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"Low Capacitance" Cables?

dlaloum

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Hey folks, thought I'd drop in a cable question here:

At what point do mismatched cable lengths matter to the stereo signal, and what could be affected?

I presume that, for instance, connecting unbalanced RCA cables between a pre-amp to an amp, using a 3 foot cable for the Right channel and 6 foot for the Left channel would be unlikely to produce any audible issues. But then, at what point WOULD there be issues? How much longer would the Right channel cable have to be before problems arise? I presume one problem could be you hit high frequency roll off by sheer length. But, any other issues? Like a mismatch of the timing of the signal between left and right signals to the amp?

Same question goes to mismatched length of speaker cables.

Thanks.
the mismatch will affect capacitance and resistance (also additional potential EM interference)...

For situations where these parameters have a negligible impact on actual performance, eg: typical line level connections - there would be little noticeable impact (it might be measurable, but very very low level) - and most likely swamped by other aspects of performance pertinent to the components at either end.

If we are talking about phono interconnect, ie: the cable that goes from cartridge to phono stage, and the cartridge is a high inductance cartridge (MM / MI or similar) - then the difference could be huge, as you would likely be doubling the capacitance of the cable, and that will directly impact the frequency response from around 3kHz up.... difference would be highly audible, no "golden ears" needed.

In this latter situation the cable capacitance, the resistive load and the cartridge inductance form an Equalisation network / filter - if you change the parameters it has quite a dramatic impact.

It's not good practice to use missmatched cables... but in many cases it can be lived with.
 

Chrispy

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@MattHooper when I saw this thread I thought it was going to be very old....for such a vinyl guy how could you not look into this aspect earlier? I remember when I got my first tt that this was a factor (and that was pre-internet of course :) ). Just curious....
 

Angsty

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Hey folks, thought I'd drop in a cable question here:

At what point do mismatched cable lengths matter to the stereo signal, and what could be affected?

I presume that, for instance, connecting unbalanced RCA cables between a pre-amp to an amp, using a 3 foot cable for the Right channel and 6 foot for the Left channel would be unlikely to produce any audible issues. But then, at what point WOULD there be issues? How much longer would the Right channel cable have to be before problems arise? I presume one problem could be you hit high frequency roll off by sheer length. But, any other issues? Like a mismatch of the timing of the signal between left and right signals to the amp?

Same question goes to mismatched length of speaker cables.

Thanks.
Probably no difference with line level signals and maybe some with MM phono output given capacitance mismatch. At the speed of light, any potential audio cable length difference is imperceptible for timing.
 
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MattHooper

MattHooper

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the mismatch will affect capacitance and resistance (also additional potential EM interference)...

For situations where these parameters have a negligible impact on actual performance, eg: typical line level connections - there would be little noticeable impact (it might be measurable, but very very low level) - and most likely swamped by other aspects of performance pertinent to the components at either end.

If we are talking about phono interconnect, ie: the cable that goes from cartridge to phono stage, and the cartridge is a high inductance cartridge (MM / MI or similar) - then the difference could be huge, as you would likely be doubling the capacitance of the cable, and that will directly impact the frequency response from around 3kHz up.... difference would be highly audible, no "golden ears" needed.

In this latter situation the cable capacitance, the resistive load and the cartridge inductance form an Equalisation network / filter - if you change the parameters it has quite a dramatic impact.

It's not good practice to use missmatched cables... but in many cases it can be lived with.

Thanks very much.

I've slightly re-arranged my amplification so one monoblock amp is a bit further from the preamp than the other. I am going to buy some new unbalanced RCA interconnects and wasn't positive whether it mattered if I used slightly different lengths or whether I needed to match the lengths. Thought I'd ask to make sure.

@MattHooper when I saw this thread I thought it was going to be very old....for such a vinyl guy how could you not look into this aspect earlier? I remember when I got my first tt that this was a factor (and that was pre-internet of course :) ). Just curious....

The first thing is I'm an electronics dunce. I know electricity lives in the walls and god help us if it ever escapes...but beyond that I need help. :)
Also, I was only asking in regard to RCA connections between preamp and amp (and speaker cables). I never thought to ask about different lengths for the cables from my cartridge to phono stage because those are hard wired in to the arm (it seems) and it never would have occurred to me to mess with them.
And I'm no vinyl expert in any case.

Probably no difference with line level signals and maybe some with MM phono output given capacitance mismatch. At the speed of light, any potential audio cable length difference is imperceptible for timing.

Thanks Angsty. Though, wondering if I'll encounter a mismatch problem should a worm-hole descend on my house....
 

Chrispy

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The first thing is I'm an electronics dunce. I know electricity lives in the walls and god help us if it ever escapes...but beyond that I need help. :)
Also, I was only asking in regard to RCA connections between preamp and amp (and speaker cables). I never thought to ask about different lengths for the cables from my cartridge to phono stage because those are hard wired in to the arm (it seems) and it never would have occurred to me to mess with them.
And I'm no vinyl expert in any case.
No worries, most of the technical stuff isn't native to me either. I don't screw with my home's wiring if that's a clue. My tt came with a particularly spec'd, and not easily detached pair of rca cables, but had spec in the manual. Just more curious how these details didn't come into play as much as you find differences in amps for example....
 
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MattHooper

MattHooper

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No worries, most of the technical stuff isn't native to me either. I don't screw with my home's wiring if that's a clue. My tt came with a particularly spec'd, and not easily detached pair of rca cables, but had spec in the manual. Just more curious how these details didn't come into play as much as you find differences in amps for example....

I bought my current turntable already set up - e.g. arm and cartridge. I've had to change the cartridge once, but have never messed with the arm.
I never bought in to the high end cable thing but of course I want to make sure I'm not making any basic mistakes in choosing cables, if an issue like I've raised here comes up.

I don't go looking for sonic differences between solid state amps. Only in the case of tube amps where differences are at least plausible.
 

Chrispy

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I bought my current turntable already set up - e.g. arm and cartridge. I've had to change the cartridge once, but have never messed with the arm.
I never bought in to the high end cable thing but of course I want to make sure I'm not making any basic mistakes in choosing cables, if an issue like I've raised here comes up.

I don't go looking for sonic differences between solid state amps. Only in the case of tube amps where differences are at least plausible.
In that case it may be more about possible matches intended by whoever setup arm/cartridge? Dunno, but suppose it could still have a particular better match in mind....

I can't imagine bothering with tube amps at all myself, just because you're working with odd variables.
 
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MattHooper

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In that case it may be more about possible matches intended by whoever setup arm/cartridge? Dunno, but suppose it could still have a particular better match in mind....

I can't imagine bothering with tube amps at all myself, just because you're working with odd variables.

That's part of the fun; the surprises :)
 

dlaloum

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The first thing is I'm an electronics dunce. I know electricity lives in the walls and god help us if it ever escapes...but beyond that I need help. :)
No No, you completely misunderstand it... the components and wires contain and constrain "magic Smoke" - if the smoke is released they cease functioning...

All this "electronics" stuff is a conspiracy theory, fake news.... ;)

(much like the "birds" conspiracy theory, I am sure this could be further developed!)
 

egellings

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Hey folks, thought I'd drop in a cable question here:

At what point do mismatched cable lengths matter to the stereo signal, and what could be affected?

I presume that, for instance, connecting unbalanced RCA cables between a pre-amp to an amp, using a 3 foot cable for the Right channel and 6 foot for the Left channel would be unlikely to produce any audible issues. But then, at what point WOULD there be issues? How much longer would the Right channel cable have to be before problems arise? I presume one problem could be you hit high frequency roll off by sheer length. But, any other issues? Like a mismatch of the timing of the signal between left and right signals to the amp?

Same question goes to mismatched length of speaker cables.

Thanks.
Depends on the output impedance (Zo) of the amplifier driving the cable and largely, the capacitance of the cable if Zo is high.
 

Speedskater

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If the component has a modern design interconnect output stage (output impedance of less than a few hundred Ohms) and the cable has a reasonable shielded design. Then total cable capacitance won't be a factor until the cable is ridiculously long.
 

dlaloum

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If the component has a modern design interconnect output stage (output impedance of less than a few hundred Ohms) and the cable has a reasonable shielded design. Then total cable capacitance won't be a factor until the cable is ridiculously long.
ie: Line level signals/interconnects - not a problem

issues arise with special cases such as Turntable interconnects to phono stage.
 
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