Manual Version March 2007

Transcription

1 Manual Version March 2007 Page 1

2 Table of Contents Section1: 6922 Line Board Build Line Board Version Notes Line Board Build - HARD-WIRED VERSION... 5 Final Connections and Checks for 6922 Hard-Wired Board... 9 Level B Hard-Wired Board Example Pictures Section 2: Line Board Filament and HT Appendix Resistor Color Code Reference Analog Board Schematic (Level A) Analog Board Schematic (Level B) Page 2

3 Section1: 6922 Line Board Build We have included schematics for both the Level A and Level B versions of the 6922 board in case you want to upgrade at some point. The only difference is that the Level B version has an additional 330R and 820pf capacitor in parallel at the input and this circuitry is required by the IV transformers so you will need to incorporate this circuitry into your build of the 6922 board. So, once again If you are building a Level B DAC2.1 there is some additional circuitry surrounding the I/V transformers that we will want to incorporate onto this board The schematic insert shows the Level B version of the 6922 board with the addition of the 820pf and 330R resistors on the input. See the schematics in the back of the manual. Page 3

4 If you are building a Level A DAC2.1 then you will be building the 6922 board with the Level A schematic shown below. Page 4

5 6922 Line Board Version Notes There are two versions of the 6922 board available. The Standard Copper Track PCB board is considered to be the simplest board to build whereas the Hard-Wired version is usually the choice of the more experienced builder. This manual is dedicated to the Hard-Wired (trackless PCB) version. Also, note that both methods will vary slightly between Level A and B. Level B will require additional interface components - these are discussed in the instructions Line Board Build - HARD-WIRED VERSION Refer to the schematics (LEVEL A or LEVEL B) provided for this section so that you will build the 6922 board compatible with direct connection to the digital board (Level A) or through the IV transformers (Level B). We are now going to build the 6922 Board. We are not going to provide you with exact instructions for this section but I think it is fairly straightforward to make the connections required by using the (Level A or Level B) schematic and I will help you along! This gives you some flexibility to make your own best routing decisions. We will get you started however! 1. Install the 4 hex spacers on the board this makes it a little easier to work with. 2. Insert the 9 pin valve bases into position and use the 6mm round spacer to support the valve base Insert the M3 16mm PAN head screw into position. 3. On the underside of the board you will want to add in the ground tags between the M3 nuts as shown below. Page 5

6 4. Next step is to install the ground strip using the silver wire and insulation. Notice how the shrink-wrap covers two main sections of the ground plain. 5. We are now set to start wiring. If you check the schematic you will notice that pin 1 on both valves is connected to 230V. This is what we call the HT (or High Tension) It s basically the high DC voltage that the power supply puts out. Please note that this board is very versatile and used in several kits so do not use the white lines on the board as reference for connections. 6. The HT inputs to the board are W38 and W39 on the board so we are going to start by taking some silver wire and hooking straight from W38 to pin1 and W39 to pin 1 on their respective sides of the board. You will also notice on the schematic that pins 2 & 6 on each tube are connected together. Page 6

7 When I first built this board I found that it was getting complicated to put all the components on the topside of the board so I found it a lot easier to out components on both sides of the board as you can see here. I will leave it to you if you would like to put all your components on top or a mixture of both as I have done! Page 7

8 Here is a list of the connections that you will need to make and you can verify on the schematic. These can be performed on each valve base. A tip that I will suggest when using the silver wire is not cut the piece to length but rather hold on to the roll or a long piece and solder one end to a connection point the wire can get hot when soldering so its get difficult to hold it Once the connection has been made on one end then cut the silver wire to the length and try to make it mechanically stick to the second point then it s a matter of soldering. A. Connect pin 9 to pin8 B. Connect pin 6 to pin 2 (already done) C. Connect 470 ohm resistor (470R) between pin 2 and 3 Here is the topside of the board with roughly half the components on this side. The copper caps provide will have plastic insulation on them and you will want to keep this on the caps when they are installed, as the copper shell is conductive. For the LEFT Channel make these additional connections: 1. Connect a 1K resistor between pin 7 and W41 Bend the resistor through W41 so that you will be able to connect to it later. 2. Connect a 470K resistor between W41 & W Connect a 470R (that s 470 ohm) resistor from pin 8 to GND (wire running through the center of the board). 4. Place a 470uf 16V capacitor in parallel with this + side to pin 8 and side to ground. 5. The large 0.47uf 600V copper cap will be connected between pin 3 and W Connect a 1M (1.2M) resistor between W35 & W36. For the RIGHT Channel make these additional connections: Page 8

9 1. Connect a 1K resistor between pin 7 and W43 Bend the resistor through W43 so that you will be able to connect to it later. 2. Connect a 470K resistor between W43 & W Connect a 470R (that s 470 ohm) resistor from pin 8 to GND (wire running through the center of the board). 4. Place a 470uf 16V capacitor in parallel with the 470R: + side to pin 8 and side to ground. 5. The large 0.47uf 600V copper cap will be connected between pin 3 and W Connect a 1M (1.2M) resistor between W37 & W36. Final Connections and Checks for 6922 Hard-Wired Board Make sure that W38 and W39 are connected together on the top of the board with a wire see top of board picture on the previous page. It would be a good idea to use an ohmmeter to check your wiring with the schematic Here are some checks you can test for: 1. W42 (GND) and W36 (GND) are connected 2. W39 and W38 are connected 3. 1K between W41 and pin K between W43 and pin R between pin 8 and GND R between 3 and pin2 Make sure that pins 4 and 5 are empty on each valve base this is where the filament wires will connect. The filament connections will be discussed in the next section. Page 9

10 Level B Hard-Wired Board Example Pictures Level B board pictured from the top Level B board pictured from the underside Page 10

11 Section 2: Line Board Filament and HT In this section we will connect up the High Voltage (HT) from the M2 Power supply Board to the Line Board along with the Filament Voltages. Step 1: Solder some wire between the HT on the M2 power supply board and the 6922 analog output board You should already have a wire connecting W38 to W39. You will want to solder a wire from the B+ on the M2 Power Supply to W39. Also connect a ground wire from the GND on the M2 power supply nearest the LED section and connect to W36 on the 6922 analog Board Step 2: Connect a red/black twisted filament wire from the M2 power Supply Filament (6V2) and connect to pins 4 & 5 of the first tube. Repeat this procedure for the second tube Both tubes will have their own dedicated filament supply. With a completed 6922 board you will probably want to run a quick test. Power on the Main rocker switch and check that the 6922 tubes are lighting up. You can also do a voltage check on the HT line W38 on the 6922 board to see if all is well. This voltage can be adjusted by turning VR1 on the M2 power supply board. Get the voltage as close to 230v as you can. Well done! The hard part is definitely over! Page 11

12 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 12

13 Resistor Color Code Reference You can also find an 'Interactive Resistor Color Code Calculator' on our website (available from the Links page). Page 13

14 Analog Board Schematic (Level A) Page 14

15 Analog Board Schematic (Level B) Page 15