Best guitar cable tester? How to test for the best cable?

[JFrankParnell]

Hey hey,

I've seen those little cable tester boxes, at GC, but seems like they just test continuity? Maybe they do better than that, detecting 'crapacitance' in some way? But still, what constitutes a 'green light' for that box, as opposed to a 'yellow light'?

What if I have two cables that test 'green' but want to know which is really better? What is the test, for that?

My basic curiosity, at the moment, is should I buy a couple medium-high-end cables and compare them to the cheap no-names I've been using? I have been using a DI box, sent to a mixer, looking at the meter on the mixer, comparing cords. I was able to weed out a bad cable.

tanx,
JFP

pps, is there a tester, to test those cable testers?

[newey]

I dunno about those particular boxes, but if all you need to test is continuity (i.e., is it any good or is it shorting out), then your multimeter (which you already have, presumably) will do just as well.

If you want to know capacitance, you'll need an LCR meter. If the box shows capacitance instead of just continuity, then it might be a deal, as LCR meters tend to be pricey and you probably won't use most of its functionality for basic guitar wiring.

[JohnH]

I have one of these, which is a multimeter with ranges for capacitance and inductance:

Jaycar - QM1548 multimeter



That is from our Australian electronics chain, but I'm sure similar is available elsewhere. Its $65AU, which is about $50 US, and probably less from an overseas supplier.

Its not an official LCR meter, and most references say that 'multimeters' that have capacitance ranges do a poor job, since they work by a different method that is not as good a way to make the measurement. But I find this one to be definitely somewhere in the range between 'good enough' and 'quite good'


I used it to measure a couple of nominally 1nF capacitors, and I got a readings of 1.03nF and 1.04nF. This suggests that most likely, both the meter and the caps are reading within about 5% or better.  That value is around what you might expect from a long guitar cord.

Two 10' cords had their capacitances measured, at 0.43nF and 0.48nF. Very credible readings.

With inductances, its harder to be sure of how accurate the readings are without known references. But a couple of pickups that I have on my Strat offer inductance readings of 2.4H, which is on-spec according to Fender. So I think the meter is working well enough, and this is a useful number for comparing pickups since it has the greatest effect on tone.
 

[JFrankParnell]

Ok, John's meter is quite a bit more affordable than the LCR's out there, for sure.

Two 10' cords had their capacitances measured, at 0.43nF and 0.48nF.

What capacitance numbers are we looking for in terms of guitar cables? What is the range of 'crappy'/'ok'/'great'/'really great, but cant really be distinguished from good'? 10' is too short, for me; I usually play with 15'

[ashcatlt]

I think JohnH is probably better to give actual numbers, but I think you should be looking at capacitance/foot so that you're comparing apples to apples. You should get different readings when measuring cables of different lengths.

It might be obvious that the cable should be unterminated at both ends. Well, okay, the meter technically does terminate the one end, but neither end should be plugged into anything.

Less obvious perhaps is the fact that the cable should probably be stretched out as straight as possible, and preferably some distance from any other conductors. A coiled cable should read a different capacitance than when stretched out, and a tighter coil should read different than a looser coil, and it's easier to "match" stretched straight than to try to coil two cables exactly the same.

[JohnH]

I think about 40pF per foot is average-ish and fine in a good cable. I like the sound of my decent cables which are about that, based on them being 10'. If you liked the clarity of that, but use 15' for practical reasons, you should be able to find that based on 20 or 25pF per foot. Not all makes declare the numbers. One that does is Lava cable

[JFrankParnell]

Aug 17, 2016 20:34:09 GMT -5 JohnH said:

I think about 40pF per foot is average-ish and fine in a good cable. I like the sound of my decent cables which are about that, based on them being 10'. If you liked the clarity of that, but use 15' for practical reasons, you should be able to find that based on 20 or 25pF per foot. Not all makes declare the numbers. One that does is Lava cable

Are you saying that a 40pF cable, at 10' is about the same as a 20-25pF at 15'? 40 x 10 = 400, 26.7 x 15 = 400.. so yeah, seems like you do have to get a pretty good cable, if youre going to use a 15'.

here's mogami specs: 47 or 39 www.parts-express.com/pedocs/specs/mogami-w2319-high-impedance-23-awg-guitar-instrument-signal-cable-specifications.pdf

d'adarrio (planet waves), at 28: daddario.com/pwProductDetail.Page?ActiveID=4115&productid=18&productname=American_Stage_Instrument_Cables


From this article: www.shootoutguitarcables.com/guitar-cables-explained/capacitance-chart.html
I made this sheet (convert to pf/foot. Because 'Murica) docs.google.com/spreadsheets/d/175fg69vMSKve64jzTBbZ0Ue9ZTyT0yUO2zUvpINekVk/edit?usp=sharing

Also, there's people out there *preferring* the high capacitance cables, to knock back the brightness a bit. Of course, they could probly turn their treble knob down a notch, too

I got these conquest (35pf/ft) cables a while back, and except for one of the plug connections breaking, has been ok for the price. $24. Except for microphonics: if you have the gain way up, you can definitely hear it, slapping on the floor.
www.amazon.com/gp/product/B007GGA7WW/

[coradias]

Hi....you can use Fluke multimeter. Its not an official LCR meter, and most references say that 'multimeters' that have capacitance ranges do a poor job, since they work by a different method that is not as good a way to make the measurement. But I find this one to be definitely somewhere in the range between 'good enough' and 'quite good'.

pcb assembly firm

[reTrEaD]

Mar 6, 2018 10:04:33 GMT -5 coradias said:

Hi....you can use Fluke multimeter. Its not an official LCR meter, and most references say that 'multimeters' that have capacitance ranges do a poor job, since they work by a different method that is not as good a way to make the measurement. But I find this one to be definitely somewhere in the range between 'good enough' and 'quite good'

Hello, coradias

to GN2

Fluke makes several meters that can measure capacitance. To which one, are you referring?

[sumgai]

Full disclosure: I used to work at Fluke Industries, long before they moved to Everett, WA. Thus anything I say cannot be taken as unbiased, and therefore I will not say anything on this topic.

But JFrank has a point - using a multimeter (of any stripe) is much more difficult due to having to hold the leads on two separate plugs, and not allow them to touch any adjacent pins - that's tough to do. Better to use a tester made for the job. Although if one wants/needs to know the approximate capacitance of a cable (per foot or the whole thing), then the price goes up accordingly.

Even so, JFP has the right idea - if you need to adjust for loss/gain of brightness, just turn one (or more) of the controls in the signal chain to compensate. As the cook books all say, adjust the proportions to suit your taste.


OK, one more thing - if you are afraid of cable capacitance, integrity, durability, or anything else about cables, then you are in the market for an RF cable. 'Nuff said.


HTH




sumgai

[reTrEaD]

Mar 7, 2018 15:41:11 GMT -5 sumgai said:

But JFrank has a point - using a multimeter (of any stripe) is much more difficult due to having to hold the leads on two separate plugs, and not allow them to touch any adjacent pins - that's tough to do.

SPOILER: Click to show

{It could be difficult, unless you are Nutz.}

[sumgai]

Ya know, somehow I got the idea, somewhere, that I was speaking in terms of more than 2 conductors. If'n it's nothing more than a standard, dirt simple, guitar cord/cable, then reTrEaD's appliance above will work just fine. It shouldn't add any capacitance to the measurement, but if you're a real stickler, then make your own. You can buy the two ends from various locations in the web, and for the connecting short length of cord, use zipwire (2-conductor lamp cord), available at most hardware stores, etc. - it will have no appreciable capacitance or resistance.

Nice find, reTrEaD.





sumgai

[JFrankParnell]

Oh, I didnt have a problem, checking simple continuity. All you need for that is a guitar and amp: if there is any sound, coming thru, there is continuity. Then, you just wiggle things, to see if that continuity is intermittent

[b4nj0]

Love it, except for (eg) a dynamic microphone connected to a phantom powered system. There you'd have a coupling cap to block the DC so no DC continuity, but for your wonderful electric guitar KISS tech. solution it holds fast.

e&oe...

[newey]

Oh, I didnt have a problem, checking simple continuity. All you need for that is a guitar and amp: if there is any sound, coming thru, there is continuity. Then, you just wiggle things, to see if that continuity is intermittent

True, but sometimes you have to be able to isolate the cord as the cause of the problem, as opposed to a problem inside the guitar or perhaps the amp. You can swap out cables, of course, but only if the second one is "known good".