Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: joesatch on November 01, 2021, 08:14:00 am
-
everyone loves to show you the drill trick but when twisting cloth heater wires i don't think that is a good idea. How do you folks twist cloth heater wires?
-
I use a drill, cause it's faster and you can get them tighter and more evenly twisted. I twist up a long section, foot or 2, and cut pieces as needed.
You can do them by hand, just takes longer.
-
On twisting heater wires---isn't it just as good to run the wires beside each other and parallel as it is to twist them? never had the nerve to try this but seems I have seen info that says it.
-
i just do it by hand but learned the hard way not to use solid core wire.... getting everything twisted nicely and wrapped onto tube pins just to have one of em break is aggravating
-
ya i'm not chucking up my cloth wires on a drill. I'll do it by hand. drill is fine for pvc wire but not cloth
-
once I stole this concept from Sluckey and others, I never looked back.
filament induced noise is all about sensitive signals getting to close, not the twist.
the chassis itself acts as a shield when you tuck 'em in the corner
-
What's the problem with twisting cloth? I can easily get my knickers in a twist. OK, a too-tight chuck will ravel the cloth at the end. But you cut that off. Or strip it. Or loop through a hook-eye.
You twist because in side-by-side, one wire is always closer to the point being interfered-into. Twisted tighter than the distance to the point being interfered-into, the average distance is about equal for each wire. (Which means super-tight twist is often pointless, strains and wastes wire.)
Find some Ethernet cable (or online pictures). That stuff is highly optimized for its era. CAT3 is twisted mostly to keep it together, although also to reject hum from power cable in the same wall. CAT5 twist is highly specified so huge masses of cable do not crosstalk to each other. CAT6 goes further, basically because Belden built better machinery and challenged the market. 1 twist per inch is roughly a good number.
-
It is so easy by hand I never thinking the need of a drill,
Useful if you have few dozen of amp to built
-
@PRR:
1 twist per inch is roughly a good number.
Just so I'm clear, are you talking about CAT6 cable here, or guitar amps? I've seen recommendations to put in four twists per inch on guitar amps. But you seem to be suggesting that one twist/inch is okay?
Thanks
-
ya i'm not chucking up my cloth wires on a drill. I'll do it by hand. drill is fine for pvc wire but not cloth
Like PRR wrote, you just cut the ends off that were in the drill chuck.
That's the whole point of using push back cloth, no stripping, just cut the ends.
What's the problem with twisting cloth? OK, a too-tight chuck will ravel the cloth at the end. But you cut that off. Or strip it.
-
It is so easy by hand I never thinking the need of a drill,
Useful if you have few dozen of amp to built.
It's not so easy by hand to get the twists even and tight, very slow. And now your working inside the chassis to twist those wires. Later Fender and Marshall chassis' aren't as bad, but Tweed chassis are more difficult because of the restricted space.
The more I can do outside of the chassis the better.
-
I’ve stopped twisting.
I run straight paralleled runs (sometimes heat shrinked together) tucked in the corner of the chassis.
I think the best argument for twisting is that it is convenient to keep the two wires together and parallel. I see heaters that are super tightly twisted and can’t understand why it would be better then loosely twisted.
-
I my not always twist.. but when I do .. I always twist to this tune ..
-
I bought teflon wire from an ebay vender he offered to twist the green (heater) so I said might as well! :icon_biggrin:
-
I my not always twist.. but when I do ..
was camping in East Kentucky with a dozen teens the campground had a Saturday night Hoe-down. they started playing the twist n I grabbed a couple of the shy teens n said "we're up" I won 2nd place doing Travolta's version of the twist. My high water mark for dance :icon_biggrin:
-
I think the best argument for twisting is that it is convenient to keep the two wires together and parallel. I see heaters that are super tightly twisted and can’t understand why it would be better then loosely twisted.
There is a happy place in between super tightly twisted and loosely twisted.
https://audiouniversityonline.com/twisted-pairs/ (https://audiouniversityonline.com/twisted-pairs/)
-
The easiest method to do it manually would be with lockwire pliers. They're designed to twist two wires together.
-
I always do it like I did last summer.
-
lockwire pliers
I DO NOT miss those days!
bloody fingertips!! getting jabbed a couple times just snipping n striping the lock wire, couple more jabs re-wiring :cussing:
-
Ello. I always wondered about using 2 conductor shielded cable for heater wires. Any reason why this isn't feasible other than having to ground it? If I'm hijacking your thread let me know and I'll start a new one.
-
2 conductor shielded cable for heater wires?
There's nothing to say that you can't do this, but it would be impractical.
The most common shielded wires in our amps are RG-174 and RG-316, both of which feature a core conductor consisting of tiny steel wires plated with copper. They are not designed to carry the amperage required for heaters. Yes, you could probably get away with it, but what would be the point ? Yeah, yeah, I'm sure there is a shielded wire available that could pass the current . . .
I do use my drill to twist pairs of stranded 22AWG moderately, and it works fine for me. Very simple and it has been quite reliable.
-
What about the 18ga red/black zip wire Doug sells?
About half way down the page here: https://hoffmanamps.com/MyStore/perlshop.cgi?action=template&thispage=WireCable&ORDER_ID=694633395 (https://hoffmanamps.com/MyStore/perlshop.cgi?action=template&thispage=WireCable&ORDER_ID=694633395)
-
once I stole this concept from Sluckey and others, I never looked back.
filament induced noise is all about sensitive signals getting to close, not the twist.
the chassis itself acts as a shield when you tuck 'em in the corner
I suggest to consider flipping the sockets 180, doing so can make the heater wire routing more compact and separated from signal wiring, eg (https://i.ibb.co/0c2Nq7v/40-AA0914-DD95-42-D7-AC6-C-E639-A771-F91-C.jpg)
-
I've used several different methods to wire filaments. I can't hear any difference in any of these methods...
http://sluckeyamps.com/magnatone/M10A_guts.jpg
http://sluckeyamps.com/hammond_2/big_guts.jpg
http://sluckeyamps.com/smoky/3.jpg
http://sluckeyamps.com/warbler/w_06.jpg
http://sluckeyamps.com/VAC15/big_guts.jpg
http://sluckeyamps.com/phoenix/p11_big.jpg
http://sluckeyamps.com/supro/supro_02_big.jpg
-
@PRR:
1 twist per inch is roughly a good number.
Just so I'm clear, are you talking about CAT6 cable here, or guitar amps? ...
Yes.
... I've seen recommendations ... But you seem to be suggesting that ...
What is the point of twisting? What did PRR say about CAT5, CAT6 cables & the research put into them? What is the twist-rate on CAT5 or CAT6 cables?
-
Looks like maybe 2 -3 twists per inch. 23 ga copper wire.
-
I have been a loyal tight twister from day one. That being said Ihave a amp that is dead quiet with one heater wire and the chassis as return, when I posted this amp on another forum to point out the heaters as quiet a creditable member pointed out that heater wire hum is overstated and lots methods are fine. As in twist tight don’t twist and it all good. So whatever suits seems to work just fine. I think sluckey having various styles hints at this.