Cables: Which Are Best?

In this blog post, we are going to take some different cables into the lab, and look at how they stack up in terms of some basic, measurable numbers.

In our test, we have seven different cables varying in price from less than $6 to over $250. There are a variety of different core materials and jack plating’s, as well as the same cable with different lengths, so we can compare the impact just of the length of the cable.

Contenders

Neewer. This was the lowest cost 10’ guitar cable I could find on Amazon Prime at the time of purchase. I paid $6.95. The cable has a braided Tweed style cloth jacket and large jack plugs. The tip of the jack plug is gold colored, although I could not tell if it is actually Gold plated. The sleeve of the jack appears to Nickel.

Rapco Horizon. The Horizon Standard is available at Guitar center for $7.50. I took this one from our collection in the lab. This cable has 116 reviews on Musicians Friend, so I imagine it is a very popular low cost, no frills instrument cable.

Quantum Audio Designs. The first of the Oxygen Free Copper cables. This one was purchased from our local music store for about $15. It has heat-shrink over the jack and first few inches of the cable.

Best-tronics Pro Audio. We tested a 10ft TRS cable. TRS cables are sometimes used with active pickups, dual magnetic/Piezo, and other types of guitar that require the additional conductor. The cable utilizes OFC conductors and Switchcraft ¼ Nickel jacks. Best-tronics will custom make cables to order to any length. Price is around $24 for TRS 10’.

Kirlin Stage. The Kirlin Stage is described as ‘exclusively designed for live performance’ The 18 AWG OFC conductor is thicker than the others on the list. The large metal jack plug has gold plated contacts, and a black painted metal body. The Literature lists a couple of China Patent numbers: ZL 201230626606.8, and ZL201320086667.9, if you want to try looking them up. Price is $25 at Musicians Friend.

Zaolla Silverline. The Silverlines are the only Silver cables that we tested here.
They are described by Zaolla as using a mixture of Silver and Copper conductors: ‘all Zaolla Silverline instrument cables feature a solid Silver center conductor and an enamel coated, stranded copper ancillary conductor in a unique hybrid configuration’. The Jack plugs are listed as having both Rhodium and Silver plating layers. Similar to Best-tronics, Zaolla can build cables to custom lengths on request. We tested a 15’ cable and a 2’ cable from the same line. A 15ft cable is priced on zaolla.com at $254.95, and a 10’ at 199.95.

Tests

A cable connected to a magnetic guitar pickup creates an RLC 2nd order low pass filter. This creates a small boost to the signal at the resonant frequency, and then gradually attenuates the signal at higher frequencies past that. By adjusting the amount of capacitance and resistance in the circuit, you can control the center frequency and slope of the filter.

Since the resistance and capacitance of your guitar pickups, tone and volume controls, as well as the number and length of cables all work together to impact this, every rig is going to be different. This is potentially even true in the same guitar. If it is a multi-pickup guitar where the pickups have different inductance and resistance, just switching between pickups will change the characteristics of the filter.

With this in mind, I measured the resistance and capacitance of the cables and jack plugs themselves as best as I was able. If you characterize the rest of your circuit by looking up the numbers or measuring your guitar pickups, you can then plug these numbers into an online RLC filter calculator (or do the math yourself if you prefer) and predict the effects.

Measurements

All measurements were taken at 68 degrees F. The cables were all kept in the same room as the measuring equipment for at least five hours, and the measuring equipment was left on for at least one hour before for temperatures to stabilize. I measured the resistance of each cable from tip to tip, and sleeve to sleeve. I measured the capacitance of each cable from tip to sleeve at each end. The results are shown in the table.

Results

The biggest single factor impacting change was the length of the cable. Total resistance of the cable assembly (including jacks) is reduced by more than half on the 2ft Silverline compared to the 15ft. Capacitance was reduced almost six times, which is directly proportional to the change in length within the margin of error.

The 15 ft Silverline had the lowest resistance on the signal conductor at 0.013 Ohms/ft. The 18 AWG Kirlin was close behind at 0.016 Ohms/ft. The 2ft Silverline measured a higher resistance per foot, but this was most likely due to the contact resistance at the measuring point on the jack making up a greater proportion of the number on the short cable. As cables get longer, the resistance of the cable becomes much more significant than the resistance of the jack.

The Horizon had the greatest resistance on the tip. At 24AWG compared to 22AWG for the Best-tronics and 18AWG for the Kirlin, this is not unexpected. The thinner wire should have a greater resistance and our measurements bear this out. The Horizon also had an order of magnitude higher resistance on the sleeve. The cable was not new, and was taken from our demo room, it possibly had some damage, which just goes to show that it is worth testing your cables on a regular basis, even if they appear to be working.

The resistance of the cable however, generally makes up only a small percentage of the overall resistance of the circuit. With the pickups, volume, and tone controls usually being in the hundreds of Kilo Ohms range. The capacitance of the cable usually has a more dramatic impact on the audible tone. Here again, the best way to reduce the capacitance of the cable is to shorten it. The short 2ft Silverline measured just 84pF, compared to 969pF for theNeewer which was the worst performing in our capacitance test. Calculating a theoretical pickup configuration, that moves the cutoff frequency of the filter from 12KHz to 3.6KHz, which would be a noticeable difference.

The lowest measured capacitance per foot of all out cables was the Quantum Audio Designs at 25pF/ft, followed by the Silverline 15 at 33pF/ft. and the Silverline 2 and Best-Tronics both at 42pF/ft.

Conclusions

Shorter is better. Although it’s obviously not practical to use a 2ft guitar cable, minimizing the number of cables and keeping down the length helps. Use as short a cable as possible from your guitar, and use a buffer first in line if at all possible. If your environment requires a really long guitar cable, consider using active pickups, or a wireless system instead.

The very low cost cables in our test did not perform great. The Neewer had a much higher capacitance than the others which would be audible in most guitar setups. The Horizon had a higher than normal resistance reading on the sleeve (which may have been due to some damage).

The Zaolla Silverline was the most expensive cable in our test, and had the lowest tip resistance and the second lowest capacitance so there’s no doubt it scored well. The Silverline was also noticeably lighter than the other cables. The 18AWG core in the Kirlin helped it turn in a low resistance measurement very close to the Silverline, although capacitance of the Kirlin was not great.

From $20 up, the differences between the expensive and mid-priced cables were small, especially in capacitance where it most matters. At around $20 ea, the mid-priced Quantum and Best-Tronics cables were close to or better than the highest price cable.