Specifications

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“Baby Will” Valve Junior Conversion Version 4
Build Manual 22 September 2009
5 of 36
Table of Contents
1. Introduction ............................................................................................................................. 2
2. Electrical Shock Warning........................................................................................................ 4
3. Disclaimer of Liability .............................................................................................................. 4
4. Project Overview..................................................................................................................... 6
4.1 Here’s what you’ll need: ................................................................................................. 6
4.1.1 Parts: ..................................................................................................................... 6
4.1.2 Tools: ..................................................................................................................... 6
4.1.3 Supplies: ................................................................................................................ 6
5. Let’s get started…................................................................................................................... 7
5.1 Remove the EVJ chassis ............................................................................................... 7
5.2 Remove the EVJ’s Stock Components .......................................................................... 8
5.2.1 Remove the Tubes and Tube Retainers ............................................................... 8
5.2.2 Remove the Output Transformer........................................................................... 8
5.2.3 Clean Up the Power Transformer........................................................................ 10
5.2.4 Remove the Volume Potentiometer .................................................................... 11
5.2.5 Remove the Stock EVJ Circuit Board.................................................................. 11
6. Prepare the Chassis ............................................................................................................. 13
6.1 Layout and Drill ............................................................................................................ 13
6.1.1 Layout the Drill Plans........................................................................................... 13
6.1.2 Drilling the Chassis.............................................................................................. 14
7. The Baby Will........................................................................................................................ 16
7.1 Assemble the Baby Will Circuit Board.......................................................................... 16
7.1.1 Tube Sockets....................................................................................................... 16
7.1.2 PCB Standoffs ..................................................................................................... 17
7.1.3 The Power Grid ................................................................................................... 17
7.1.4 Signal Path and Cathode Resistors .................................................................... 19
7.1.5 Sag Resistor ........................................................................................................ 19
7.1.6 Signal Path and Cathode Capacitors .................................................................. 20
7.1.7 Hum Balance ....................................................................................................... 20
7.1.8 Filter Capacitors and Ground Wire...................................................................... 21
7.1.9 Jumper Wires ...................................................................................................... 21
7.1.10 Input Jack Hookup............................................................................................... 22
7.1.11 Volume and Tone Controls.................................................................................. 25
8. Putting it All Together............................................................................................................ 26
8.1 Install the New Components ........................................................................................ 26
8.1.1 The New Output Transformer.............................................................................. 26
8.1.2 The Baby Will PCB and Tube Hardware ............................................................. 28
8.1.3 Hookup the Leads to the Baby Will ..................................................................... 29
9. Turn on the Power ................................................................................................................ 31
9.1 Check Your Work ......................................................................................................... 31
9.1.1 Take a Break ....................................................................................................... 31
9.1.2 Visual Inspection ................................................................................................. 31
9.2 Power Up without Tubes .............................................................................................. 32
9.2.1 The First Power Up.............................................................................................. 32
9.3 Power Up with Tubes ................................................................................................... 33
9.3 Power Up with Tubes ................................................................................................... 34
9.3.1 The Real Test ...................................................................................................... 34
11. Finish Things Up............................................................................................................... 35
11. Finish Things Up............................................................................................................... 36
11.1 Re-Assemble the Amp ................................................................................................. 36