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L4 EL34p Power Amplifier 

 

 

 

 

Construction Manual 

 Version 1.14, June 2019 

 

audionotekits@rogers.com 

1-613-822-7188 

 

    

    

 

 

 

 

Summary of Contents for L4 EL34p

Page 1: ...L4 EL34p Power Amplifier Construction Manual Version 1 14 June 2019 audionotekits rogers com 1 613 822 7188...

Page 2: ...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 Touc...

Page 3: ...g the Power Supply PCB 29 6 4 Mounting the Power Supply PCB 30 Section 7 ECF80 EL34 PCB Installation 7 1 Overview 31 7 2 Building the ECF80 EL34 PCB 32 7 2 1 Resistor Installation 33 7 2 2 Capacitor I...

Page 4: ...t 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...

Page 5: ...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 divide...

Page 6: ...arnest 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 i...

Page 7: ...ics 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...

Page 8: ...ifier Please remember if you have any questions please don t hesitate to contact audionotekits rogers com Above you can see the general layout of the amplifier this includes starting from top right an...

Page 9: ...lifier 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 an...

Page 10: ...d 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 sold...

Page 11: ...s 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...

Page 12: ...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 w...

Page 13: ...tshrink 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...

Page 14: ...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 Install...

Page 15: ...audionotekits rogers com Page 15 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 com...

Page 16: ...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...

Page 17: ...Page 17 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 Chok...

Page 18: ...he 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 again...

Page 19: ...rogers com Page 19 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...

Page 20: ...les 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 t...

Page 21: ...1 IEC PCB Wiring The IEC PCB makes wiring the Mains transformer for your world voltage a little easier it is mounted on the rear of the chassis in a horizontal position above and to the left of the IE...

Page 22: ...Copyright 2019 AudioNote Kits www AudioNoteKits com audionotekits rogers com Page 22 Connect the four Primary wires as shown The wiring is the same for both 120V and 240V systems...

Page 23: ...Complete the wiring for the rocker switch IEC and grounds as shown Be sure to allow sufficient length for all wires it s a good idea to lay it all out first before cutting the wires to the appropriat...

Page 24: ...omplete the wiring for the rocker switch IEC and grounds as shown Be sure to allow sufficient length for all wires it s a good idea to lay it all out first before cutting the wires to the appropriate...

Page 25: ...eel off the paper covering on the plastic insulating board then using the IEC hardware mount the IEC PCB to the back of the amplifier as shown in the picture below use 2 standoffs then the PCB 2 more...

Page 26: ...Copyright 2019 AudioNote Kits www AudioNoteKits com audionotekits rogers com Page 26 Time for a break...

Page 27: ...rogers com Page 27 Section 5 Choke Installation 5 1 Choke Installation Install the large Choke called the CH 100W which you will see marked on the underside of the unit Note that the 2 black wires exi...

Page 28: ...AudioNote Kits www AudioNoteKits com audionotekits rogers com Page 28 Section 6 Power Supply PCB Installation 6 1 Overview In this section we ll be building the Power Supply board which is situated ne...

Page 29: ...ual or on your disk Take your time and take a break from time to time While it s not necessary you can solder through hole resistors on the top as well as the bottom if you prefer But don t use to muc...

Page 30: ...nstall the four standoffs onto the board from the hardware bags position it as shown in the Choke Installation section above and secure to the bottom of the chassis with M4 10mm screws If your kit is...

Page 31: ...on 7 1 Overview This is the large PCB that we will start to populate and verify Quite a bit of work but we can take it one step at a time We will divide up the board into several sections and take our...

Page 32: ...om the underside of the board We suggest that you use just a little solder to secure each pin to the board perhaps just start with two pins which are opposite to each other to make sure the base stays...

Page 33: ...1 R4 2 100K 1W 2 R5 1 R5 2 470R 1 2W 2 R6 1 R6 2 100R 1 2W 2 R7 1 R7 2 33K 1 2W 2 R8 1 R8 2 33K 1 2W 2 R9 1 R9 2 22K 1 2W 2 R10 1 R10 2 270K 1 2W 2 R11 1 R11 2 270K 1W 2 R12 1 R12 2 10K 1 2W 2 R13 1...

Page 34: ...code reading from left to right so that all resistors will be reading in the same direction It makes it easier for any future debugging or for recognizing resistors in correct positions Once resistor...

Page 35: ...side foil 7 3 Final Assembly of the ECF80 EL34 PCB Now you can install the valve bases For the 8 pin sockets be sure to match the notch on the valve base with the PCB Take your time soldering on the u...

Page 36: ...of the chassis let s install the speaker posts and RCA jacks The two RCA jacks install into one of the three pairs of vertically aligned holes We ll plug up the other 2 pairs later Orient the ground...

Page 37: ...d the tinned Ground lead against the tinned Ground tab on the RCA and apply heat it will usually adhere immediately Now have a look at the yellow dual shielded cable One end has Red and White wires an...

Page 38: ...ion 9 1 Output Transformers Installation The IE core transformers install with the Red Black and Yellow wires facing the ECF80 EL34 PCB The build below positions is for the integrated amp but the tran...

Page 39: ...one side you will see Red Black and Yellow dots and lugs On the other you will see Green larger Blue smaller in the middle and Purple larger Orient the transformers so that the Red Yellow and Black lu...

Page 40: ...ight points together and check the chart at the end of the Interwiring section and all will be well Using the wire from the OP Transformer bag prepare the following wires 2 Black wires of approximatel...

Page 41: ...e Output Transformers with the supplied hardware For each transformer Solder the 7 wire from the Black speaker post to the Green lug on the transformer Solder the 7 wire from the middle Red speaker po...

Page 42: ...Copyright 2019 AudioNote Kits www AudioNoteKits com audionotekits rogers com Page 42 Definitely time for another cup before we do the Interwiring...

Page 43: ...of the kit build and we can now look at hooking everything up together this is considered the INTERWIRING STAGE This guide explains the interwiring best to look at the higher resolution version of the...

Page 44: ...is will go in the next section to the ECF80 EL34 PCB B BE SURE TO MAKE THIS MORE THAN LONG ENOUGH Connect one end of a Green wire to the Power Supply GND This will go in the next section to the ECF80...

Page 45: ...urple 6V3 3A AND LOOP OUT either lugs CT 6V3 Red Blue White 6V3 6A either Brown Black Green 6V3 6A either 10 4 Output Transformers Interwiring Looking at the slide at the beginning of this section mak...

Page 46: ...A jack Left Output Transformer Left Side of ECF80 EL34 PCB Right Channel Lower RCA jack Right Output Transformer Right Side of ECF80 EL34 PCB Looking at the slide at the beginning of this section On t...

Page 47: ...eginning of this section The LED holder is attached to the front panel with a little adhesive and the LED is wired to the ECF80 EL34 PCB LED PL either way Now use the Interwiring Chart on the next pag...

Page 48: ...CF80 EL34 PCB GND ECF80 EL34 PCB B Red wire to PS PCB B as above GND beside B A1 left A2 left A1 right Green wire to PS PCB GND as above Black wire to OP 390 Left Red wire to OP 390 Left Black wire to...

Page 49: ...rst thing to do is to check and check and check again your work No need to insert any tubes at this point Let s go through a series of ohm checks to make sure the amp is more or less constructed corre...

Page 50: ...traight connection between this point in the amp and another point 11 1 1 Mains Fuse Installation Install the fuse in the small plastic fuse holder and insert it into the IEC If you are operating in 1...

Page 51: ...on both channels on the ECF80 EL34 PCB with respect to ground you should see 366V this is the Output Transformer 11 2 Install the Tubes Install the tubes and power on again If everything is OK and no...

Page 52: ...then power on the amp and play an audio CD test through the amp Adjust the volume to halfway and measure the AC voltage across the 8 ohm resistors you should be able to adjust the volume and see the v...

Page 53: ...ion 12 Finishing Touches 12 1 Installing the Front Faceplate Remove the protective films from the front and back of the front faceplate Install the front faceplate using four Black M4 CSK flat head sc...

Page 54: ...F80 and EL34 positions will allow you to tailor the sound to your specific preferences The ECF80 triode pentode can be substituted by readily available NOS 6BL8 and E80CF 7643 tubes and there are many...

Page 55: ...x 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...

Page 56: ...19 AudioNote Kits www AudioNoteKits com audionotekits rogers com Page 56 Resistor Color Code Reference You can also find an Interactive Resistor Color Code Calculator on our website available from the...

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