SSS heater lead dress

[Lothy]

Greetings!

I'm just thinking, if it is a good idea, if I use Valve Wizards suggestion (pic 3)

heater10.jpg

on the reverb driver tube:

Screenshot 2024-02-28 165741.png

Maybe it's ok, but I wanna know for sure. I don't want to rip everything apart afterwards...

Thanks.

Gerhard

[bepone]

the best way not mentioned , not even in "valve wizards" book, bring 12.6V to terminals 4-5 and bypass socket elegantly

[Lothy]

the best way not mentioned , not even in "valve wizards" book, bring 12.6V to terminals 4-5 and bypass socket elegantly

From where?

[ViperDoc]

You want the signal wires away from the heaters, so if you're going to parallel the heaters over the 4/5/9 orientation, you can either fly the socket connections over, or loop them on chassis. I would think that crossing everything over itself over the heaters would lend itself to noise in the reverb circuit. The AA1164 reverb socket needs a certain loop I don't recall off the top of my head. Point being, those circuits are touchy.

[bepone]

the best way not mentioned , not even in "valve wizards" book, bring 12.6V to terminals 4-5 and bypass socket elegantly

From where?

ha? you didnt know that you can use 12.6V for the heaters? you can use any small 12V trafo 1-1.5A, screwed inside the chassis

[Richard1001]

Seems to me that Valve Wizard is fixing something that isn't a problem. I used filament wiring A in my SSS and B in my ODS ( a little tighter wound though). There is no hum at all, regardless of volume and gain settings.

If there is filament hum present in a properly wired amp, it is most likely due to the internal filament wiring in the preamp tube inducing hum on to the cathode. This is the reason old amps had those huge (250uf) cathode bypass capacitors. The big capacitor bypasses not only the signal, but also the induced hum. Spiral filaments prevent induced hum on to the cathode (7025). In al lot of modern tubes spiral heaters are common. Tubes with spiral heaters should not be used as cathodefollower though, due to the smaller spacing from the heater wire to the cathode.

Using the second triode of a 12ax7 (678) first will also reduce the hum.

[timrobertson100]

If it helps, I have pics of my SSS wiring on pg2 of this thread and it has no hum. There is some discussion about it on there, but I opted for option A partly because (almost) all the other connections come down vertically.

You can see on Erwin’s build he did the option you are considering on his thread.

[Lothy]

ha? you didnt know that you can use 12.6V for the heaters? you can use any small 12V trafo 1-1.5A, screwed inside the chassis

I should have known, there is no free lunch...

[Lothy]

Thank you all, for your quick reply. I think I go with option 3.
Cheers
Gerhard

[sluckey]

I'm just thinking, if it is a good idea, if I use Valve Wizards suggestion (pic 3)

Merlin's pic #3 would look much better if the socket were rotated 180° so the filament wires could enter the socket in the wide space between pins 1 and 9.

And the jumper between pins 1 and 6 usually makes a loop around the perimeter of the socket rather than crisscrossing. See this pic...

But your layout looks like the socket will be mounted on the board? If that's the case, none of this really matters.

[rootz]

Have a look at the SSS#001 gut shot. Clearly Dumble used the method from the first picture. I'd call that the Marshall method. Pretty silent in low gain amps. Must add that the visible grid wires in 001 all pass the heater wires at more or less a 90 degrees angle.

I strongly prefer the third method, but that is simply not possible in an SSS.

FWIW, I do all 005 builds with method one on the preamp and reverb mixer tube. Those amps are silent.

[chaccmgr]

in my designs I used both approaches and never had a hum issue. Lately I stick to Merlin's approach using the gap between Pin 1 and 9
make sure that other wires have a good clearance to the heater wiresand if necessary at all, let them cross in 90° angle or loop them over the socket. I prefer looping the signal wires rather the heater wires. i want to have them close to the chassis to reduce the electromagnetic field

[Lothy]

That's as good as I can make it.

IMG_20240229_211121.jpg

I think, it should work.

Cheers
Gerhard