• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

hookup wire options

I am just about ready to build my budget tube amp, but still did not buy the hookup wire. I am ready to spend around $100 for hookup wire if it is justified. All the components I have chosen so far are good but not the best of their class. Any suggestions for ...

- Solid or Stranded
- Pure Silver ?
- Gauge ?
- General hookup wire (shielded?)
- The signal cable (shielded pair?)
- Ground bus

Do you use the same cable everywhere in the circuit ?
Manual shielding ?
Is CAT 5 or 6 a good candidate ?

There are a lot of posts about interconnect cables but I did not find a good source of information for hookup wire.
 
Use shielded wire for inputs, RG174 mini coax works well. There was a recent thread here on the same subject you may want to check out. Stranded teflon wire should suit your needs. Its a bit stiffer than regular PVC jacket wire and won't melt from soldering. 22 or even 24 AWG will be enough for short runs in a chassis. My last few amps were built with wire from ebay. Something like 6 different colors in 50 foot lengths for a few bucks.
 
I use plenum rated Cat 5 (solid core 24g teflon dielectric, regular Cat 5 is PVC) for signal path. These guys are a good source to get it by the foot:

http://www.takefiveaudio.com/mall/shopdisplaycategories.asp?id=8&cat=Cable/Wire

$3 worth will keep you busy for awhile, as you get 8 strands per foot. The twisted pairs are handy too, as they reject noise fairly well. As it isn't an expensive design, I'd use something cheap for the power supply. You can find plenty of options at your local home improvement store. If you want to get fancy, Take Five has plenty of options. I can't imagine that the hook up wire quality will make much difference unless you are building something quite expensive and putting it in a very high end system. I'd put every part higher on the upgrade list than hook up wire. If you really want to spend bucks on wire, spend it on your IC's and speaker cables.

pj
 

itsmejto

Member
2008-03-02 6:55 pm
Oh my, what about current ratings, voltage ratings and important also, heat ratings, all play a big part in tube amps.
I use standard #18 copper solid pvc, rated to 100+C and where required, 1000vdc rated which hs a slightly fatter insulation.
Teflon mini tubing is nice for cap and res. wire insulation.
Check out your tube parts supply and use what they recomend/sell.
Using any old wire from a stripped cat5 cable is asking for trouble inside a tube chassis.
 
astouffer said:
Use shielded wire for inputs, RG174 mini coax works well. There was a recent thread here on the same subject you may want to check out. Stranded teflon wire should suit your needs. Its a bit stiffer than regular PVC jacket wire and won't melt from soldering. 22 or even 24 AWG will be enough for short runs in a chassis. My last few amps were built with wire from ebay. Something like 6 different colors in 50 foot lengths for a few bucks.


I must be lucky and live in a are that is relatively free of RF hash but I have never needed to shielded signal wire. I just use 22 guage solid core copper with teflon insulation. "Oxygen free", "long crystal" solid core copper of course.
 
Code:
quote:
Originally posted by itsmejto
Using any old wire from a stripped cat5 cable is asking for trouble inside a tube chassis.
is it?

What troubles do you have as an example?


I would worry about voltage rating as the few references I just googled seem to say it's only 300 volts.
 
hotbottle said:
Code:
quote:
Originally posted by itsmejto
Using any old wire from a stripped cat5 cable is asking for trouble inside a tube chassis.
is it?

What troubles do you have as an example?


I would worry about voltage rating as the few references I just googled seem to say it's only 300 volts.
and that presumably is core to core.
That is equivalent to 150V core to skin.
Just ensure that where Cat5 is used to never exceed 150V core to skin.
Most will be in mid air. All signal level requiring twisted pairs will be much lower than 300V core to core.
 

itsmejto

Member
2008-03-02 6:55 pm
stripped down cat5 wire is not on my list, after reading others comments, it never will be, and there is also the flimsy insuation, mechanically dangerous as well as not heat or voltage rated.
Get wise, use the right stuff or some day you will wish you had.
They didn't use that fat rubber/cloth wire for nothing.
Maybe if you parallel all your cat5 wires you could make an extension cord for yer drill !!!!!! hmmmm ....
 
You guys are right about CAT5 or CAt 6 not beeing suitable for chassis wiring. Here are the specs from ADC CAt6 cables:

Conductor DC resistance (maximum): 9.38 Ù/100 meters (28.6 Ù /1000 feet) @ 20 °C (68 °F)
DC resistance unbalance (maximum): 2%
Mutual capacitance (maximum): 5.6 nF/100 meters (17 pF/ft)
Operating temperature (maximum): 75 °C (167 °F)
Operating voltage (maximum): 300 VDC
Worst case cable skew: 25 nS/100 meters (25 nS/328 ft)
Nominal velocity of propagation: 73%

low resistance, low capacitance, but can't use over 300V :(

I am tempted by this guy's offer ...

http://cgi.ebay.com/99-999-5n-Pure-...ryZ64591QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

10ft will cost me around 80$ including shipping and customs.
 
I've been using stranded Cat-5 cable in some of my low voltage projects recently, other than the low melting point when soldering I've had few problems.. It's very flexible and the insulation has a relatively low dielectric constant. I don't use it anywhere where voltages are higher than 30V or so.

Apparently it makes good interconnects and speaker cable too - a number of my friends swear by it.

It's pretty decent stuff as long as you don't melt the insulation, and in normal use the insulation temperature rating is high enough that it should not be an issue. (The stuff I am using is UL approved and carries an 85 C rating.)

Adaptive reuse keeps the stuff out of landfills and the scrappers from burning it (air pollution!!) to recover the copper.

My actual favorite is Kimber TCSS stranded high purity copper wire with Teflon insulation, but it is inflexible and expensive. (Michael Percy sells it by the foot in 5 different colors.)

I use 14ga Romex for ground buss.