Heater Wiring

[Gibsonman63]

I should be running my heater wiring in the next few days on my express build and I notice that the approach is much different than any other amp I have seen. Generally, on the hand built amps, you see these tightly twisted wires that are oriented over the tube sockets. I am going to go with Mr. Fischer's method because I don't feel smart enough (yet) to venture out on my on.

Can someone enlighten me to the method behind the madness here?

Have any of you guys tried this with a more traditional arrangement?

I know that heater wiring can be very critical because moving them around with chopsticks in my vintage Fenders has worked wonders for them and they are fairly low gain amplifiers.

[M Fowler]

I have built the Express with both the Ken F. Lazy loop and tightly twisted method.

The problem with the Express is in the lead dress for the rest of the amp in my opinion. Especially V1 and V2 wire to the boards.

[rooster]

The loose method is rather Marshall-y, and so Ken didn't create this per se. That said, I have used the tradional Fender style filament wiring, twisted and run over the tubes, on every TW clone I have built. Either works fine it seems, and, like Mark says, it will not be the filament wiring that causes you a problem.

So do it in a way that you are more familiar with.

BTW, when you say that you have moved some Fender filament wires around and improved things, well, that seems odd. Fender amps are such low gain the filament is rarely an issue. You might revisit those amps and find it was not the filament wiring at all. I mean, anything is possible, but I just don't see this problem with the Fender amps. Now, if you are talking about a tweed circuit where one side of the filament supply is grounded to chassis, well, yes, that supply could be improved by referencing the filament supply with two 100 ohm resistors to ground. ?? Is this what you refer to?

[Gibsonman63]

I have decided to go the lazy loop approach. It is a little easier said than done getting those wires into the preamp socket lugs, but I should be done with that tonight.

For the Fenders, specifically, the tremelo circuit seems sensative. Last year, I rebuilt a 1965 Twin Reverb that had gotten wet and then stored in a garage for 20 years (But I got a really, really good deal on it ). Everything fired up fine when I finished except for a ticking tremelo circuit. I was probing around with a chopstick and found that moving the heater wiring fixed it. Of course the other issue is that Fender did not pay attention to polarity of the heater wires on the power tube sockets. I have had to fix that on every Fender I own that has more than one power tube. I have been twisting them tighter and standing them up away from everything else as well. After a while, you just do some things because it seems to be good practice to do it.

[Dano]

Gibsonman63

It is a little easier said than done getting those wires into the preamp socket lugs, but I should be done with that tonight.

I'd be really curious to know the proper techniques for fitting 2x18awg wires in 9 pin socket lugs.

I was tearing wiring out right and left from failed attempts on my Rocket build. I finally started clipping the tinned leed ends to a sharp point and jamming both in as best I could.

There's got to be a better way though, right?

Dan

[Gibsonman63]

I have to admit, that I am cheating on mine. I tried various methods for about 25 minutes and wasn't able to make it fit. The closest I got was by twisting the ends really tight, tinning it and then cutting a little off of the end to get to the smallest point, but I still couldn't get it to go through the hole. After a lot of frustration, I ended up just putting one wire through and then looping the second wire around the first and soldering them together. I am always open to a better idea.

I am coming to find out that amp building is much more tedious than amp repair or amp restoration.

[Merlinb]

There's got to be a better way though, right?

Thinner wire perhaps?

[Gibsonman63]

Merlinb, you may be on to something... sort of a forest and trees issue, I guess.

I plenty of 22AWG solid core wire and it is easy enough to run the 18AWG stranded up to the phase inverter. I should be able to get a 22AWG wire in with the 18AWG on the PI socket. Any problems with running 22AWG solid fromthe PI to V1 and V2?

[billyz]

I use 20AWG for the filaments , no problems. I use 22 ga for the rest of the preamp. I am sure 22 AWG work fine for the Filaments as well. I did the math a long time back and it was adequate for the current in a Wreck.

18ga is too big for any preamp socket I have used. I did use it on a few but always cut the tail to 20ga. And used solid jumpers (cutoffs from cap and resistors).

[gary]

aesthetics aside, how about a solder tag to effectively enlarge the terminal ?

[ChrisM]

20AWG for preamps, 18AWG for output?

[PlinytheWelder]

What's key in the wire dress is to have the problem wires cross at right angles. That and wire separation is the way to minimize crosstalk and the other nasties that can plague these amps.

IIRC, I used Belton sockets and a weird machined Teflon one for V1.
I used all 18ga for the heaters and it fit the Beltons, but that V1 socket was a real PITA....

[Structo]

I believe 20 gauge wire is more than sufficient for the heater wires in those amps.
20 gauge chassis wire has a max capacity of 11 amps.

On one amp that I used 18 gauge on I did not twist the bare ends together but rather stacked the two wires one on top the other to fit in the socket pin eyelet.

[M Fowler]

I'll open my big mouth and state that I used 18 gauge filament wire without problems and use 20 gauge for the rest of the amp. I sometimes use 22 gauge but rarely.

You will run into situations like I did in the past when the output wiring is so large that one has to either trim some strands down or use a turret stip before the tube socket.

[Structo]

That raises another topic.
The gauge on the transformer itself.
I was a bit surprised when I first got back into tube amps at the gauge of wire on the secondaries.
Of course those are very short runs so that may be why but they sure seem small.

I never measured the gauge on them but they can't be bigger than 20ga maybe 18.