7 - Building the main turret board
barry (Administrator) 12-30-2013 at 09:32 PM.
Post: #1
The first step in building the main turret board is to fit the board in the chassis. Use five M3 shakeproof washers and nuts to do this, but for the two mounting points at the bottom-left and bottom-right add the M3 solder lugs. These will be the grounding points for the board's components.

[Image: n5xtb01.jpg]

Now join the turrets shown with the three wire links:

1) a bare bus wire that runs from the ground lug at the bottom left edge of the board

2) a bare bus wire that runs from the ground lug at the bottom right edge of the board

3) an insulated red wire as shown here.

Solder these wires around the shaft of the turrets, leaving the turret holes empty and ready for components.

[Image: n5xtb02.jpg]

Once again, for insulated wires, it’s best to tin the end with solder and then bend it to create a ‘hook’ that you can place around each turret shaft - shown here in step-by-step form). Use needle-nose pliers to crimp the hook around the shaft of the turret and then solder it into place.

[Image: n5xps04.jpg]
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barry (Administrator) 12-30-2013 at 09:39 PM.
Post: #2
Adding the board components
Take your time as you populate the turret board with components. Double check that you have the right component before you trim its leads ("measure twice and cut once").

Some components are a tight fit and it's worth doing a 'dry run' before you start soldering. In particular C14 and C15 are quite bulky and make it a little tricky to solder adjacent components. One way around this is to solder C10+R16 and C11+R17 one above the other, as shown in this diagram.

[Image: n5xtb04.jpg]

Note that all of the blue/black capacitors have a polarity and in this turret board the negative terminal of all of them points towards ground. (Note that for reasons that are lost in the mists of time, it's conventional to indicate postive terminals on schematics, but negative terminals on the capacitors themselves. So I've shown both on this diagram to make things clear!)

[Image: n5xtb03l.jpg]

CLICK HERE for the high-resolution version of the above diagram.

TIP: If you find it difficult to get several component leads into one turret top, you can also solder the leads to the side of the turret instead. As long as you have a good solder joint, it's electrically (and tonally) identical.
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barry (Administrator) 12-30-2013 at 09:47 PM.
Post: #3
Final turret board components
With the on-board components added, you have a handful of components left over: R1, R2, R8, R15 and R18. Most of these connect the turret board to the valve sockets.

Now trim and solder R2 and R8 in place, connecting the board to the V1 valve socket (pins 2 and 7, respectively). See below.

[Image: n5xtb05.jpg]

For resistors R15 and R18, trim them to length and solder them at the turret board end only. (You will add an extra wire and solder them to the V2 valve socket later.)

[Image: n5xtb06.jpg]
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barry (Administrator) 01-20-2014 at 04:55 AM.
Post: #4
Direct links to reference diagrams
This guide is written in several sections, ranging from a basic description of the N5X to very detailed instructions on how to build each and every part of the amplifier. I recommend following it step-by-step and paying attention to the tips and suggestions.

However, if you're an experienced amp builder, you may just want to dive into the build and do it your own way. To make that easier - and for easy reference for all builders - this, the last entry on each page, lists the important reference diagrams:

* Schematic
* Power supply board
* Main board
* Finished layout
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barry (Administrator) 01-20-2014 at 06:09 AM.
Post: #5
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