What point to point wire to use?

[simonl8353]

Hi all,

my first project is a push/pull Dynaco circuit with a 5AR4 Rectifier and 6V6 output tubes. I have all the components except the point to point wire. I have been told that Olex 1mm twin and earth is very good (the stuff used in household lighting, peel off the outer white sheath and use the red and black wires inside). Does anyone recommend anything else?

Thanks in advance, progress photos attached.

[AndrewT]

I use tinned & insulated 0.6mm diam solid core copper. Not tin plated, but solder dipped
Comes on 100m reels and many colours. Great for twisted pairs and twisted triplets and twisted star quads.
I have used some insulated silver plated copper solid core in the past but did not detect any differences.

[DF96]

Is that microphone cable you have used for heater wiring? I would use mains cable inners for that, tightly twisted to reduce net loop area. You seem to have large loops at some valveholders, so may get a hum problem.

[indianajo]

New wire prices have gone through the roof with ROHS law and the disappearance of some suppliers. In Aust, you don't need silver plate ROHS compliant wire , so I would look at electronicsurplus.com (New York) or your local equivalent. I found some 18 ga teflon insulated in 20' rolls at ES I use for some things. Make sure wire you use is rated 600V. I also use 24 ga wire for some things in tube amps, both red and black PVC ins tinned in solid core (25 year old old 100' Belden stock) and white and blue Alpha stranded sliver plate with teflon insulation. The teflon doesn't split off as PVC does if you have trouble getting the solder to adhere, and if you wave your iron around in an uncontrolled fashion while you look for the next tool or part, there will be less repair work. The blue 24 ga teflon Alpha wire was $.60 a foot in hundred foot rolls, probably the last time I buy ROHS wire. triodeelectronics.com has (illinois) 20' twists of varied colors of fabric insulated 600 V wire, and tubesandmore.com (arizona) has little rolls of 600v hookup wire. Neither is ROHS compliant.

[simonl8353]

Originally Posted by DF96

Is that microphone cable you have used for heater wiring? I would use mains cable inners for that, tightly twisted to reduce net loop area. You seem to have large loops at some valveholders, so may get a hum problem.

Guilty, it is Mic cable, I was hoping being taped to the alloy lid (which it is now, but not in photo) would help eliminate the hum, well, thats the plan

[simonl8353]

Originally Posted by AndrewT

I use tinned & insulated 0.6mm diam solid core copper. Not tin plated, but solder dipped
Comes on 100m reels and many colours. Great for twisted pairs and twisted triplets and twisted star quads.
I have used some insulated silver plated copper solid core in the past but did not detect any differences.

What is the brand and where can I get some from?
Thanks

[simonl8353]

Originally Posted by indianajo

New wire prices have gone through the roof with ROHS law and the disappearance of some suppliers. In Aust, you don't need silver plate ROHS compliant wire , so I would look at electronicsurplus.com (New York) or your local equivalent. I found some 18 ga teflon insulated in 20' rolls at ES I use for some things. Make sure wire you use is rated 600V. I also use 24 ga wire for some things in tube amps, both red and black PVC ins tinned in solid core (25 year old old 100' Belden stock) and white and blue Alpha stranded sliver plate with teflon insulation. The teflon doesn't split off as PVC does if you have trouble getting the solder to adhere, and if you wave your iron around in an uncontrolled fashion while you look for the next tool or part, there will be less repair work. The blue 24 ga teflon Alpha wire was $.60 a foot in hundred foot rolls, probably the last time I buy ROHS wire. triodeelectronics.com has (illinois) 20' twists of varied colors of fabric insulated 600 V wire, and tubesandmore.com (arizona) has little rolls of 600v hookup wire. Neither is ROHS compliant.

Thanks, I ordered some from tubesandmore. I appreciate the help from everyone. Great site this.

[DF96]

AC heater wiring can cause hum by two mechanisms:
1. magnetic induction - solution is to tightly twist the cable and be careful about minimising loops at the valveholders.
2. capacitive coupling - solution is tight twisting and also balanced (CT) supply.

Using an audio screened twisted pair cable (if it can cope with the current draw) may help with the second issue, but may have insufficient twisting for the first. The most critical place is near the valveholders, as that is where the heater wiring is likely to be nearest to other components, yet here the audio cable gives no advantages at all as the inners have to emerge from the screen.

[AndrewT]

Originally Posted by simonl8353

What is the brand and where can I get some from?

most of my current stock is Rapid online. But it's just copper and PVC, what matters who makes it?
I use a lowish voltage rating because I don't work with valves.

[KimmoSWM]

I´d use some Silver Plated Copper with Teflon Insulation in various AWG for different purposes. That is good for soldering and sounds also nice. Also some OCC copper is very nice but is bit more expensive though.

Good places to look at are Partsconnexion (Canada) or Hificollective (UK).

Also industrial grade copper with PVC insulation goes if you´re not that in conductors. Just check the voltagetolerance.

-Kimmo-