Audio Note DAC Kit 4.1 User manual

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Manual Version 2.2 –March 2011
Build instructions for DAC3.1, DAC3.1 Signature, DAC4.1 Limited Edition

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Table of Contents
Section1: Introduction............................................................................................................................................................4
Overview............................................................................................................................................................................5
Component Placement Breakdown....................................................................................................................................6
Electrical Safety Warning...................................................................................................................................................8
Section 2: Mechanical Assembly...........................................................................................................................................9
Installing the feet................................................................................................................................................................9
Mains Transformer, Choke, and Mains Installation............................................................................................................9
Configuring the Primary Winding for your World Region..............................................................................................11
Installing the IEC Socket (AC Socket) and Rocker Switch ...........................................................................................14
Installing the Choke......................................................................................................................................................15
Installing the Mains Transformer ..................................................................................................................................15
Wiring up the Mains......................................................................................................................................................16
Shield Positioning.........................................................................................................................................................17
Section 3: M2 Power Supply................................................................................................................................................19
M2 Power Supply Board Parts List ..................................................................................................................................20
M2 Power Supply Board Construction Steps...................................................................................................................21
Installing the Valve Bases ............................................................................................................................................21
Installing the Resistors .................................................................................................................................................23
Installing resistors in the HT ADJUST position.............................................................................................................25
Zener Diode Installation................................................................................................................................................26
Electrolytic Capacitor Installation..................................................................................................................................27
Installing the Bridge Rectifier........................................................................................................................................29
Installing the Non-Polarized Capacitors........................................................................................................................29
Wiring the M2 Power Supply Board..............................................................................................................................30
Filament Component Section of the M2 Power Supply Board......................................................................................33
Regulator Installation....................................................................................................................................................34
Installing the LED Harness...........................................................................................................................................35
Remaining Wire Connections.......................................................................................................................................35
Installing the Heatsink ..................................................................................................................................................36
Installing the Choke Wire..............................................................................................................................................37
Inter-wiring to the Mains Transformer...........................................................................................................................38
Securing the Regulators to the Heatsink......................................................................................................................41
Section 4: M2 Power Supply Testing...................................................................................................................................43
Preparations.....................................................................................................................................................................43
Fitting the Mains Fuse..................................................................................................................................................43
Installing the LED Indicator...........................................................................................................................................44
Installing the tubes........................................................................................................................................................44
Tidying Up....................................................................................................................................................................44
Ohm Check......................................................................................................................................................................45
Electrical Testing..............................................................................................................................................................45
Voltage Check Summary .................................................................................................................................................47
DC Voltage Checks......................................................................................................................................................47
AC Voltage Checks ......................................................................................................................................................47
Section 5: Digital Power Supply PCB ..................................................................................................................................48
Parts List..........................................................................................................................................................................48
Construction.....................................................................................................................................................................48
Installing the LED‟s.......................................................................................................................................................49
Installing the Capacitors...............................................................................................................................................49
Installing the Diodes.....................................................................................................................................................50
Installing the Resistors .................................................................................................................................................51
Board Installation and Wiring...........................................................................................................................................52
Section 6: Install the Screen................................................................................................................................................54
Section 7: Installing the Digital PCB ....................................................................................................................................55
Digital Board Overview.....................................................................................................................................................55

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Digital Board Installation ..................................................................................................................................................56
Section 8: Digital Board Power Supply Connections...........................................................................................................57
Section 9: Line Board Construction .....................................................................................................................................58
Installing the Valve Bases................................................................................................................................................58
Parts List..........................................................................................................................................................................58
Installing the Resistors.....................................................................................................................................................59
Installing the Electrolytic Capacitors.................................................................................................................................61
Installing the Film (non-polarized) Capacitors..................................................................................................................61
Board Orientation.............................................................................................................................................................62
5687 Filament Wiring.......................................................................................................................................................62
Section 10: Installing I/V transformers.................................................................................................................................63
Wiring the I/V Transformers.............................................................................................................................................64
Section 11: Connecting the 5687 Output.............................................................................................................................65
Connecting the 5687 HT to the power supply..................................................................................................................65
Connecting the Output Transformers...............................................................................................................................65
Output Transformer Type 1 (Single-ended Only) .........................................................................................................66
Output Transformer Type 2 (Single-ended or Balanced)..............................................................................................67
Section 12: Source Selection and Switching .......................................................................................................................68
Installing the Input Selector Switch ..................................................................................................................................68
Input Connections............................................................................................................................................................69
Connecting the RCA Input............................................................................................................................................70
Connecting the USB Input............................................................................................................................................72
Connecting the XLR Input ............................................................................................................................................73
Section 13: Turn-on Procedure............................................................................................................................................74
Final Thoughts.....................................................................................................................................................................75
Appendix..............................................................................................................................................................................76
Resistor Color Code Reference .......................................................................................................................................77
Analog Board Schematic..................................................................................................................................................78
M2 Power Supply Board Schematic.................................................................................................................................79

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Section1: Introduction
NOTE: This manual is for the DAC3.1, DAC3.1 Signature, and DAC4.1 kits - The kits are all the same except that the
component level is increased with each kit the - The DAC3.1 can come as RCA or RCA/Balanced while the DAC4.1 using
the C-core output transformers comes in RCA/Balanced.
Thanks for purchasing the AudioNote DAC Kit 3.1 or 4.1. Our goal is to provide you with the highest quality Kit that you
will build from scratch with these instructions. If you have any questions or comments during the build feel free to contact
us and we would be happy to help out.
You will need a soldering iron or soldering station with a sponge along with wire strippers and a Phillips screwdriver. A nut
driver or a pair of pliers would be useful as well. We have divided the manual up into a series of step-by-step instructions
for the successful build and debug of the kit. There are several places during the build that you will perform tests and/or
checks to make sure that you are on track. This way when you complete the kit you will know that all the major sections
are working.
You will find a number of component bags supplied with your kit. These bags will be referred to throughout this manual.
Here are some tips from working with many kit builders over the last few years:
Perform your work in small manageable chunks. Do not be in a hurry to listen to your finished kit.
Savor the build experience. Here‟s a chance to really get to know your audio kit that will give you many hours of
enjoyment.
Better to work on a section and then spend the time to check over the section rather than just carrying on.
The kit building experience should be a pleasant one so find a place that you can build the kit with relative peace
so you can concentrate on the instructions.
If you plan for a long build stretch on a Saturday afternoon for example then take plenty of breaks with constant
re-checks of your work.
Whilst working through this manual, please feel free to give us your feedback and any other information that may allow us
to improve the build experience.

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Overview
Here is a rough guide to the steps you will be following. You may want to use this page as a general checklist, crossing
out each item as it is done.
1. Install Feet on Chassis
2. Install M2 Mains Transformer and Choke into chassis
3. Connect up IEC section (IEC/rocker, Mains transformer)
4. Build M2 Power Supply Board
5. Wire up Mains transformer to M2 power supply
6. Build DAC PS PCB
7. Wire up Mains transformer to DAC PS board
8. Build 5687 analog Board
9. Wire up Filaments and HT from M2 Power supply Board
10. Install Digital Board in chassis
11. Connect Digital Power Supply leads to Digital Board
12. Connect Digital Board to 5687 Board (via IV transformers)
13. Connect 5687 analog board to output transformers
14. Connect output transformers to audio outputs

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Component Placement Breakdown

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The graphic below shows the block diagram overview of how the DAC works:

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Electrical Safety Warning
There are sufficient voltages in this kit to give you a very nasty and harmful shock so be careful when powering
on, debugging, and probing around.
Please be aware of proper electrical safety.
Please contact AudioNote kits via phone or email to discuss any precautions necessary when building the kit if
you feel unsure about what you are doing at any stage of the build.

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Section 2: Mechanical Assembly
In this beginning section we will start by installing the 4 feet from the Fittings Bag then we will install the Mains transformer
and Choke as shown in the pictures below.
Installing the feet
Insert 4 feet in the bottom of the chassis.
Fix them each in place using an M4 nut and washer.
Mains Transformer, Choke, and Mains Installation
Above you can see the Mains transformer that is used with the M2 Power Supply. The first step is to take the supplied M4
GND lug from the Hardware Bag and solder it to the end of the green wire.

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Trim the wire to about __ inches.
Strip about ¼” of insulation off the end of the green wire.
Tin the bare wire by adding solder to the end.

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Add solder to secure the GND Lug to the end of the wire.
Configuring the Primary Winding for your World Region
Next step is to decide what world voltage you require –for example we have some of the most popular regions listed
below:
United States
120v
Canada
120v
UK
230v or 240v
Europe
230v / 240v
Hong Kong
220v
In order to wire up the for 120V operation we will need to connect the primaries as shown below:
The graphic shows above the correct wiring for of the Primaries for 120V operation where the 0 of one winding connects
to the 0 of the second winding & the 120 of one winding connects to the 120 of the second primary winding. Check the
chart on the next page for the correct PRIMARY winding for the world Voltage you live in.

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Now we must configure our Mains transformer for the World Voltage that we reside in. For this example we will show
120V Operation.
Start by cutting two short pieces of
wire approx 2” in length each, stripping
the insulation off the ends and tinning
the wire.
Then we will inter-wire the Mains transformer primaries.
Remember, we are wiring here for 120v - if your region is
different then you will need to consult the wiring chart on
the previous page to determine how you inter-wire for your
region.
From the IEC bag we want to take the brown and blue
wires with the crimps on one end.
Trim the wires to about _____ inches in length and then
solder on to the correct Mains transformer primary tags for
your region.

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Here, the wires are soldered onto the top-most 0v and the
bottom-most 120v for North American/Canadian 120v.
Remember, we are wiring here for 120v - if your region is
different then you will need to consult the regional wiring
chart to determine how you inter-wire for your region.
Installing the IEC Socket (AC Socket) and Rocker Switch
The rocker switch simply snaps into
pace in the chassis slot.
Use the CSK M3 10mm screw and M3
nut to secure the IEC socket into
position.
Here you can see the correct installation of the IEC socket
and rocker switch from inside the chassis.

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Installing the Choke
Since the Choke fits into a tight
location we suggest you put the
screws and washers into position
through the holes in the choke covers
–then lower the choke into position
making sure that you align with the
non painted hole - see opposite.
Note the wires at the back of the
choke.
The left-most picture shows the final
position of the choke from inside the
chassis.
The central picture shows its position
under the chassis where you will now
secure the 4 holes of the choke with
serrated M4 washers and M4 nuts.
Installing the Mains Transformer
The picture opposite shows the correct orientation for the
Mains Transformer.
The following instructions will show how this is achieved.

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When installing the Mains transformer
be sure to line it up with the unpainted
hole in order to ensure a ground
connection.
Secure the transformer at all four
corners.
Wiring up the Mains
Once the transformer is installed you can connect up the
Blue and Brown Crimped wires from the Mains transformer
directly to the Rocker Switch.
Also connect the green earth wire from the mains
transformer to the GND lug as shown opposite.

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Add the twisted wire (Cable #3) and the ground wire (Cable
#4) as shown in the graphic opposite.
Let‟s add one final GROUND wire connection from the M4
screw in the chassis.
Take a piece of bare wire and solder it between the V300
and 0 terminals as shown opposite. Next, take a terminated
ground wire and strip the un-terminated end and solder it to
the short that you have just made. The other, terminated,
end connects to the chassis ground post.
Shield Positioning
I would like to explain where the shield fits at this stage –you won’t actually be installing this until the end of the
build but by then there will be a number of things inside the chassis.
Take a look at the shield provided and locate the hole underneath that has no paint on it –this will match up with a hole
on the chassis that is also unpainted in order to ensure a good grounding of the SHIELD when in stalled in the chassis.

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Here you can see the correct
installation of the shield –You will
need to remove it later on when we
wire up to the Mains transformer but
for now you can leave it in and show
off your wonderful work to your wife!
This concludes the IEC Wiring section for the Mains Transformer.
You may want to double-check your work at this point. Also, make sure that the crimped end on the Rocker switch are not
coming into contact with each other - make sure there is plenty of clearance. If you want to add some solder to hold them
into place that is fine but I would wait a little bit. Also remember that you can use the rubber hoods that are supplied to
cover up the rocker and IEC plug and it is a matter of threading the crimped end through the rubber hood.
With this section completed we are going to move onto the building of the M2 Power Supply Board.

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Section 3: M2 Power Supply
In this section we will be assembling the M2 Power Supply Board PCB.
Here is a view of the parts that you will find in the M2 Power Supply Kit Bag
Most of the parts for this section can be found in the M2 Power Supply bag (although the filament wires may be located
elsewhere).
For an experienced builder you can look at the parts list on the next page and get started but I would read through the
step by step instructions as we feel that this is the best and most efficient error free method of building the board.

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M2 Power Supply Board Parts List
The Complete Parts list for the M2 board is shown below.
For resistor color code chart refer to the APPENDIX. You can also find an 'Interactive Resistor Color Code Calculator' on
our website (available from the Links page).
Category
Quantity
Part
Designator
Capacitors (Electrolytic)
2
470uf 16V
C2, C4
1
2200uF 35V
C9
2
22uF 450V
C6 ,C7
2
68uF 450V
C3, C5
Capacitors (Non-polarized)
1
Disc 4700uF 1000v
C10
1
.22uf 600V
C8
1
.47uF 600V
C1
Resistors
1
100R
R8
2
1K0
R5, R6
1
2K7
R12
1
15K
R11
1
33K
R2
1
68K
R3
2
100K
R1, R10
1
150K
R7
1
220K
R9
1
470K
R4
Semiconductor Devices
1
KBU6J6A
U1
1
3.5W 150V Zener
D7
4
Zero Ohm Resistors
D1, D2, D4, D5
2
1N4007
D3, D6
2
78S12
U2, U3
Variable Resistor
NOTE: This may be replaced with 2x 22K resistors
1
50K 500mW
VR1
Valve Bases
1
8 pin valve base
1
9 pin valve base
Tubes
1
6X5 Tube
1
ECL82 / 6BM8 tube