Thank you Gene, Hugo & Co.

[<eargiant]

Hello all, first post here. I primarily came to Audioholics because I like the fact (scientific/engineering) based testing and also because it seems that this site does not tolerate the "snake oil BS" in order to get advertising dollars. Kudos to you guys.

Anyway, I've read Gene's Cable guides and recently watched Gene & Hugo's videos on Cables and it gave me an idea. Gene explained how combining two of the same AWG wires reduces the gauge by 3. I had hundreds of feet of (what I believe is) high quality 16 AWG cable that I was not using due to it's high gauge. Since I learned that I could combine them and effectively get a 13 AWG wire, that's what I did. Based on Gene's chart I'm OK with 13 AWG for my distance down to 4 ohms ( I think my speaker only dip down to 4.7ohms).

Here's my question: How do the Resistance, Capacitance and Inductance numbers change when you double-up on cable? Is there a formula to calculate that? I realize that I'm OK with the 13 AWG but I'm curious to know the new specs of my doubled-up cables.

Here's the spec sheet of the cable I have (manufactured by Quabbin Cable):
https://www.quabbin.com/sites/default/files/datasheets/3130-06.pdf

Based on this chart, Quabbin says it is the equivalent of Belden 8471:
https://www.quabbin.com/sites/default/files/publications/Quabbin_Equals_2012.pdf

Here's the Belden 8471 spec sheet:
http://www.belden.com/techdatas/english/8471.pdf

Here's how I ran the Quabbin 3130:


One combined wire feeds POS and one combined wire feeds NEG


One combined wire feeds POS and one combined wire feeds NEG


I twisted the left & right speaker wire separately

Any input would be appreciated.

Thanks in advance.

 

[gene]

You did a good thing with these cables. Twisting them together helps eliminate noise pickup and also keeps the conductors in close proximity to reduce inductance. You may want to tape the conductors all together every few feet to keep all of the conductors closely spaced together.

see: https://www.audioholics.com/audio-video-cables/calculating-cable-inductance-of-zip-cord

Calculating inductance/capacitance gets tricky and not worth it unless you just love the maths. I may have to configure a cable like you did and pull some measurements to see what you got. It would make for a good article for sure.

For more DIY Speaker cables, check:
https://www.audioholics.com/gadget-reviews/diy-speaker-cable-faceoff

 

[<eargiant]

You did a good thing with these cables. Twisting them together helps eliminate noise pickup and also keeps the conductors in close proximity to reduce inductance. You may want to tape the conductors all together every few feet to keep all of the conductors closely spaced together.

see: https://www.audioholics.com/audio-video-cables/calculating-cable-inductance-of-zip-cord

Calculating inductance/capacitance gets tricky and not worth it unless you just love the maths. I may have to configure a cable like you did and pull some measurements to see what you got. It would make for a good article for sure.

For more DIY Speaker cables, check:
https://www.audioholics.com/gadget-reviews/diy-speaker-cable-faceoff

Thanks for the quick reply, and from the man himself. Glad to hear that I did it properly! The calculations are way over my pay grade so I'll leave that to you guys. I'm assuming that at least the resistance (which I think you say is most important) of my doubled-up cable is less than what's on the spec sheet so that should be a good thing.

The amp I'm currently using has a very high slew rate & high bandwidth and I want to be sure that this cable set-up doesn't cause any issues. I've read that certain cable arrangements can make amps oscillate. I also don't want anything to hold it back-performance-wise.

If you're really interested in testing this arrangement and writing an article I'd be more than happy to send you some of this cable (depending on how much you need) if I have enough. I think it would be pretty interesting to say the least.

 

[mtrycrafts]

....

The amp I'm currently using has a very high slew rate & high bandwidth and I want to be sure that this cable set-up doesn't cause any issues. I've read that certain cable arrangements can make amps oscillate. I also don't want anything to hold it back-performance-wise.

....

Welcome.

What amp do you have with this setup. Naim amps, at least in the past, was sensitive to capacitance loads of cables, goes into oscillation and self destroys.

 

[<eargiant]

Welcome.

What amp do you have with this setup. Naim amps, at least in the past, was sensitive to capacitance loads of cables, goes into oscillation and self destroys.

Thanks for the welcome, happy to be here.

The amp is a fully restored Sansui AU-X1. Due to the high slew rate (260V/usec) and bandwidth (DC-500,000Hz) the early production models were known to oscillate and blow the high speed outputs. Luckily, the one I have was a later model when Sansui seems to have sorted out the issue. It was in perfect condition when I acquired this rare beast almost a year ago but I took no chances and had it fully restored by a competent tech (roughly 300 top shelf parts were used). If there's any interest for that kind of stuff here maybe I'll start another thread and post pictures.

I've been running it with the cables as described with three different modern stand-mount speakers for a couple of months with no issues as far as I can tell.

 

[<eargiant]

Welcome.

What amp do you have with this setup. Naim amps, at least in the past, was sensitive to capacitance loads of cables, goes into oscillation and self destroys.

Yes that's it, capacitance. I did some more reading this morning to refresh my memory and you are correct, high capacitance was the issue I had read could potentially cause problems.

Based on the spec sheet, the capacitance of the Quabbin 3130 cable I used is 15 pf/ft (which I believe is considered low) so I guess my question is:

Does the capacitance of a wire increase or decrease when you double it up or does it vary?

 

[KenM10759]

Where are you sourcing the Quabbin cable and why did you choose it? They are just a few miles from me but I'd been unaware that they sold such products. We have a half-dozen wire & cable makers within 10 miles of me, they all seem busy so I should Google all of them to see what they offer. Most are clearly business-to-business only though.

 

[<eargiant]

Where are you sourcing the Quabbin cable and why did you choose it? They are just a few miles from me but I'd been unaware that they sold such products. We have a half-dozen wire & cable makers within 10 miles of me, they all seem busy so I should Google all of them to see what they offer. Most are clearly business-to-business only though.

A few years back I purchased a pair of used speakers and the seller gave me two long runs of this cable which is what he was using with them. It looked like pro-grade tinned copper but the gauge was thinner than what I had so I just stored it and didn't think much of it.

Not long ago I saw Gene's video recommending doubled-up 14/4 cable and a light bulb went off. It made me take another look at this cable to see if I could use it in a similar manner.

The only markings on the cable were these:



I did some research and determined that the E69976 is the identifier for Quabbin Cable. So I sent them a sample of the cable to confirm the gauge and determine the specs and intended application. They got back to me and said that because it had no other markings that it was probably a special order but that it was basically their 3130 which is the spec sheet they sent me (and I posted earlier).





Thanks to what I've learned so far on Audioholics I was able to put what seems to be pretty decent cable to good use. I was a bit concerned that being housed separately (unlike the 14/4 which is all wrapped together) would cause a problem. Thankfully, Gene already confirmed that it's OK the way I did it.

I just want to be sure I'm not overlooking something like changes in capacitance that could be detrimental. If you guys tell me that what I have is a high quality solution for my 20-25 ft run then I'm good. Likewise, I'm open to any suggestions.

Thanks

 

[KenM10759]

Interesting to see a tinned copper cable, one making no (apparent to me) claims of being "OFC" grade copper base. I don't see that used much in speaker cables, but know NOTHING about capacitance, inductance, the meaning of the values for those, and little about resistance.

Man, I need an education. I made speaker cables out of 12 gauge Monoprice CL2 and thought it sounded fine, but just don't know that stuff.

 

[lovinthehd]

Interesting to see a tinned copper cable, one making no (apparent to me) claims of being "OFC" grade copper base. I don't see that used much in speaker cables, but know NOTHING about capacitance, inductance, the meaning of the values for those, and little about resistance.

Man, I need an education. I made speaker cables out of 12 gauge Monoprice CL2 and thought it sounded fine, but just don't know that stuff.

Nothing wrong with what you used. "OFC" doesn't translate to better sound in and of itself. Try this site from a former head guy at McIntosh if you haven't already http://www.roger-russell.com/wire/wire.htm

 

[<eargiant]

Interesting to see a tinned copper cable, one making no (apparent to me) claims of being "OFC" grade copper base. I don't see that used much in speaker cables, but know NOTHING about capacitance, inductance, the meaning of the values for those, and little about resistance.

Man, I need an education. I made speaker cables out of 12 gauge Monoprice CL2 and thought it sounded fine, but just don't know that stuff.

I don't know much about this stuff either. I looked into the "tinned copper" aspect when I was deciding if I should put this cable to use and here's what Quabbin says:

https://www.quabbin.com/tech-briefs/tin-vs-bare

 

[Speedskater]

Getting back to some of the basic questions.

a] Using 4 identical conductors instead of 2:
1] the end-to-end resistance will be cut in half.
2] depending on the cable construction, the capacitance may almost double.
3] depending on the cable construction. the inductance may almost be cut in half.

b] OFC wire.
Not much difference between OFC and regular wire.
Less difference than between a 10 foot and an 11 foot regular wire.

 

[<eargiant]

Getting back to some of the basic questions.

a] Using 4 identical conductors instead of 2:
1] the end-to-end resistance will be cut in half.
2] depending on the cable construction, the capacitance may almost double.
3] depending on the cable construction. the inductance may almost be cut in half.

b] OFC wire.
Not much difference between OFC and regular wire.
Less difference than between a 10 foot and an 11 foot regular wire.

Great!, so far it seems like Gene's video and this site spurred me make a pretty good cable out of something I already had laying around.

So to confirm that I'm on the right track and have a grasp of this:

Is lowering inductance a good thing?

If my new "approx." capacitance is 30 pf/ft (if I double the Quabbin 3130 spec) is that considered a "low" or good capacitance number for what is effectively now a 13 gauge cable?

Thanks for the help.

 

[mtrycrafts]

...

Does the capacitance of a wire increase or decrease when you double it up or does it vary?

As mentioned, two wires in parallel will increase capacitance; the sum of the individual capacitors.

Hopefully that Sansui was redesigned to handle it.
The high bandwidth is a culprit for self destruction from capacitance.

 

[mtrycrafts]

...
Is lowering inductance a good thing?

If my new "approx." capacitance is 30 pf/ft (if I double the Quabbin 3130 spec) is that considered a "low" or good capacitance number for what is effectively now a 13 gauge cable?

Thanks for the help.

Yes, low inductance is good, especially if the amp can handle the increased capacitance caused by the lower inductance. Most can.
Not sure how high is high capacitance for an amp.

 

[<eargiant]

As mentioned, two wires in parallel will increase capacitance; the sum of the individual capacitors.

Hopefully that Sansui was redesigned to handle it.
The high bandwidth is a culprit for self destruction from capacitance.

Yes, low inductance is good, especially if the amp can handle the increased capacitance caused by the lower inductance. Most can.
Not sure how high is high capacitance for an amp.

Thanks for the confirmation. It seems like I'll be OK, I looked up the specs of Belden 5000UE 12 AWG cable and the capacitance is 24 pf/ft. The Belden 5T00UP 10 AWG has a capacitance of 26 pf/ft. and unless I'm reading the specs wrong Canare 14/4 shows a capacitance of 44.5 pf/ft quad wired so at 30 pf/ft for my double Quabbin 3130 it doesn't seem that I'm in any more danger than if I had gone down to Belden's 10 AWG cable. Unless 4 pf/ft makes a big difference for a 25 ft run.

If it does, someone please tell me. I'll just order new wire.

Thanks again

 

[mtrycrafts]

Thanks for the confirmation. It seems like I'll be OK, I looked up the specs of Belden 5000UE 12 AWG cable and the capacitance is 24 pf/ft. The Belden 5T00UP 10 AWG has a capacitance of 26 pf/ft. and unless I'm reading the specs wrong Canare 14/4 shows a capacitance of 44.5 pf/ft quad wired so at 30 pf/ft for my double Quabbin 3130 it doesn't seem that I'm in any more danger than if I had gone down to Belden's 10 AWG cable. Unless 4 pf/ft makes a big difference for a 25 ft run.

If it does, someone please tell me. I'll just order new wire.

Thanks again

That 4 pF is nothing unless you have a very long cable.