I'm working on wiring the PT and am not sure the best way to proceed. Everything pretty much makes sense up until I try to wire the heaters. The wires from the transformer are a huge 14 awg brown wire, which is fine except how on earth can I connect them to the tube socket? I have two holes per pin that would each only accommodate about half of the 14 gauge wire. Is this how you connect? Split the strands in 2 parts and run them through the holes? Put half through one hole and wrap the rest around the pin? What is the best way to do this
You can use a small terminal strip to transition to higher guage wire. Its not in the layout? I'm doing an express too but only have the preamp board done. I think I have pics from another build or two
Picker wrote:I'm working on wiring the PT and am not sure the best way to proceed. Everything pretty much makes sense up until I try to wire the heaters. The wires from the transformer are a huge 14 awg brown wire, which is fine except how on earth can I connect them to the tube socket? I have two holes per pin that would each only accommodate about half of the 14 gauge wire. Is this how you connect? Split the strands in 2 parts and run them through the holes? Put half through one hole and wrap the rest around the pin? What is the best way to do this
Thanks all
I went through that a few years ago asked the same question. You can use a turret strip, use can trim the fat wire down until it fits the tube socket, or you can pigtail a solid wire to the stranded large wire then solder allowing to easily use the solid piece in the tube socket.
I have some 18 gauge tranny clippings. Would it be okay to solder a short piece of that to the 14 gauge, shirnkwrap it, and then connect the 18 gauge end to the tube socket?
Picker wrote:I have some 18 gauge tranny clippings. Would it be okay to solder a short piece of that to the 14 gauge, shirnkwrap it, and then connect the 18 gauge end to the tube socket?
Is that what you meant by pigtailing?
If you do it this way, remember, solder is *not* glue. Make sure you have a rock solid mechanical connection before you solder, and make sure the solder really soaks into the strands.
I didn't have a turret strip on hand and considered using a wire nut to connect the 14 gauge to a smaller wire, but did not like this idea much. I ended up using the option I described earlier where I put about half of the strands through the hole and wrapped the rest around the pin. It looks pretty solid, so I thinik this will work for me and seems to be a good option.
Progress is slow and haphazard since I'm not strictly following the order of things listed in the Build guide. For example, the pots were one of the first things I worked on since I knew I would have trouble with this and wanted to get it out of the way (also the impedence selector). However, I have not yet completed the wiring for the Presence Pot or the birght switch. Then I started working on the boards. With them assembled I have started working on wiring the transformers and now the heaters. Next I will work on finishing the Presence Pot and Bright switch and move on to wiring the preamp tubes and connecting everyting to the boards. Then I'll assemble the Cap stack and wire that in.
It seems kind of random to work on different sections and moving on to the next thing without completing the one I started, but I think it will work out. As I said, progress is slow, but progress is being made. I hope to put a couple of hours in this weekend that should bring me closer to the finish line.
Picker if your in the U.S. and have a Radio Shack store near they stock turret strips.
Guys, make a solid connection from large wire to smaller wire then solder, shrink wrap and insert wire through tube socket ortherwise the turret strip or similar device is needed.
...So you would NOT recommend doing it the way I described? Using 1/2 through the hole and wrapping the rest? It looks like it is not touching anything else and the connection looks solid.
I looked at the Teminal strips in Radio Shack and wasn't very impressed with what they had. I could use them, but I think the solution I was using looks like it would be better.
Is there a reason I should avoid doing what I did?
Finished up the Pots. I had needed to add the Bright switch and Presence pot connections.
On the bright switch, I added the 100pf and 500pf caps when the pot assembly was off the chassis and inadvertently made the connection longer than I intended. When I add a drop if silicone, I can glue the caps together, but I'm too far away to glue them both to the bright switch as suggested in the Build guide to "prevent parasitic oscillation". Instead, I am close enough to place some silicone under the caps and glue them to the floor of the chassis. Would this be fine and serve the same purpose? I hope so, it was difficult getting them attached, so I would rather not take it apart and redo it.
Regarding going from 14 to 18 using turret strips, why not just use all 18awg and do away with the 14? If you bring it down in size the circuit will only be as strong as the weakest link/smallest wire anyways.
The 14 gauge wire is what is coming out of the Power Transformer. It is not something I chose. It connected fine using the method I described (half through and wrap the rest). I didn't need to convert to the 18. I'll be using the 18 gauge wire to wire the heaters from here on though the other tubes.
This may be a foolish question, but I was a little confused by the heater wiring. From the Build guide, it looks like I just connect Pin 2 to Pin 2 and Pin 7 to Pin 7. However, in the pictures I look at if I trace the wires, it looks like Francesca has the wires going from 2 to seven. Maybe it just looks that why though, or maybe that is what the guide meant by a possible wiring problem in Francesca that resulted in it being out of phase.
I'm thinking I am supposed to wire 2 to 2 and 7 to 7.
Oh I didnt realise you were talkin about the wires off the OT.
The heaters land on pins 2 and 7 of the power tubes and then on the pre-amp tubes 4-5 and 9. Whatever color you use on pin 2 goes to pin 2 of next tube then over to the pre's whatever color you are using goes to 9 on the first pre goes to 9 on the rest of them, and then the wire that goes to pin 4-5 you can do a couple different ways, I over strip both leads, run them through pin4 then through pin 5 wrap then solder. Others may do it differently but to each his own.
Also, wiring the heaters on your power tubes correctly helps cancel hum, but there are tons of vintage amps out there where they crossed them, especially old Fenders. I usually lay one of my heater wires flat on my bench and run a stripe across it with a sharpie so I can easily tell them apart. Some people use different color wires for the same reason.
