ANKits L4 Series Instructions for use

L4 EL34p Power Amplifier
Construction Manual
Version 1.14, June 2019
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1-613-822-7188

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Table of Contents
Section 1 —Introduction
1.1 About ANKits …………………………………………..……………………………………………..……………………….… 6
1.2 Evolution of the L4 EL34p Power Amplifier …………………………….…………..…….……………………… 7
1.3 Overview ……………………………………………………………………………………….….…….……………………….… 8
1.4Basic Operation of the Amplifier ……………………………………….……….………………………………….… 10
1.5Equipment …………………………………………………………………………....……………….………………………….. 10
1.5.1 Overview of the Kit .………………….………………………………..…….............…………………………… 10
1.6Tips and Suggestions ………………………….…………………………………….….….……….…………………........ 10
1.6.1 Soldering ……………………………....….....................................……....…….…………………................... 10
1.6.2 Components ………………………………..……………………………….....…..........…………………............. 10
1.6.3 Resistor Sizes ……………………………..…….............................................…………………................... 11
1.6.4 Capacitor Voltage Ratings ………..……...........................................….………………..................... 11
1.6.5 Electrolytic Capacitors ……………..……................................................………………..……………... 11
1.6.6 Diodes …………………………………..……................................................……………............................... 11
1.6.7 Hardware/Mechanical …………..……........................................…….…….........……………………… 11
1.6.8 Wire Stripping and Tinning …..……....................................................………………………………… 12
1.6.9 Wire Color .…………………………..…….....................................................……………………..………….. 12
1.6.10 Optional Finishing Touches .…………………………..…….....................................………………….. 13
1.7Build Process …………………………………………………..………………………………………………………………….. 14
1.7.1 Some Good Rules of Thumb for Building Your Headphone Amplifier …………………...... 14
1.7.2 Organization of this Manual ……………….…….…………………………...........………………………… 14
1.7.3 Electrical Safety Warning ……………….…….…………………………...........…………………………..… 16
Section 2 —Feet, IEC and Rocker Switch Installation
2.1 Overview ….……………………...................………….…………………………………………………………..…………….. 17
2.2 Feet Installation ….…………..................………….…………………………………………………………………..…….. 18
2.3 IEC and Rocker Switch Installation ………….…………………………………………………………………..…….. 19
Section 3 —Mains Transformer installation
3.1 Mains Transformer Installation ………….………………………………………………………………………………. 20

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Section 4 —IEC PCB Installation
4.1 IEC PCB Wiring ………...……………………………………………….…………………………………………….…..……… 21
4.2 Mounting the IEC PCB ……,.………………………………………….…………………………………………….…………. 25
4.3 Additional Mains Wire Preparation ….……………………….…………………………………………….………... 25
Section 5 —Choke installation
5.1 Choke Installation ….……………….……………………………………………………………………………….………… 27
Section 6 —Power Supply PCB Installation
6.1 Overview ….………………………………………………………………….….………………………………………………….. 28
6.2 Parts List ………………………………….….………………………………….………………….………………….…………... 29
6.3 Building the Power Supply PCB ….………………………………….………………….………………………………. 29
6.4 Mounting the Power Supply PCB ….…….………………….………………………………………………………….. 30
Section 7 —ECF80/EL34 PCB Installation
7.1 Overview ……………………………………..…………..…………….………………….…………….…………………………... 31
7.2Building the ECF80/EL34 PCB ……..…………..…………….………………….…………….…………………………... 32
7.2.1 Resistor Installation ……………………………..........................……....…….………………….................. 33
7.2.2 Capacitor Installation ……………………………....….....................................……......…..................... 34
7.3Final Assembly of the ECF80/EL34 PCB ….…….……….……………………………………………………………. 35
Section 8 —Speaker Posts, RCA Jacks Installation
8.1 Speaker Posts, RCA Jacks Installation ….……………….........................................……………………………. 36
8.2 Wiring the RCA Jacks ….…………………………………….….........................................……………………………... 37
Section 9 —Output Transformers Installation
9.1 Output Transformers Installation ….…...…………………………………..…….……………………………………. 38
9.1.1 Wiring the Speaker Posts ….…...……………………………..……..…,….……………………..……………….. 40
9.1.2 Initial Wiring of the Output Transformers ….…...……………………………..……..….………………. 41

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Section 10 —Interwiring
10.1 Power Supply PCB Interwiring …….……………………………………….……………………………………………. 43
10.2 ECF80/EL34 PCB Interwiring …….…………..…………………………………………………..………………………. 44
10.2.1 Wire Routing ….…………………...…………………………………..…,….……….………………………………… 44
10.3 Mains Secondary Interwiring …….………………………………………………………….…..……………………… 45
10.4 Output Transformers Interwiring …….………………………………………………………..……………………… 45
10.5 Speaker Posts Interwiring …….…………………………………………………………………..……………………….. 45
10.6 Input Signal Interwiring …….……………………………………………………………………..……………………….. 46
10.6.1 Left/Right Channel Orientation ….…………………...……………………………….………………………. 46
10.7 LED Installation …….…………………………………………………………………………….…..………………………….. 47
10.8 Interwiring Chart …….………………………………………………………………………………….………………………. 48
Section 11 —Testing
11.1 Power On and Voltage Checks ….………………………………………..…….………….……………………..………… 50
11.1.1 Mains Fuse Installation ……..................……...........................………................................................ 50
11.1.2 AC Voltage Checks ……...........……................…………………………………........................................... 50
11.1.2 DC Voltage Checks ……...........……................…………………………………........................................... 51
11.2 Install the Tubes ….....……………………………………………………….....………………………………………………… 51
11.2.1 Checking Amplification ….....……………………................................................................................. 52
Section 12 —Finishing Touches
12.1 Installing the Front Faceplate….....………………………….………................................................................... 53
12.2 Installing the Chassis Top….....……………………............................................................................................ 53
Section 13 —Congratulations and Final Thoughts
13.1 Congratulations and Final Thoughts ….……………………………………..……………………………………… 545
13.1.1 Tube Rolling ………………….…..................……...........................………................................................ 54
13.1.2 Thanks ………………….................................……...........................………............................................... 54
Appendix ……………………………………………..…………………………………………….……..…...…….……….…...…. 55
A.1 Resistor Color Code Reference …………………………………………….…….………………...…..…….…….... 56

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Section 1
Introduction
Congratulations on your purchase of the ANKits L4 EL34p Power Amplifier. This is very high
end and sophisticated piece of audio equipment that will surely become the showpiece of your
sound system! We are excited you have chosen to join us on the path of audio superiority, and
thus, we have created this manual to help guide you through each step of the assembly process
with as much detail and clarity possible. To facilitate the build, the manual has been divided
into a number of sections, each focusing on a separate aspect of the system; follow through the
sections in order and we guarantee not only a problem free experience, but a pleasant time
doing so. If you are new to kits, or if at any time you feel as though you need help or advice, feel
free to contact us and we will do whatever it takes to get you on the right track.

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1.1 About ANK Audio Kits
Audio Note (UK) started out in the early '90s developing several DIY audio kits while they were
building up their finished product business. DIY Audio has a long history and it was an
opportunity for knowledgeable customers to take advantage of world class designs and
components. Audio Note (UK) was focused on using the very finest materials and components
custom-made to their specifications, across their entire product line —from custom film and
electrolytic capacitors to tantalum resistors, transformers, binding posts, wires, etc. The Kit1
300B Single Ended integrated amplifier was born during development of the Meishu and it
proved to be extremely popular worldwide. The ANKit business was born!
As the finished product business and dealer network started to flourish, Audio Note (UK)
eventually moved the kit business off into a separate division; thus, in 2004, Audio Note Kits
started up and was supported by a website so that customers not located near Audio Note (UK)
dealers could order kits and have them shipped direct. Kit development continued in earnest
during the 2000s with development assisted by Audio Note (UK) engineering. Audio Note (UK)
parts were used throughout the kits, depending on the various levels and budgets. By 2013,
ANK Audio Kits (as it came to be called) had developed a wide product range covering all areas
of two channel audio: a single-ended 300B product line, an EL34 classAB and single-ended
product line, digital to analog converters, pre-amplifiers, Phono stages, and Audio Note (UK)
speaker kits. The end result today is that customers worldwide with DIY skills can now build
an entire high end audio system to their liking. With the introduction of higher levels in 2013
and the release of the Level 5 Mentor Pre-amplifier and the DAC 5.1 Signature, some customers
wanted these high end products assembled by a professional builder. As a result, ANK Audio
Kits began offering this service for Level 4 and 5 products so that a significant investment in a
kit could be turned into a work of art! Since ANK Audio Kits was born in 2004, over 2,500 kits
have been shipped to customers worldwide. Clearly, there is a real demand for high end audio
kits and ANK Audio Kits has been delivering the goods now for 15 years.
We believe and hope that you will have a great experience building your kit and we look
forward to hearing from you about your experience.
Regards,
Brian Smith —Director ANK Audio Kits

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1.2 Evolution of the L4 EL34p Amplifier
AudioNoteKits was formed back in 2004 when the AudioNote DIY business was separated into a
business unit focused on the kit market. The single ended 300B Kit1 was the amplifier that
started the business and made it popular –we followed with pre-amplifiers, DACs and Phono
stages, as well as more single ended amplifiers.
Many customers/audiophiles were asking about higher power amps but they also wanted
ultra high quality sound. The EL34p Power Amplifier L4 was born in 2008 and we showed it at
the Rocky Mountain Audio Fest that year –Andy Groves' pentode design blew everyone away
with its presentation, warmth and overall sonics! We sold quite a few of them but continued
making enhancements along the way, including a re-architected major PCB and enhanced
power supply. The amplifier runs in class AB1 mode providing about 35W of pure EL34 power.
The amplifier has the detail of a single ended amplifier and the slam of push pull –ideal for all
sorts of music, especially guitar dominated rock! It's also gorgeous on female vocals and really
brings drums to life –ideal on digital as well, as it has a warm presentation but also really
kicks on those 70’s rock albums!
The build of the amplifier is our best yet –we have an excellent mechanical and electrical side
to the build –large high quality transformers make the amp weigh a hefty 30 lbs! It’s a
beautiful presentation so the WAF is high! No one will ever believe it is a kit!
Have fun with your amplifier –a throwback to the glory days of HI-FI in the early 60’s – truly a
remarkable beast and something you can be very proud of!

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1.3 Overview
Welcome to the L4 EL34p Amplifier Manual –the manual will guide you through the complete
build and test of the amplifier. Please remember, if you have any questions, please don't
hesitate to contact [e-mail].
Above you can see the general layout of the amplifier: this includes, starting from top right and
moving clockwise, the
Mains transformer T-190
Choke (CH-100W)
Power Supply PCB
ECF80/EL34 PCB
Output Transformers (OP-390 shown)
Before we begin let's familiarize ourselves with the basic operation of the amplifier.

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1.4 Basic Operation of the Amplifier
The Audio Signal enters the amplifier via the RCA jacks on the back of the unit - the left and
right audio go directly to the input of the large ECF80/EL34 PCB. This PCB connects to the
Output Transformers Primary –the Secondary or “output” of the Output Transformer connects
to the speaker posts. The ground and 8 ohm connections of the speaker posts connect back to
the ECF80/EL34 PCB –this is the feedback. That is the complete audio path of the EL34p
Amplifier.
Power
Supply
PCB
ECF80/EL34 PCB
Output
Transformer
Output
Transformer
RCA in
Speaker Post
Feedback
L4 –EL34 Amplifier BLOCK DIAGRAM Overview
The power supply consists of the Mains transformer and Choke, IEC/IEC PCB and rocker switch
–the AC 120V (North America) enters into the amplifier through the IEC and is sent to the
Primary of the Mains transformer where it is converted to various AC voltages that are
required by the amplifier. The first AC voltage is 0-275 AC which is used to create the HT (High
Tension) or maximum DC voltage that is required for the tubes to operate –it also creates a
pair of 6.3V AC 6A pairs which are used as filaments for the EL34 tubes to “light up”. Another
6.3V AC 1A pair is used to supply the filament voltage for the ECF80 driver tubes.

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1.5 Equipment
Here is the list of equipment that will be required:
Philips screwdriver
A pair of quality wire strippers
A large, organized work area
Soldering iron station with wet sponge
Lead-based solder (4% Silver is recommended)
1.5.1 Overview of the Kit
In your kit you will find a series of kit bags containing all the hardware, wire, and parts for the
associated sections of the amplifier. See the Parts List files on the disk to match up the parts in the kit
bags with the lists. There is also a Master list for the kit.
1.6 Tips and Suggestions
We have learned a lot about kit building over the last decade from our customers and I'd like to share
some tips with you to ensure a successful project. Please read through this section thoroughly, it will
give you a good idea of what's ahead and help ensure your success!
1.6.1 Soldering
We highly recommend using lead-based solder with some silver content1on the build. You should use
lead-free ONLY if you are experienced using it and confident. Lead-free solder requires a higher melting
temperature and thus is more difficult to use. We don’t recommend lead-free solder for first-time
builders.
We suggest that you practice your soldering before starting on the kit. Feel free to request practice parts
with your kit so that you can practice tinning wires and making nice solder joints. The key is a good
soldering station with a sponge, the right temperature, a good size tip, and experience; remember, tips
can wear out so make sure your tip is working. (You can also check out YouTube videos for soldering
lessons and examples.) The solder should flow freely; if it’s forming balls then there is likely a problem
with the tip, the temperature, or (sometimes) the surface. Feel free to contact us for help!
1.6.2 Components
Using the Ohm setting on your multimeter is very useful when building a kit. It's a good, practical way
of measuring resistors and continuity and is much easier than reading the color codes on the side. (With
practice, the color codes can also be a good way to determine the resistance, but that method is better
left to experienced builders.)
1For example, WBT-0800.

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1.6.3 Resistor Sizes
Resistors today, particularly metal film resistors, are often smaller than you might expect. It used to be
that the difference between a 1/2W and a 1W resistor was obvious: the 1W was considerably larger. That
way of looking at things sometimes now no longer applies. Please be assured that all resistors supplied
with ANK Audio Kits are rated at least per the specified wattage: in some cases, a higher than specified
wattage may be supplied.
1.6.4 Capacitor Manufacturers and Voltage Ratings
Occasionally, depending on parts availability, we may use capacitors from different manufacturers.
These will always be of equal or higher quality! As a result, some of the pictures in the manual may look
a bit different at times. With regard to voltage ratings, normally, the voltage rating of the supplied
capacitors will be exactly what you see on the parts lists. Occasionally, a part may be supplied with a
higher voltage. Think nothing of it!
1.6.5 Electrolytic Capacitors
For those who have not built a piece of electronics before, here is a little lesson on capacitors. There are
basically two types of capacitors that we use in the kits: electrolytic and signal capacitors. Of these,
electrolytic capacitors require special attention. Electrolytic capacitors are “polarized,” which means
they have a POSITIVE (+) and a NEGATIVE (–) lead and typically have values like 100uf 450V, 10uf 160V,
or 470uf 35V. These capacitors need to be installed correctly or else they will possibly blow up at some
point!
Each electrolytic capacitor will have a wide stripe on the NEGATIVE side. Always ensure that this stripe
(NEGATIVE) is positioned correctly. There are several keys on a printed circuit board to help you to know
how to position the capacitor:
1. There may be a "+" on the board indicating where to position the POSITIVE lead.
2. The segmented half of the circular stencil on the board shows where to position the NEGATIVE
lead. The unsegmented ('half-moon') part of the circle is where the POSITIVE lead goes.
3. The POSITIVE lead goes to a square solder pad while the NEGATIVE lead goes to a round solder
pad.
1.6.6 Diodes
When installing diodes note that they are oriented with a stripe — match the stripe on the diode with the
banding (||) stencil on the board.
1.6.7 Hardware/Mechanical
Not all of us are mechanically oriented. So, the kit is well laid out such that all the hardware is provided
and bagged in individual sections, so things should make sense. Start thinking mechanically because
about a third of the kit is mechanical. The first thing to remember is that good hardware is beautiful: we

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use all stainless steel metric hardware in the kits. It truly is a thing of beauty: don’t rush your
hardware! Here are a few helpful things to understand:
We use British metric hardware (M3, M4, M5, screw size 10mm, 15mm, etc..) as opposed to the
American imperial system (5/1000th or 50/1000th, 1 inch, 3/4 inch). Please familiarize yourself
with the hardware in the kit.
The screws will be called M3 or M4, which is the diameter of the shaft. The length of the shaft
will be in millimeters, so you will encounter things like an M4 screw 16mm, a PAN head screw
(which is a round spherical head), or a COUNTERSUNK or FLAT head screw (a screw head that
needs to be flush with a surface —for example, under a transformer). So if you are asked to use
an M3 16mm CSK screw, this is an M3 size (obviously), which is a thinner shaft diameter than an
M4; 16mm is the length of the shaft; and the head type is CSK, which is a countersunk or flat head
screw.
Once you have the screws mastered, look at the matching nuts such as M4 nut or M3 nut and
corresponding washers.
Standoffs are common in the kits (again, they are either M3 or M4 size, with different lengths).
They are typically threaded, so the screw goes into them.
If any of the hardware is confusing or something is not fitting right, please email us.
1.6.8 Wire Stripping and Tinning
When it comes to wires, we typically use 18 gauge (thicker) and 22 gauge in the kits. It's PTFE: Teflon
silver-plated copper wire. Basically this is classed as hook-up wire; we typically twist wire for you when
it needs to be. The other wire we use is called shielded cable, like an AN-A (Audio Note (UK)) for signals.
This is two-conductor wire: one is for the signal and the other (a big ground braid wrapped around the
signal wire) is the shielding, which helps prevent the cable from picking up noise. You should practice
stripping some 18g or 22g wire, and then try tinning this wire; this is the process of adding solder to the
bare wire so that the invisible coating on the wire is burned off. This makes for easy soldering to a PCB,
an RCA connector, or a transformer terminal. So it's a good idea to practice this a little before starting
the kit.
1.6.9 Wire Color
In the earlier sections of this manual, particularly those sections dealing with the Mains transformer
and Choke wires, the colors of the wires should match the color of the wires in your kit. If they don't, or if
you're unsure about things, contact audionoteki[email protected]. Later on, at the Interwiring stage, there
may be some differences between the descriptions (or pictures) of the color of wires that you will
connect and the color of the wires supplied with your kit; for example, depending on inventory, we may
supply a Black–Red twisted pair instead of a Green–Red (or vice-versa). Don't worry! Just be sure to
check the wiring diagrams carefully and connect the correct points together and all will be well!

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1.6.10 Optional Finishing Touches
From time to time we get asked about some of the build details of the ANK Finished Products that you can
see in the pictures in the "Assembled Kits Gallery!" (https://ankits.smugmug.com/) on our website. It's
important to understand that these stunningly beautiful products were done by an accomplished
professional builder with decades of experience and that some particulars of the build may be beyond
most of us. However, experienced builders who want to incorporate some of these finishing touches
should feel free to do so. While we don't officially support or supply parts for these optional
enhancements, there's no reason why you couldn't or shouldn't do them if you want to and feel that you
can handle them. Without getting into the details (you're on your own here), what you'll want to get hold
of are: heatshrink (to bundle wires), cable ties (to secure large capacitors), stacked (male/female)
standoffs and cable clamps (to elevate and secure signal cables), and cable sleeving. You can get some of
these from your local hardware store (for example, 1/4" Cable Clamps) and other, more specialized,
parts from online distributors such as Grainger, Digi-Key, Mouser, or Cable Ties and More. If you do
decide to dress your build with some of these, please send us a picture or two. We'd love to see what you
did!
1.7 Build Process
1.7.1 Some Good Rules of Thumb for Building Your Amplifier
Take your time, prepare yourself and try and work on a small task each time you start
to build the kit.
Instead of rushing through a second section –use the end of the session time to check
your work. Always ask yourself if the step you are performing makes sense.
Have fun with your build –savour the build experience –take an extra bit of time to
really do a good job!
Feel free to contact us via email [e-mail] if you have any questions
or suggestions during your build –feel free to send us pics, etc. –and we can give you
tips along the way.
Good luck!

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1.7.2 Organization of this Manual
We have divided the build up into the following sections:
Section 1 Introduction
Section 2 Feet, IEC and Rocker Switch Installation
Section 3 Mains Transformer installation
Section 4 IEC PCB Installation
Section 5 Choke installation
Section 6 Power Supply PCB Installation
Section 7 ECF80/EL34 PCB Installation
Section 8 Speaker Posts, RCA Jacks Installation
Section 9 Output Transformers Installation
Section 10 Interwiring
Section 11 Testing
Section 12 Finishing Touches
Section 13 Congratulations and Final Thoughts
Appendix

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Here's another way of looking at how the manual is organized and how the sections fit into the
'big picture': the main sections are mapped so that they mirror how the components will be
positioned in the amplifier chassis:

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1.7.3 Electrical Safety Warning
Please be aware of proper electrical safety.
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 contact ANK Audio Kits via phone or email ([e-mail])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
Feet, IEC and Rocker Switch Installation
2.1 Overview
In this and the following three sections we will install the feet, IEC socket and PCB, rocker
switch, Mains Transformer, and the Choke, as well as make the important initial connections
to the Mains transformer.

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2.2 Feet Installation
Our first task is to install the 4 rubber feet into the holes in the 4 corners of the chassis –using
the provided hardware in the “Feet” bag in the big Hardware bag. Use an M4 screw along with
the big washer on the outside of the foot and then a M4 nut and M4 black serrated washer
against the chassis on the inside of the chassis!
Might be handy to use an M4 nut driver or something similar to tighten the nuts for the feet on
the inside of the chassis! Now you are ready to go!

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2.3 IEC and Rocker Switch Installation
Let's install the input AC receptacle (IEC plug) and rocker switch in the rear of the chassis.
Here you can see the correct installation of the IEC plug in the rear of the chassis along with the
rocker switch.

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Section 3
Mains Transformer Installation
3.1 Mains Transformer Installation
Let's position the Mains transformer now. It uses 2 rubber strips to isolate it from the chassis.
Lay down the two rubber strips so that they are over the correct holes in the chassis –these
holes are about 100mm apart from each –then place the Mains transformer carefully over
top –the Primary of the Mains transformer (2 Black + 2 White + 1 Green wire) is placed
towards the back of the chassis while the Secondary wires are placed towards the front.
The provided hardware in the bag marked “Mains transformer” will be used to secure down the
Mains transformer. Prior to securing the transformer in place we will hook up the IEC section
and PCB with the provided parts and cables found in the “IEC” bag.