Twisted pairs- for heaters

[Koolaide]

Hi all.
Been thinking about twisted heater filaments in my Express build. I know it is not traditional, but has been done.
I was wondering the advantages and disadvantages on this. Also I have never seen any with the heaters flying over the socket ala Fender, although I understand this is considered a good way to do heaters. Please post your experiences, or thoughts.

Thanks,
Jim

[pompeiisneaks]

I thought on the layouts I've seen and in a few pics of TW amps, they are twisted, just very loosely, not worrying too much about exact winding, being super tight etc.

At any rate, twisting them isn't going to impact the tone of the amp in any way, it will very minimally reduce any 60Hz hum that may inject into the signal path, but due to my own experimentation and that of many others, super tight winding of heaters isn't as big of a deal as just making sure they come into and away from the tubes at right angles and as far away from the signal path as possible. Fender's over the top accomplishes this very well, I learned my style from reading the valve wizard's book on it where he twists them tightly and then runs them away from the tube and runs them back in just at the right angle to go into the heaters w/o impacting any other wires the best that you can. he even has some great pictures of good vs bad in the book and on his site here:

http://valvewizard.co.uk/heater.html

view the section at the bottom about 'Layout / Lead Dress'

~Phil

[Turbojunkie]

I was wondering about the specific reason for the few/loose twists in a Trainwreck , as every reference book I've seen points out that tightly twisted heater wires are an important aspect of noise reduction, along with socket connections and distance, etc.

[ChopSauce]

Dogma live well in books. They may not survive in the garage ...

In other words: the writers of those books might not be professional builders. You should be asking the writers, maybe ...

[xtian]

Twisting is a simple way to keep the two heater wires close together. That's what cancels the hum, not the fact that they're twisting. In practice, I've found it impossible to cause hum in a triode gain stage by intentionally running a single heater wire near the input grid. Though my experiments were not with high gain amps.

[Turbojunkie]

Agreed, real world experience is most important...if Ken found that a couple of loose twists was all that was required, it makes sense for sure...just didn't understand why it's such an anomaly.

[Turbojunkie]

Ah...so it's overkill? In reality the truly important thing is that heater wires as close as possible, and tight twists are just a way to accomplish that in a clean and tidy way...Good to know, thanks guys.

[Koolaide]

Thanks all for the replies and input. Clears things up for me.

[ChopSauce]

Straight from the SLO

002-5.jpg

[norburybrook]

Mike from Modulus amplification here in the UK and a forum member uses CA glue to jeep his heater wires together but NOT twisted. He makes great amps.


I'm a traditionalist.


Fender: Twisted, elevated

Marshal: Twisted along the Chassis edges

Dumble: see fender

Trainwreck: loosely twisted.


M