ANK Legend Monoblock 300B-2A3 Construction Manual

Parallel set amplifier

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Legend Monoblock 300B–2A3

Parallel SET Amplifier

Construction Manual

Version 3.04, October 2019

audionotekits@rogers.com

1-613-822-7188

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Page 1 Legend Monoblock 300B–2A3 Parallel SET Amplifier Construction Manual Version 3.04, October 2019 audionotekits@rogers.com 1-613-822-7188...
Page 2: Table Of Contents
Installing the Choke ……………….........…………........…………… Installing the IEC and Rocker Switch …....…………........…………… Section 3 — The Transformers ................. … Overview ………………………………………………………………………………...…..….………..…….…… Installing the Mains Transformer ………………………………………….…..….………..…….…… Installing the Output Transformer ……………………………………..….………………..…….…… Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 2...
Page 3 Overview ……………………………………………………………..……………………..….………..…….…… Installing the RCA Input Jack …………………………………..……....…..….………..…….…… Wiring the RCA Input Jack …………………………………..……....…..….………..…….…… Mounting the Front Insert Plate ……………………......……………………………..…….…… Installing the Speaker Posts ……………………......……………………………..…….…… Wiring the Speaker Posts ……………………......……………………………..…….…… Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 3...
Page 4 11.4 Tube Rolling ……………………..…………….…………….…………………………………………….…...………… 11.4.1 5U4-G ………..………………………….……..……….……………………..……………………...…………… 11.4.2 6SH7 ……………………..…………….……..……….……………………..……………………...…………… 11.4.3 300B and 2A3 ……………………..……………………………………………………….…….…………… 11.5 Thanks ……………………..…………………………………………………..……………….………….………………….… Appendix ……………………………………………..……………………………………………………...……….……….…… Resistor Color Code Reference …………….……………………………………………………….…..…….…… Mains Wiring for 240V ……………………….…………………………………………….…..………………….…… Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 4...
Page 5: Section 1 - Introduction
Section 1 Introduction Thanks for purchasing the ANK Audio Kits Legend Monoblock 300B-2A3 Parallel SET Amplifier. Our goal is to provide you with the highest quality kit that you will build from scratch with these instructions. This is very high end and sophisticated piece of audio equipment that will surely become a showpiece of your sound system.
Page 6: About Ank Audio Kits
As a result, ANK Audio Kits began offering this service for some 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.
Page 7: Basic Operation Of The Amplifier
ANK Audio Kits and SET amplifiers go a long way back, right to the beginning in fact, with our Kit1 300B, which has had successive and successful anniversary editions. It's no surprise then that these 300B Single and Parallel SET monoblocks are simply awesome! A pair of these power amplifiers are a perfect mate for the Mentor pre-amplifier and a path to truly exceptional audio enjoyment.
Page 9: Schematic
From time to time revisions and upgrades to products result in circuit changes that are not always reflected in manuals. If you encounter any issues with how this schematic relates to your build that need clarifying, contact us at audionotekits@rogers.com. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 9...
Page 10: Equipment
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! For example, WBT-0800. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 10...
Page 11: Components
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.
Page 12: Diodes
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. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 13: Wire Color
1.5.10 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.
Page 14: Build Process
4. The Power Supply 5. The Filament Supply Board 6. Front Insert Plate 7. The IO Connections 8. Wiring Check Lists 9. Testing 10. Finishing Touches 11. Final Thoughts Appendix Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 14...
Page 16: 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 contact ANK Audio Kits via phone or email (audionotekits@rogers.com) 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 17: Section 2 - Mechanical Assembly
Let's start with the chassis and install the:  rubber grommets  8-pin valve base  Tang strips  Capacitor clamp  Ceramic Hardwiring Posts  Filament Supply board hardware  Choke Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 17...
Page 19: Installing The Valve Base
. This view Use the Black ring on the underside of the chassis to secure the valve base into position clearly shows the notch pointing toward the front of the chassis. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 19...
Page 21: Installing The Tang Strips
Position the Tang strips as shown and secure them with Black M3 10mm screws and nuts (on the underside of the chassis). Don’t screw them too tight as they can be tightened later; keep them loose to start. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 23: Installing The Capacitor Clamp
Next let's install the capacitor clamp. Install the capacitor clamp on the underside of chassis with the countersunk Black screws and nuts. The clamp mounted on the inside of the chassis Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 23...
Page 25: Installing The Ceramic Hardwiring Posts
We are now going to install the 12-position and 7-position ceramic hardwiring posts: Position the hardwiring posts in the chassis as shown below, then secure them with 6mm Silver M3 countersunk screws from the top side of the chassis. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 27: Installing The Filament Supply Board Hardware
In this part we will install the standoffs to prepare for the Filament Supply board installation. Install 4 M3 10mm hex standoffs in the chassis as shown below and secure them with silver M3 6mm countersunk screws from the top side of the chassis. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 28 Filament Supply board away for installation later, when it has been completed and the wiring that will connect it to the Mains Secondary and the 300B valve bases has been done. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 29: Installing The Choke
Use the 4 M4 countersunk screws and install the Choke from the top of the chassis, securing it with washers and nuts on the inside of the chassis. The view from above showing the 4 screws holding the Choke Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 30: Installing The Iec And Rocker Switch
Install the Rocker Switch, which just snaps into position. Use M3 10mm CSK screws to Install the IEC socket. Inside chassis view of installed Rocker Switch and IEC socket Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 30...
Page 32: Section 3 - The Transformers
 OP-305 PSE 300B Output transformer It's a good idea to read through this whole section prior to starting to so you have a good idea of what is coming! Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 32...
Page 33: Installing The Mains Transformer
Let's start with the T-195 Mains transformer. This transformer has a Primary consisting of 5 wires (2 White, 2 Black, and 1 Green) and a Secondary consisting of 13 wires (a number of colors, as shown below). Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 34 WD-40 so that they can slide through the grommet holes a little easier. Once all the wires are fed through you can use a cloth to wipe off any excess WD-40 spray. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 35 Lay the transformer down and feed the Primary wires through the single grommet and the Secondary wires through the two grommets, as shown above. Lay down the rubber strips under the Mains transformer as shown below — take your time and be patient. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 35...
Page 36 Once the transformer is mounted on the chassis then put an M4 16mm screw into position and secure one corner of the transformer; keep it loose and continue to position the transformer so that the other screws will line up correctly. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 37 Once the transformer is mounted on the chassis then put an M4 16mm screw into position and secure one corner of the transformer; keep it loose and continue to position the transformer so that the other screws will line up correctly. Primary side Secondary side Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 37...
Page 38: Installing The Output Transformer
Once the Mains transformer is positioned and secured we can install the much easier Output transformer. For the Parallel 300B/2A3 we use the OP-305 transformer and for the Single 300B/2A3 we use the OP-300 transformer. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 39 Primary (the Red and Black wires) is closest to the Front Insert Plate. Here's a view of the underside showing the transformer wires coming through the chassis. Phew! Congratulations on completing the Transformer installation section. Another cup? Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 39...
Page 40: Section 4 - The Power Supply
15K resistor, and another 100uf capacitor. The voltage after the Choke is sent directly to the Output transformer Primary to provide the B+ for the 300B tube and the voltage after the 15K resistor (C) is the B+ for the 6SH7 tube. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 42: Installing The Chassis-Mounted Capacitor
Installing the Chassis-Mounted Capacitor Install the 35mm capacitor clamp into position and secure with the supplied hardware. Position the 100+100uf capacitor as shown below: Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 42...
Page 43: Preparing The Chassis Ground
Add a lug to the tinned wire and then solder the lug onto the wire. Do this by adding solder through the front of the lug, as shown below. Referencing the following graphic: Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 44 We may be moving the wires a little later so there's no need to tighten it too much! Here you can see the 3 wires attached to the Chassis Ground. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 45: Wiring The Iec, Rocker Switch, And Mains Transformer
“takes” such that the solder is shiny and the wire has accepted the solder. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 46 Rocker Switch, as shown in the graphic above. Take the prepared Red/Black twisted cable and complete the connections as shown in the graphic. Leave about 5 inches of twisted White/White-Grey wire, at least. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 46...
Page 47: Installing The Resistors
As you can see in this schematic, we've labeled key points A, B, C, and D. This should help us keep our bearings. Have a look also at this graphic, which shows the job at hand. Note the points labeled A, B, C, and D. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 48 Thru 10K 2W Red wire to Black wire from One Black wire Output transformer resistor to 12- 12-position 100+100uf from Choke Primary position post C post B capacitor Positive Not connected Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 48...
Page 49 Not connected Not connected Not connected One end of 30uf Mundorf capacitor Green wire to top GND-D Position the resistors into the ceramic posts, as shown below, and solder the connections. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 49...
Page 50 Position and connect the 10uf electrolytic capacitor across the 47K resistor as shown above, with the NEGATIVE (wide stripe) lead connected to the third from the top GND-D on the 12-position post and the POSITIVE lead connected to the top CT on the 7-position post. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 52 Green or Black wire — or, for the adjacent jumpers, you can just use bare wire.) Have a look at an imaginative way to make a jumper, on the next page. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 53 You can even make a jumper by bending a resistor lead. Here's a picture of the 47K resistor bent in such a way as to make the jumper on the 7-position post: Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 54: Wiring The Chassis-Mounted Capacitor
Wiring the Chassis-Mounted Capacitor Referencing the following graphic: Take solid core Red and Black wire supplied in the wire bag and connect the 100+100uf capacitor into position as shown above and below. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 54...
Page 55 Install the 30uf Mundorf capacitor into position. This is a film cap so there is no polarity, but you may as well have the writing facing up towards you. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 56: Connecting The Choke
Connecting the Choke Referencing the following graphic: Connect the 2 wires coming from the Choke, as shown above and below. Either wire can go to either post. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 56...
Page 57: Initial Mains Secondary Wiring
12-position post. Connect the Yellow wire from the Mains Secondary to A on the 12-position post. Connect the Blue/White wire from the Mains Secondary to the bottom CT on the 7-position post. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 59: Power Supply To Front Insert Plate Wiring
Connect one end of the Red wire to C on the 12-position ceramic post, as shown above. Connect one end of the Black wire to the top GND-D on the 12-position ceramic post. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 60: Connecting The Output Transformer
The last connection that we'll make to the Power Supply is the Black wire from the Output transformer. This wire comes from the grommet near the front of the chassis by the Filament Supply board. Connect this Black wire to B on the 7-position ceramic post. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 60...
Page 61: Wiring The Rectifier Filaments
Position them out of the way — between the Choke and the side of the chassis, as shown below: Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 62 Congratulations! This completes the Power Supply section. Before you go any farther, we strongly recommend that you go back to the beginning of the Power Supply section, and check every connection carefully! Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 63: Section 5 - The Filament Supply Board
In this section we will be populating the Filament Supply PCB. This board will take the 7V AC voltages from the Mains Secondary and DC regulate them down to 5V which will be used to supply the 300B filaments. Filament Supply board Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 63...
Page 65: Parts List
10uf 16V Electrolytic Capacitors C5, C6 KBU6J Bridge Rectifiers B1, B2 LM1084 ADJ 5V Regulators IC1, IC2 300R Resistors R1, R3 100R Resistors R2, R4 Here are the parts ready for installation Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 65...
Page 66: Installing The Resistors
2–3 mm spacer: this will still let you solder while ensuring that the resistor is not pressing against the board. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 67: Installing The Capacitors
DC filament voltages. You'll see a notch on the Bridge Rectifier (part number: KBU6J): match the notch with the '+' (POSITIVE) stencil on the board. Install the 2 KBU6J Bridge Rectifiers at B1 and B2. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 68: Installing The Regulators
Insert the regulators and heatsinks into the board at IC1 and IC2 as shown in the picture below and on the next page. Note that they are oriented in the same direction. Solder the 3-pin regulator and the heatsinks from underneath the board. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 69 Congratulations! You've now completed the Filament Supply PCB. Before we install the board, we'll want to make the AC connections to it from the Mains transformer and prepare the DC connections for the Front Insert Plate. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 70: Connecting The Filament Supply Board
Take the Black wire, the Purple wire, the Black/Green wire, and the Green/Yellow wire and position them for the connections that we'll make. Cut the wires to the lengths needed, strip about 1/4" of insulation off the wires and tin them. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 71 Black wire to the AC-3 solder tab. Green/Yellow wire to the AC-4 solder tab. Here's what it looks like: Trim off the excess wires on the top of the board. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 71...
Page 72 4 M4 screws into the standoffs from the underside of the chassis. With that completed we can now move on to the front Insert Plate. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 74: Installing The Valve Bases And The Tag Strip
Using the designated hardware, install the 3 valve bases in their correct positions, as shown in the pictures above and below (the picture below shows an earlier version of the insert plate, but critical the orientation, which is , is correct). Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 74...
Page 75 Install the tag strip with 4 countersunk 6mm M3 screws from the top, then use 4 10mm hex standoffs and 4 M3 6mm pan screws from the underside. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 75...
Page 76: Installing The Jumper Wires
Before we install the resistors and capacitors and wire the valve bases, let's add some jumpers to the tag strip. This is quite straightforward: just take your time and be sure to use the correct tab. (The color of wire you use doesn't matter.) Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 77 Connect the Red wire coming from C on the 12-pin ceramic post in the Power Supply to M. Connect the Black wire coming from the top GND-D on the 12-pin ceramic post to I-GND. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 78: Installing The Resistors
Description 1K8 Ohmite Power Resistors 1K 1/2W AN Tantalum Resistors 220K 1/2W AN Tantalum Resistor 100K 1/2W AN Tantalum Resistor 220R 1/2W AN Tantalum Resistor 33K 1/2W AN Tantalum Resistor Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 78...
Page 79 Don't cut the lead you want to wrap too short! Take your be sure to solder them to the correct tab positions. time and Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 79...
Page 80 Referencing the picture above and the graphic on the next page, install the remaining resistors. Again, take your time and do a neat job. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 80...
Page 82: Installing The Capacitors
POSITIVE leads of the electrolytic capacitors. The film capacitor is non-polarized and can go either way; for aesthetics, we've installed them so as to be able to read the labelling. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 84: Additional Front Panel Insert Wiring
Finally, before we mount the Front Insert Plate, there are a couple of additional connections we need to make between the tag strip and the 6SH7 and 300B valve bases. Referencing the following graphics and the picture on the next page: Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 85 Connect an Orange wire from S to pin 6 of the 6SH7. Connect the 2 Grey wires bringing 6.3V AC from the Mains Secondary to pins 2 and 7 of the 6SH7. The orientation doesn't matter. That's it! Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 85...
Page 86: Section 7 - The Io Connections
Let's begin by installing the input RCA jack. Here's a picture of the RCA installed and wired: Insert into the chassis from the outside:  The white insulating washer with the raised ring facing inwards into the hole  The RCA jack Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 86...
Page 87: Wiring The Rca Input Jack
; it'll make soldering much easier in that position. Make sure everything is snug and well tightened. Wiring the RCA Input Jack Now we'll add the input resistors and wire things up: Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 87...
Page 88 Connect the free end of the 100K resistor to the ground of the RCA jack along with one end of the Black wire. Connect the other end of the Black wire to Tag I-GND. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 89: Mounting The Front Insert Plate
At this point, before we install and wire the Speaker Posts, we'll want to mount and secure the Front Insert Plate to the chassis. Mount the Front Insert Plate using the supplied hardware. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 90: Installing The Speaker Posts
Installing the Speaker Posts Referencing the following picture: Install the Red and Black speaker posts on the side of the chassis, as shown above. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 90...
Page 91: Wiring The Speaker Posts
Connect the Blue wire to the Red speaker post. Connect the Green wire to the Black speaker post. Cut the end of the Purple wire cleanly and cover it with a small plastic wire connector. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 92: Section 8 - Wiring Check Lists
Red wire to Pin 2 of top 300B (HT) Red wire from Output transformer Primary Pin 3 Black wire thru 1K resistor to Tag Strip C Pin 4 Red wire to Left DC-1 on Filament Supply board Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 92...
Page 93 One Black wire from One end of 30uf Mundorf Yellow wire from Mains Secondary Choke capacitor Not connected Not connected Not connected One end of 30uf Mundorf capacitor Green wire to top GND-D Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 93...
Page 94 Negative lead of 220uf 100V capacitor Black wire to bottom 300B Black wire to bottom of bottom 1K8 Positive lead of 220uf Tag A Pin 1 resistor pair 100V capacitor Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 94...
Page 95: Section 9 - Testing
 Test with a 'cheap' speaker for sonics and hum. If all is well, play in a proper system, enjoy! Before testing, it's a good idea to blow some air into the unit and make sure that there are no small pieces of wire or solder floating around. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 96: Installing The Fuse
That should help check some key connections and/or possible shorts. The picture is from a different build, but it's the same procedure. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 98 'Not connected" to make sure that, indeed, that are not connected. These are: 5U4-G Pin 1 Not connected Pin 3 Not connected Pin 5 Not connected Pin 7 Not connected 6SH7 Tube Pin 1 Not connected Pin 5 Not connected Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 98...
Page 99 Yellow wire from Mains One Black wire from One end of 30uf Secondary Choke Mundorf capacitor Not connected Not connected Not connected One end of 30uf Mundorf capacitor Green wire to top GND-D Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 99...
Page 100: First Power-Up
Just a reminder to 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. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 101 For the power-on test you will want to place the 8-ohm dummy load provided onto the speaker posts: Now let's position the amplifier on our work area with the inside up; notice how I've used a book under the transformers. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 102: Voltage Tests
You may find when you go to make a reading that the multimeter reads 0; you may want to press just a little harder with the probe (sometimes probes do not make great contact with the actual surface). Referencing the picture below and the table and graphic on the next page: Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 103 Filament (Pin 1) of bottom 300B and Tag 70V ± 5% Strip A Incidentally, the difference between the 70V and 75V DC measurements is the 5V 300B filament voltage, offset by 70V. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 103...
Page 104 We'll be happy to provide you with advanced troubleshooting advice. Note: we may ask that you send us high quality digital pictures of the internals of the amplifier. Let's also measure three important Power Supply voltages: Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 105 12-pin Ceramic Post A 450V Chassis Ground 12-pin Ceramic Post C 350V 7-pin Ceramic Post B 436V Well done if all these voltages are good! Let’s move on to the sound check. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 105...
Page 106: Sound Check
5V without the tube in place. If things are still not working, contact ANK Audio Kits at audionotekits@rogers.com. We'll figure things out. Please have a few telling digital pictures ready to share with us.
Page 107: Section 10 - Finishing Touches
Glue or attach (with some Blu Tack) the LED holder to the front panel so that the LED protrudes through the designated hole, as shown below: 10.3 Installing the Chassis Top Install the chassis top using the provided hardware. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 107...
Page 108: Section 11 - Final Thoughts
If you've made it to this point then CONGRATULATIONS! — you are ready to insert your Legend Monoblock 300B-2A3 Parallel SET Amplifiers into your real system, sit back, and enjoy the music. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com...
Page 109: Break-In
Like life, sometimes it’s “love at first sight”… and sometimes it just takes time. 11.3 Cables In our experience, a high quality power cable and good interconnects and speaker cables make a noticeable improvement to the sound. Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 109...
Page 110: Tube Rolling
11.4 Tube Rolling We feel that the sound of the ANK Audio Kits Mentor SET Power Amplifier is truly sublime and that is destined to become a popular kit. It provides a highly detailed and transparent presentation with gorgeous sonics. Rolling some quality new production tubes and/or some nice NOS tubes will allow you to tailor the sound to your particular preferences.
Page 111: Thanks
11.5 Thanks Thank you for investing in the ANK Audio Kits Legend Monoblock 300B-2A3 Parallel SET Amplifier and congratulations on working your way through the build. The manual is new and we would welcome your feedback. Please email us at audionotekits@rogers.com and let us know how everything went: were there any errors in the manual or instructions, parts lists, etc.? Your ideas...
Page 113: Resistor Color Code Reference
You can also find an 'Interactive Resistor Color Code Calculator' on our website (available from the Links page). Copyright © 2019 ANK Audio Kits www.AudioNoteKits.com audionotekits@rogers.com Page 113...

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