Would you change your amp selection knowing...?

@unsound
I found a link to the paper from which the excerpt shown at the link you provided was taken:

http://sound.whsites.net/cable-z.htm

My conclusion reading all of this is that I wouldn’t worry about his allegation that the resistor value chosen by Goertz is not ideal. As he even said, based on his simulations: (Comments shown in brackets are mine):

Even 100nF in series with 10 ohms restores the amplifier phase margin to normal.... 4.7 ohms is preferable, but the phase margin is barely affected. The speaker end response has a small ’lump’ with 10 ohms [between about 5 and 10 MHz!], and phase goes ’wobbly’ at above 20MHz. This is probably not a concern, and you will almost certainly get away with it.

I don’t, however, see any reason to doubt his statement that:

It is very evident that this particular cable [Goertz MI 1] should never be used without a Zobel at the speaker end....

Best regards,
-- Al

Would speaker cables that use separate jackets for the + and - speaker have zero (no) capacitance?

Unsound, thank you kindly for the gracious response.  Cycles2, separating the two conductors as you describe will result in capacitance being very low, although not zero.  However, it will cause inductance to be considerably higher than if the conductors were in close proximity.  And in a speaker cable inductance is much more likely to be a significant factor than capacitance, aside from the situation that has been discussed in which cable capacitance is ultra-high and the amplifier is sensitive to that.

High inductance is particularly likely to have significant sonic consequences if speaker impedance at high frequencies is low (such as in the case of most electrostatic speakers) and cable length is long.  That is because the impedance presented by an inductance is directly proportional to frequency, and cable inductance is directly proportional to length.

Regards,
-- Al
 

I saw this thread and recalled a review of the Schiit Vidar amp when it first came out.  I think it was the computer audiophile site, and when the reviewer tried his 9 gauge cables, the amp started having issues.  

The reviewer sent the amp back to Schiit, they did some investigating and decided to make a change to the amp as a result.  Personally I don't see the need to ever employ 9 gauge speaker cables in any of my systems, but there you go.

@ghosthouse - I don’t profess to be an expert or anywhere near that, since I have only been "tinkering" with the effects of cable design and geometries for about the past 4 years,

WRT...

I wonder if their, "...barring a really odd design, which may introduce various undesirable effects...." is tacit acknowledgement of the oscillation risk you raise

In short - yes, I believe so to.

But I would interpret "odd design" to be a reference to the diealectric attributes of the insulation used, and cable geometry, because they too are a factor in the capacitance of the cable.


But there are a couple of points in the text you posted that I believe should be expanded upon, e.g. ...

The first point...

speaker cables are, for all practical purposes, immune from interference from EMI or RFI,

When EMI/RFI is introduced into the conversation it is generally with respect to external EMI/RFI influences.

However, I believe the Proximity Effect, which is EMI/RFI between the conductors within a cable has a far greater impact than people are led to believe.

From that perspective, speaker cables are probably affected the most due to the higher voltages and current they are subject too..

An "experiment" that I tried - which I believe demostrates the impact of the Proximity Effect in speaker cables - like the D352...

I listened to the D352 as is - then I seperated the two conductors and allowed about 2" of space between the conductors.

The impact of simply seperating the two conductors was a significant improvement in sound quality across the board,...

- better bass control and depth
- improved image
- improved clarity
- improved dynamics

The second point...

The answer to keeping conductivity high is simple: the larger the wire, the lower the resistance, and the higher the conductivity.

I feel this is also not the entire story - so let’s disect it a little further.

According to the International Annealed Copper Standard - IACS

1. Silver (Pure) 105%
2. Copper 100%
3. Gold (Pure) 70%
4. Aluminum 61%
5. Brass 28%
6. Zinc 27%
7. Nickel 22%

And - If you delve a little deeper, you will find it is the valance electrons in an atom that conduct "electricity"
https://www.reddit.com/r/askscience/comments/j298b/what_makes_copper_silver_and_gold_so_much_more/?s...

QUOTE from the link above:

As atoms get larger however, more and more electrons are between the nucleus and valence shell, shielding the outermost electrons from the nucleus’ influence. This is why silver is a better conductor than copper, it is a larger atom with a more strongly shielded nucleus.

But since the valence electrons in silver are less influenced by the nucleous it takes far less force to have them switch between atoms.

The net resuilt of all this science
- not only is silver a better conductor - i.e. from a resistance perspective)
- it is a FASTER conductor.due to the shielded valence electrons

So - it is not JUST the size of the cable, but the material the conductor is made from.

FYI: in my tinkering with cables, I have tried cables of of various sizes and cables that are just copper and cables that are silver coated copper.

Personally I liked the speed and details of the siver coated cables.

The larger gauge did seem to convey deeper more well controlled bass frequencies than lighter gauge i.e. with cables that used a simple cable geometry.

HOWEVER - all that changed once I made cables with a HELIX cable geometry.

The HELIX Cable provided better performance across the board, especially improved bass depth and control,
However, it did so using lighter gauge conductors

In my case...
- I was using a 10 gauge Van den Hul D352 speaker cable (silver plated)
- I now use a cable with
--- a 16 gauge Silver plated signal conductor and
--- a 13 guage tinned neutral conductor

SO...
- selecting a heavier gauge cable is a simplistic approach.
- I believe selecting cable with a well designed geometry is a far better solution.

One such cable is the QED Silver Spiral.
- please note that I have not personally tried this cable,
- BUT the geometry of this cable is similar to my own HELIX design and should make this cable a very good performer.
- I have also heard from others that seem to like this cable very much

It is my belief that most large cable manufacturers are aware of the cable capacitance issue and they may not publish the capacitance values because...
- the capacitance of their cables do NOT pose a problem.
- also, they fear it may just "muddy the waters" for many consumers.

Hats off to companies like CARDAS and Van den Hul, for ensuring capacitance values for their cables are published.

Yes - it would ne nice if ALL cable companies posted full cable attributes

But - l beileve it is up to the manufacturer of the amplifiers likely to be affected by the wrong cable choice, to make their consumers aware of this issue, like NAIM does

Apologies for the long post - Steve

@williewonka

Thanks for taking time to reply. No need to apologize for the length. Appreciate your efforts to be thorough. Still digesting, though on the initial read-through you've provided worthwhile elaboration on BJC's comments.  Performance not simply a function of conductivity as influenced by gauge, but metallurgy, and geometry too.  I think your idea of separating to reduce locally generated "intra cable" interference is practiced by mftrs. producing "flat" cables like Wireworld and Mapleshade (others too, no doubt).  Thanks again.  

I tend to agree with anhwy61, shadome, almarg and others that feel there is no reason for high capacitance in a cable. To Al's statement "A cable having extreme and/or unusual parameters would be a non-starter for me" - I say "DITTO". The amps mentioned in the OP are neither cheep nor poorly designed. Over the years, I've come to the conclusion that the three main attributes of good cables is: high conductivity, low capacitance and low inductance. Beyond that, IMO, there are a lot of very expensive gimmicks out there that do nothing more than alter or degrade the the original signal. Signal loss and degradation is also the reason that high capacitance cables do not work for high speed data processing....Jim

In my last sentence, I meant to say - high speed data transfer.
Regards, Jim

 Thanks for starting this thread-I had no idea that this was a potential issue with my system!   I completely agree with @elizabeth  that it is both the amp and cable manufactures’ responsibility to warn the public if there is a potential issue with their product.

 Unfortunately, much of the electrical discussion I find to be extremely dense.  It would be a great service to the audio community if someone would provide a layman’s rule of thumb for determining whether their system may be  subject to harmful isolation to to  a poor match between amp and cables. 

@cheeg While I’m not an expert by any means, I have been an audio enthusiast for more than 35 years and have had the opportunity of owning or extensively auditioning some very nice equipment - speakers, amps, cables and accessories - some combinations working very well together and some not. Regarding cables, IMO that there is little to no reason to use high capacitance cables for any system, regardless of speakers and whether powering with a ss amp (particularly a high currant ss amp) or tubes. I have one set of low capacitance, highly conductive (individual strands of polyethylene insulated Oxy free pure copper)) cables, that I now use always, regardless of what I trade in and out of my system, knowing that they will allow me to hear subtle differences in everything else without adding a character or coloration of their own. I have no worries of them raising havoc with any of my high currant amps and they work equally well with tubes. My RCA interconnect cables are short run, low C pure silver and I have no desire to change them either.....just some thoughts...Jim

@jhills - WRT...

I tend to agree with anhwy61, shadome, almarg and others that feel there is no reason for high capacitance in a cable.

The only "reason" as such, pertains to adopting a particular cable geometry in order best to combat cable related noise issues.

The cable geometry used in one CARDAS cable having high capacitance is a very low noise design - effective at attaining the "black background "

The "side effect" of that particular geometry is high capacitance
- which is not an issue with tube amps
- and is only an issue with SOME high current solid state amp designs

Can you acjieve the same black bakground with a different geometry?
- I believe so - but they may be more complex to manufacture

There’s are many ways to "skin a cat" - in the end - it all boils down to cost.

Hope that helps - Steve