Related Manuals for Audio Note EL34
Summary of Contents for Audio Note EL34
- Page 1 Manual Version 1.1 - August 2009 Copyright © 2006-2009 AudioNote Kits Page 1 www.AudioNoteKits.com audionotekits@rogers.com...
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Page 2: Table Of Contents
Section 8: EL34 Board Filament Hook-Up ..........................31 Section 9: EL34 Board To Output Transformer Wiring ......................33 Section 10: HT and GND Connections to EL34 Board ......................35 Section 11: Speaker Post Connections ..........................37 Section 12: Driver Board Filament Hook-up ......................... 41 Section 13: ECF80 to EL34 Board Interconnections ...................... -
Page 3: Section1: Introduction
Section1: Introduction Thanks for purchasing the AudioNote L4 Series EL34 Push-Pull Power Amplifier. 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. -
Page 4: Component Placement Breakdown
Component Placement Breakdown Copyright © 2006-2009 AudioNote Kits Page 4 www.AudioNoteKits.com audionotekits@rogers.com... -
Page 5: Electrical Safety Warning
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. -
Page 6: Section 2: First Steps
Section 2: First Steps In this beginning section we will start by installing the 4 feet then we will install the Mains transformer and wire up the IEC section. Installing the feet 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”... -
Page 7: Iec Section Installation
IEC Section Installation Let’s install the input AC receptacle and rocker switch known as the IEC socket & Rocker in the rear of the chassis. Shown opposite is the rocker switch slot above the fitted IEC socket. Here you can see the correct installation of the IEC plug in the rear of the chassis along with the Rocker switch. -
Page 8: Iec Section
Place the Mains transformer carefully over top. Note that the primary of the Mains transformers (2 black + 2 white + 1 green wire) is placed towards the back chassis while Secondaries are placed towards the front. The provided Hardware in the bag marked “Mains transformer”... - Page 9 Remember, the following example shows how to wire for 120v operation only. If you live in a 120V AC world voltage then we will twist the black wires together as shown as well as twisting the white wires. We will also be working with the green screen wire.
- Page 10 Now let’s deal with the green wire coming out of the Mains Primary. This is the ground lead that we will be attaching to chassis ground. Strip the wire and tin it and then solder the ground lug to it. This is where you will attach the earth wire to.
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Page 11: Preparing The Secondary Leads
The IEC section is now complete. The picture opposite shows the completed wiring for 120v operation. * Applies to 120v operation only. Preparing the Secondary leads Pull out your insert sheet showing the Mains transformer windings for the secondary. The first step is to twist the wires according to the windings: Blue &... -
Page 12: Section 3: Power Supply Board Construction
Section 3: Power Supply Board Construction Here are the parts for the Power Supply Board along with the spacer hardware. Quantity Description 1,000v 3A fast Diodes 220uF 450v Electrolytic Capacitors 330K 1W resistor 1M5 1W resistor Installing the Components IMPORTANT: The Diodes that we are using have a stripe on one side that you need to match with the PCB. - Page 13 The next job is to install the Electrolytic Capacitors. Quick Lesson on Electrolytic Capacitors These capacitors have a Positive and Negative side to them and need to be installed correctly or they will BLOW up! The Stripe on the side of the capacitor can designates the NEGATIVE side.
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Page 14: Section 4: Choke Installation And Ht Wiring
Section 4: Choke Installation and HT Wiring Here is how the choke and the Power supply board will be positioned in the chassis. You will want to bring the Mains transformer secondary leads through on this side of the chassis and position the twisted filament wires from the secondary windings going the other way into the amplifier. - Page 15 Finally, bring the triple braided wire down the length of the chassis for later use. Now we can move onto the next stage of the build. Copyright © 2006-2009 AudioNote Kits Page 15 www.AudioNoteKits.com audionotekits@rogers.com...
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Page 16: Section 5: Ecf80 Driver Board Construction
Section 5: ECF80 Driver Board Construction In this section we will be building the first of the 2 Driver Boards, which contain the ECF80 tube. See the Appendix for the schematic for this board. The build of this board is quite straightforward and shouldn’t pose any problems. Just make sure that the three electrolytic capacitors are inserted the correct way around - observing correct polarity. -
Page 17: Parts List
100K 330K 470K R10, R11 1.8K R4a, R4b Capacitors 470uF 16v ECF80 cathode 10uF 450v ECF80 100uF 450v HT / GND .22uF 630v Input to EL34 100pF 630v ECF80 input 820pF Copyright © 2006-2009 AudioNote Kits Page 17 www.AudioNoteKits.com audionotekits@rogers.com... -
Page 18: Installing The Spacers And Valve Base
Here is a reference picture of the unpopulated board. To begin construction you will need the following hardware parts: Installing the Spacers and Valve Base Install the 5 spacers and secure them into position. Using the M3 16mm screws, spacers and M3 nuts, you can secure the valve base into position on the board. -
Page 19: Installing The Resistors
Installing the Resistors Install the resistors into their correct positions on the board. Refer to the parts list on the previous page. It’s also a good idea to use an OHM meter and refer to the color code chart for inserting the correct resistors into position. NOTE: In the picture opposite we have also installed the 2 x .22 film caps into position –... -
Page 20: Installing The Capacitors
Installing the Capacitors First, install the two large .22uF film capacitors at the top and bottom of the board. Next, install the 100uf electrolytic capacitor. You will see the stripe on the side of the capacitor that denotes the negative side (just like we did on the power supply board) and you will see the + sign on the PCB on the positive side of the capacitor. - Page 21 Finally, insert the 470uF 16v electrolytic capacitor into its position (follow the same rules of Negative Stripe position). That Basically completes the ECF80 driver board - You will need to build another one now for the other channel! See below how they will be positioned in the chassis. Well done to get to this point –...
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Page 22: Section 6: El34 Hardwired Section
In this section we will be building the hardwired section on the aluminum plates where EL34’s reside – It’s a challenging little section but also fun and rewarding. Here is what It will look like from the topside. The picture below shows what the boards will be like from underside: NOTE: Since these pictures were taken, we have relocated 2x 10K resistors from the Driver Board to here. -
Page 23: Parts List
Parts List Quantity Value Description Resistors 250R 470R 1W (may not be shown in some pictures in this section) Capacitors 47pF Silver Mica 220uF 100v ELECTROL Here is a picture of the parts that we will be using in this section. - Page 24 Position the 2x 250 ohm resistors on the board over the holes as shown. Use the supplied hardware to secure the resistors into position. Note that the nuts will be on the underside of the board. Install the supplied 'Tag Strip' into position on the underside of the board.
- Page 25 Install the two 10R resistors into position. The trick here is to route the 10 ohm red resistor through to the 250 ohm resistor as shown. Curl the leads around for good mechanical connection then solder into position and cut the remaining leg off.
- Page 26 Start by taking the Negative side of the capacitor (stripe side) and bend the leg into position and thread it through the resistor hole. Then you can solder the resistor and the capacitor leg and the stranded wire together – be careful not to burn the casing the capacitor.
- Page 27 Now you can install the 47pf capacitor into position – refer to the graphic. On the graphic we have 12 positions on the tag strip – make sure to align correct position with your connections (in this case the 47pf cap connects to position 11).
- Page 28 – the power supply will supply 6.3V AC voltage to this board via the tag strip and this will connect to pins 2 & 7 of each EL34 – Lets start this wiring by “paralleling” the pins 2 & 7 of the two valve bases.
- Page 29 Then you can twist these wires slightly and connect to pins 2 & 7 of the right EL34 valve base. Congratulations! Well done if you have made it this far. You will have to repeat this whole board build for the other channel but I think a good nights sleep is in order! Copyright ©...
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Page 30: Section 7: Layout Recap
ECF80 driver boards installed into the chassis – no need to secure any of these boards as we will be wiring underneath them later on. In the next picture we have positioned EL34 Hardwire Boards into position – note that the tag strip is closest to the ECF80 driver board. -
Page 31: Section 8: El34 Board Filament Hook-Up
Section 8: EL34 Board Filament Hook-Up Now that we have nicely completed out EL34 hardwired boards we have to make some wiring connection to these boards. Lay the boards out as shown in the pictures opposite – also lay down the two 6.3V filament supply twisted pairs... - Page 32 Repeat the step for the outer hardwired board- as shown opposite. Well done on completing the FILAMENT wiring section. Copyright © 2006-2009 AudioNote Kits Page 32 www.AudioNoteKits.com audionotekits@rogers.com...
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Page 33: Section 9: El34 Board To Output Transformer Wiring
Section 9: EL34 Board To Output Transformer Wiring In this section we have to hook up the red and black wires from the Output transformer primary’ into the EL34 Hardwired section. On the diagram opposite, look at the connections on pin 3 of each valve. - Page 34 Strip the ends of the red and black twisted and then tin the end of the wires. Connect the wires to their corresponding Pin 3 on each valve base. Please stick to the color-coding so that the 2 channels don’t end up out of phase with each other! Repeat the connection of the red black twisted from the output transformers for the other channel.
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Page 35: Section 10: Ht And Gnd Connections To El34 Board
Section 10: HT and GND Connections to EL34 Board Before continuing, it would be a good idea to pull out the General Wiring Diagram from the Appndix. Take two lengths of RED 18 gauge 600v wire and strip the ends. - Page 36 Now do the same thing but with 2 black wires – these will be the High Voltage Grounds. Wire these into PGND_A & PGND_B. That completes the high voltage wiring! Copyright © 2006-2009 AudioNote Kits Page 36 www.AudioNoteKits.com audionotekits@rogers.com...
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Page 37: Section 11: Speaker Post Connections
Section 11: Speaker Post Connections Move the output transformers out of the way a little so we can install speaker posts in the rear of the chassis. We are going to install the 3 speaker posts that go in the rear of the chassis. Locate the 3 holes that are in a row. - Page 38 If you check the EL34 schematic you will see that we have a 10R resistor and a .1 cap in series between the GND and the 8ohm speaker post. This is used in push pull amplifiers as a filtering circuit.
- Page 39 Well done – now lets complete the wiring of the twisted yellow and black on the other end... Take the yellow black wire and trim the ends. Position your EL34 board as shown and route the wire under the board. Copyright © 2006-2009 AudioNote Kits Page 39 www.AudioNoteKits.com...
- Page 40 Solder the yellow wire into TAG position 1 – this is beside the filament – remember you are looking at the board upside down. We will be connecting to that same terminal later from the Driver Board. Wire the black wire from the twisted yellow black into the PGND position 6 7 or 8 –...
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Page 41: Section 12: Driver Board Filament Hook-Up
EXPLANATION: The filament wiring is basically AC right off the Mains secondary – these filament wires go to the EL34 hardwired board and then connect down to the ECF80 board for each channel. In order to have a very quiet amplifier, however, we need to have the AC voltage 6.3V raised up about 30V DC –... - Page 42 Where the orange wire (from FIL_DC) connects to the ECF80 board you need to add another orange wire to connect over to the FIL on the other ECF80 board. To summarize: The orange wire from FIL_DC connects over to the first ECF80 board and then continues on through a second orange wire over to the second ECF80 board –...
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Page 43: Section 13: Ecf80 To El34 Board Interconnections
Section 13: ECF80 to EL34 Board Interconnections We are now going to make the connections between the hardwire board and the ECF80 driver board. Here is a graphic showing the tag positions on the hardwire board looking from the topside now along with the connections that you are going to be making in this section. - Page 44 With the inter-wiring complete you can secure down the Hardwired EL34 board to the chassis and then secure the ECF80 board into position also. Well done – we have completed a channel.
- Page 45 .5 ohms or 1 ohm also. Now lets go make our first real ohm check... I am checking between pin 5 of the EL34 valve base, which is connected to - OUT and the ECF80 -OUT connection – reading 4 ohms.
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Page 46: Section 14: Rca Connections And Final Earth
Section 14: RCA Connections and Final Earth One of our last steps now is to install the input AN-A cable – this is the shielded cable that will take the input audio signal into the ECF80 driver boards. The first step is to install the two RCA posts in the back of the unit - making sure that they do not short to the chassis. - Page 47 The cable should be laid down the center of the amplifier as shown here. The ends will connect to their associated Driver Board - make sure that the Left input goes to the Left driver board (and similar for the Right channel). Here you can see the AN-A cable connected to the ECF80 board.
- Page 48 Now it’s safe to say that you have completed all the wiring for the L4 Amplifier - Congratulations! Copyright © 2006-2009 AudioNote Kits Page 48 www.AudioNoteKits.com audionotekits@rogers.com...
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Page 49: Section 15: Powering On And Testing
Section 15: Powering On and Testing Installing the FUSE – Pull out the fuse drawer and flip it over – then push in the fuse into position and insert back in the IEC receptacle. The switch position above shows the unit OFF – when the 1 is pressed flush with the chassis the unit will turn ON. Power On Procedure If you have a Variac we will take advantage of it –... -
Page 50: Appendix
Appendix The appendix contains auxiliary information. That is information that is either common to most project manuals or any last minute pieces of information that did not make it into the manual in time. It may also contain pull-out circuit diagrams that may be handy to have outside the manual etc. -
Page 51: Resistor Color Code Reference
Resistor Color Code Reference You can also find an 'Interactive Resistor Color Code Calculator' on our website (available from the Links page). Copyright © 2006-2009 AudioNote Kits Page 51 www.AudioNoteKits.com audionotekits@rogers.com... -
Page 52: Mains Transformer Windings Diagram
Mains Transformer Windings Diagram Copyright © 2006-2009 AudioNote Kits Page 52 www.AudioNoteKits.com audionotekits@rogers.com... -
Page 53: Power Supply Board Schematic
Power Supply Board Schematic Copyright © 2006-2009 AudioNote Kits Page 53 www.AudioNoteKits.com audionotekits@rogers.com... -
Page 54: Driver Board Schematic
Driver Board Schematic Copyright © 2006-2009 AudioNote Kits Page 54 www.AudioNoteKits.com audionotekits@rogers.com... -
Page 55: Output Board Schematic
Output Board Schematic Copyright © 2006-2009 AudioNote Kits Page 55 www.AudioNoteKits.com audionotekits@rogers.com... -
Page 56: Output Section Hardwiring Diagram
Output Section Hardwiring Diagram Copyright © 2006-2009 AudioNote Kits Page 56 www.AudioNoteKits.com audionotekits@rogers.com... -
Page 57: General Wiring Diagram
General Wiring Diagram Copyright © 2006-2009 AudioNote Kits Page 57 www.AudioNoteKits.com audionotekits@rogers.com... -
Page 58: Full Schematic
Full Schematic Copyright © 2006-2009 AudioNote Kits Page 58 www.AudioNoteKits.com audionotekits@rogers.com...