9 - Output transformer connections
barry (Administrator) 12-30-2013 at 10:57 PM.
Post: #1
Your final connections will complete the signal path of the amplifier. At the moment, the signal path to the power valves is all in place, so all that remains is to connect the power valves to the output transformer and the output transformer to the speaker sockets.

For the speaker sockets, first take a piece of bare bus wire and run it from the grounding lug on the bottom of the chassis, then up to and through lug 3 of the 4Ω, and then through all of the lugs 3 and 4 for the other sockets.

Solder all of these lugs except lug 4 of the 8Ω socket. For this lug, we add the orange wire from the output transformer. Trim this wire to length and solder it in place, making sure to also solder the ground bus wire you've added, too.

Now trim and connect the grey, green and yellow wires, one each to lug 1 of each of the speaker sockets. Solder these three wires.

[Image: n5xfin01.jpg]
- - Quote -
barry (Administrator) 12-30-2013 at 11:00 PM.
Post: #2
Final connections
There are only a few remaining wires to connect. First, take the brown and red wires from the output transformer's primary winding and twist them together while running them over to the V3 valve socket. Take the brown wire to pin 3 of the socket, and trim and connect it but don't solder it yet.

Add a short brown wire to connect this pin to pin 7 of V2 and solder both pins. This wires the two valve sockets in parallel, allowing you two swap between an EL84 and a bigger octal valve without making any changes inside the amplifier.

[Image: n5xfin02.jpg]
- - Quote -
barry (Administrator) 01-19-2014 at 01:58 AM.
Post: #3
Connecting the turret boards
Take the red wire from the output transformer over to the turret at the top end of C15 - it will connect here, so trim it to length. But before you solder it, this turret also needs a connection to the output of our VVR circuit on the other turret board. So take some pink wire and run it from this turret to the D1+R22 turret on the power supply board.

[Image: n5xfin03.jpg]

And finally, there's the preamp's power supply wire to add, also between the two turret boards. Take some red wire from the as-yet-unconnected turret at the end of R19 on the main turret board and run it over to the power supply board, to the turret where C13 and R20 meet. Solder this wire and you're all done building.

[Image: n5xfin04.jpg]
- - Quote -
barry (Administrator) 01-20-2014 at 04:52 AM.
Post: #4
Your finished amplifier
Now that it's completed, the inside of your N5X chassis should look something like this:

[Image: n5xtbw14l.jpg]

CLICK HERE for the high-resolution version of the above diagram. The only important difference is the wiring changes for non-240V mains supplies, and this affects only the wires at the bottom right of the diagram. (And as you've already tested the power supply board, your wiring here should be OK anyway.)
- - Quote -
barry (Administrator) 01-20-2014 at 05:57 AM.
Post: #5
Direct links to reference diagrams
- - Quote -
Post Reply