electrolytic
C16 4700 µF 35 V electrolytic
C17 4700 µF 16 V electrolytic