An instrument lead cost me over £1k.

pt22

Apologies for the clickbait title. Gotcha! 

I've had a love/hate relationship with my Magnatone Super 15 for nearly two years. On paper and from YouTube reviews, it seemed perfect: 15 watts, excellent MV, marshally-gain structure, compact and lightweight, with features like a dummy load and headphone outs—ideal for late-night jamming. It's a boutique piece and is proper cool to plug into.

However, it didn't sound like the videos. The amp had a piercing mid-honky tone and "gravelly" gain structure at low amplitudes that was unpleasant. Hoping to fix this, I replaced the speaker with a UK Greenback, which helped slightly but didn't solve the issue. I battled with it on and off for nearly two years.

I finally decided to sell the Magnatone and invested in a new amp and cab, spending around £1k, expecting to recoup from the sale. Along side this project, I started rebuilding my pedalboard. As I did I discovered tone suck due to my old cables. A buffer helped a bit, but not enough. Testing pedals and cables, I found my main lead—at least decade-old, 4m+ long cable—was causing the issues.

Switching to a new Mogami cable transformed the sound completely; the mid-honk disappeared and the gain smoothed out. I was shocked; it sems a bad cable was the culprit all along. 

Once I thought to test the cable I had very much expected it to be an issue of dampened high frequencies, but never in a million years did I expect the cable to impact the tone of the amp in that drastic of a way. I thought at most it would sound like a blanket was laid over the amp, but not anything like I experienced.

Has anyone else experienced such drastic tone changes from a cable swap? Can cable capacitance really cause these issues or did I just have a really good day with the amp yesterday and my ears are playing tricks on me?

Revolutions

Thanks for sharing this. It’s actually something I’ve been thinking about testing myself. Since getting a Marshall SV212 I really don’t like something in the tone of my amps, & want to check it’s not my pedalboard causing something weird before thinking about replacing the speakers.

Plectrum

All the ones I've had fail have been at the joint with the jack plug.

maharg101

Yep. Always worth swapping leads out to see what changes.

prowla

Cables can have a significant impact on sound; two items in particular are:

• Shielding: A cable is like an aerial to pick up external signals, so shielding it can reduce/eliminate the issue.
• Capacitance: A guitar's tone control is a capacitor between the signal and gnd connections; a capacitor is two lengths of foil in parallel with an insulator between, which bleeds off higher frequencies; the foils are wrapped into a cylinder so they will fit into a compact space. A cable is a length of wire carrying the signal with a shield around it connected to gnd, with an insulator between; the cable is typically run in a straight line. Hey, that's a capacitor!, so a cable is a tone control. Different cable structures may alter what frequencies they affect, therefore different cables can sound different (and different lengths of cable).

Further considerations are:

• Inductance: Coils and twists in a cable can cause inductance, which also impacts frequency response: inductors bleed away lower frequencies, so pretty much the oppositre of capacitors.
• Cross-talk: Coiling a cable will put the signal wire repeatedly next to itself; this can cause sonic effects.
• Physical effects: Daft as it may sound, the construction and materials of the cable can affect the sound; the company who manufacture my Hi-Fi have a machine to shake their cables at the end of production and even recommend massaging them periodically.
• Faults: Solder joints, broken fibres, dirty connectors can impact the quality of the signal being transmitted from guitar to amp.
• Impedance: guitars, being voltage generators like to have a low output impedance going into a high input impedance at the amp end; a buffer may help this.
• and many more...

In summary, the cable may have a frequency response.

I guess it's possible to find yourself in nerdy-land quite quickly if you think about cables!

Sporky

Inductance and cross-talk in shielded guitar cables are both negligible. 

ICBM

Sporky said:

Inductance and cross-talk in shielded guitar cables are both negligible. 

Yes, and so is resistance - all far too small relative to the values for either the source or load for it to make any difference.

Capacitance on the other hand is very much in the range where it will make a noticeable and even quite large difference, especially with long cables - including coiled ones, which are actually around 3-4 times the unstretched length.

A honky midrange tone could be just a cable with very high capacitance, although a fault might do that too - the type of cable with a semi-conducting shield layer is prone to this if the layer either touches the solder joints at the ends, or the cable gets crushed or kinked and the insulator splits.

Kittyfrisk

prowla said:

Cables can have a significant impact on sound; two items in particular are:

• Shielding: A cable is like an aerial to pick up external signals, so shielding it can reduce/eliminate the issue.
• Capacitance: A guitar's tone control is a capacitor between the signal and gnd connections; a capacitor is two lengths of foil in parallel with an insulator between, which bleeds off higher frequencies; the foils are wrapped into a cylinder so they will fit into a compact space. A cable is a length of wire carrying the signal with a shield around it connected to gnd, with an insulator between; the cable is typically run in a straight line. Hey, that's a capacitor!, so a cable is a tone control. Different cable structures may alter what frequencies they affect, therefore different cables can sound different (and different lengths of cable).

Further considerations are:

• Inductance: Coils and twists in a cable can cause inductance, which also impacts frequency response: inductors bleed away lower frequencies, so pretty much the oppositre of capacitors.
• Cross-talk: Coiling a cable will put the signal wire repeatedly next to itself; this can cause sonic effects.
• Physical effects: Daft as it may sound, the construction and materials of the cable can affect the sound; the company who manufacture my Hi-Fi have a machine to shake their cables at the end of production and even recommend massaging them periodically.
• Faults: Solder joints, broken fibres, dirty connectors can impact the quality of the signal being transmitted from guitar to amp.
• Impedance: guitars, being voltage generators like to have a low output impedance going into a high input impedance at the amp end; a buffer may help this.
• and many more...

In summary, the cable may have a frequency response.

I guess it's possible to find yourself in nerdy-land quite quickly if you think about cables!

Shaking & massaging certainly works for me. No idea if it helps with cables though...

Rowby1

Same goes for speaker cables too. Can have a dramatic effect. 

TTBZ

Yeah, sort of had this but with pedals rather than cables. I used to really struggle with my SG and sustain/sounding choked and weak compared to other guitars. Got rid of my Vox wah that was apparently true bypass modded and it immediately felt way better. Still had less sustain etc, but the difference was less drastic between guitars than before. 

Keefy

Some cables have a semiconducting layer next to the screen. It needs to be stripped back further than the insulation because if the signal conductor comes into contact with it, all sorts of weird and unpredictable shit can happen to your guitar sound.

Boromedic

I tend to find, if my sound is suffering or different, or there's a shift from previous tones, that I'll go direct into the amp and then check from there. If guitar straight in sounds good again, I'll go through my board and see where the culprit is. Having a switcher helps with this and I can easily jumper the midi effects out of the loop as well. Doesn't happen often, had it recently with one pedal where a cable cap had unscrewed and had a dodgy ground. Easy enough to find once I'd ruled out guitar and amp.

prowla

Sporky said:

Inductance and cross-talk in shielded guitar cables are both negligible. 

ICBM said:

Sporky said:

Inductance and cross-talk in shielded guitar cables are both negligible. 

Yes, and so is resistance - all far too small relative to the values for either the source or load for it to make any difference.

Capacitance on the other hand is very much in the range where it will make a noticeable and even quite large difference, especially with long cables - including coiled ones, which are actually around 3-4 times the unstretched length.

A honky midrange tone could be just a cable with very high capacitance, although a fault might do that too - the type of cable with a semi-conducting shield layer is prone to this if the layer either touches the solder joints at the ends, or the cable gets crushed or kinked and the insulator splits.

Aye - I just dropped into nerdiness and thought I should mention them for completeness.

pt22

Boromedic said:

I tend to find, if my sound is suffering or different, or there's a shift from previous tones, that I'll go direct into the amp and then check from there. If guitar straight in sounds good again, I'll go through my board and see where the culprit is. Having a switcher helps with this and I can easily jumper the midi effects out of the loop as well. Doesn't happen often, had it recently with one pedal where a cable cap had unscrewed and had a dodgy ground. Easy enough to find once I'd ruled out guitar and amp.

Totally, and I had done that thinking no way is the cable possibly having that type of impact on the sound. It’s gotta just be the amp! It took me nearly 2 years to piece this all together. Smh. 

TeleMaster

I've never paid too much attention to leads really. What leads are recommended? 

Boromedic

pt22 said:

Boromedic said:

I tend to find, if my sound is suffering or different, or there's a shift from previous tones, that I'll go direct into the amp and then check from there. If guitar straight in sounds good again, I'll go through my board and see where the culprit is. Having a switcher helps with this and I can easily jumper the midi effects out of the loop as well. Doesn't happen often, had it recently with one pedal where a cable cap had unscrewed and had a dodgy ground. Easy enough to find once I'd ruled out guitar and amp.

Totally, and I had done that thinking no way is the cable possibly having that type of impact on the sound. It’s gotta just be the amp! It took me nearly 2 years to piece this all together. Smh. 

Yeah, I have 4 good cables so I always try another known good cable around, it's all trial and error though isn't it. Bloody gear

flying_pie

I use wireless for gigs but leads in rehearsal because I'm too stingy to keep buying batteries. There's a huge difference in top end between the two, even with the cable length simulation in the wireless unit.

I think my leads are all consistent but this thread has inspired me to actually check that's the case

Nerine

I’ve known cables to affect the sound, usually the top end - especially when not using any buffers or anything. I’ve never known a cable to affect the sound or shift the EQ quite as drastically as is mentioned in OP though. Interesting. 

Danny1969

A typical guitar cable does make a small difference to the tone. It's basically a primitive low pass filter with a tiny amount of resistance and a small amount of capacitance in parallel. A braided screen will add a bit of inductance as well. All of this affects  the higher frequencies more as they pass easier through the stray capacitance from signal wire to shield than low frequencies, so get leaked to ground easier .. just like signal getting leaked to earth in a guitar tone control using an actual capacitor. Then the series inductance in the shield impedes high frequencies more than low frequencies because it's reactance rises with frequency. This effect is very small though, more or less unnoticeable at the most upper frequencies a guitar produces I would have thought.  

BUT when an amp is designed, the effects of the cable are taking into consideration and implemented into the design. The guitar pickup, the cable and the amp are all designed for as a whole. So a typical amp like a Fender or Marshall sounds great with a normal guitar cable. It doesn't need wireless or to be made from Russ Andrews nasal hair for the amp to sound good. 

ICBM

Danny1969 said:

A typical guitar cable does make a small difference to the tone. It's basically a primitive low pass filter with a tiny amount of resistance and a small amount of capacitance in parallel. A braided screen will add a bit of inductance as well. All of this affects  the higher frequencies more as they pass easier through the stray capacitance from signal wire to shield than low frequencies, so get leaked to ground easier .. just like signal getting leaked to earth in a guitar tone control using an actual capacitor. Then the series inductance in the shield impedes high frequencies more than low frequencies because it's reactance rises with frequency. This effect is very small though, more or less unnoticeable at the most upper frequencies a guitar produces I would have thought.

Although it’s true that guitar cables do have both resistance and inductance, the values are far too small to be audible, because the source and load impedances are tens or hundreds of thousands of times higher - a typical cable will have a resistance of around 1 ohm, but the volume pot value on the guitar is usually 250K or 500K, and the input impedance of the amp at least 100K and more often 1M. Likewise the inductance of a guitar pickup is typically a few henries - that’s a huge value, only wound components are anything like that. A cable will be in the microhenries, even if a coiled one.

But the capacitance very much does matter, because a typical cable will be a few hundred pF or maybe just into the low nF range - up to about a tenth of the value of the tone cap in the guitar, and much higher than the input capacitance of the amp.

With speaker cables, it’s the resistance that matters, because both the source and load are a few ohms, or just into the low tens, so a cable with say half an ohm resistance will make an audible difference. Capacitance and inductance are now irrelevant because the inductance of a speaker voice coil is huge, and the capacitance and inductance of an unshielded 2-core cable are microscopic. Even then, once you get below the resistance of a fairly decent gauge cable and it becomes insignificant relative to the rest of the circuit, it makes no further difference.

And with mains cables the only properties that matter are that it’s adequately rated for the maximum current draw of the amp, and doesn’t break .

But if you want you can spend thousands on cables that defy the laws of physics… presumably that sort of magic costs. 

Supportact

On the bright side, you've now got two amps you like rather than one. Sounds like a result to me.