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Re: Not all cables show high order harmonics at JC's

I don't want to quote the whole previous post (most of it is fairly clear anyway and I have no argument with it) but there is one thing to clarify:

Ok.

So unless I missed something, John has never mentioned any cable which he has measured which has shown NO high order harmonics.

In the tests I watched at John's, some cables exhibited very low/no high order harmonics. I think one of the JPS cables, in particular, showed almost nothing on the scope, other than the low order residuals from the oscillator.

I'm just going by what John himself has said:

I found that virtually every wire has its own spectrum.

Even the van den Hul he uses as his reference shows some high order products as evidenced by his Mac The Scope plots. He has also said he's seen increases in the second and third harmonics. That too is evidenced in his Mac The Scope plots. Just compare the second and third harmonics between the Radio Shack and the other two.

Look at the second and third in the AP plots and they're rock solid.

So again, I have never seen any evidence that John has measured a cable which shows NO distortion. Only that some have more or less than others.

The results are also completely repeatable, in that you can swap cables in and out and get the same signature.

But apparently not completely consistent:

...and if I use a cable for testing for too many hours, it seems to 'break-in' and not have the same measured distortion. Then I have to find an untested version of the same cable type to use as a reference (bad cable)

So, over time, the measured distortion changes.

To me the discussion boils down to this:

There is clearly some interaction between the test rig and the cables at JC's. Either (as jneutron suggested months ago) something about each cable is causing the test equipment to generate different harmonics, or the cables themselves are generating them. It's not John's imagination, nor is it sloppy test methodology.

The repeatability eliminates the possibility that it is random or environmental noise, or measurement error.

But it doesn't eliminate the possibility that the distortion is ultimately being produced by his 1700B.

BTW:

You said :We don't need a plausible explanation of John's results.. We do. If we simply pick and choose which data sets we use, and throw out the ones we don't like, then this is religion not science.

I'm not simply picking and choosing and throwing out that which I don't like. I'm applying some basic logic and reason here.

When measured on a system KNOWN to be better than the system John is using and capable of measuring SIGNIFICANTLY BELOW where John's system is measuring, we see no evidence of the distortion John is routinely measuring, even when measuring the most bog standard A/V cable.

So, either the distortion John's measuring is being produced by his 1700B, or the System Two Cascade's generator isn't even AS GOOD as the one in John's 1700B.

Well, we know that the System Two Cascade's generator is better than the one in John's 1700B. An order of magnitude better in terms of THD+N.

So how on earth can you say that data sets are being thrown out simply because we don't like them?

If we can collectively reconcile Bruno and JC's results with a single explanation, then we have moved the SOTA forward.

The state of the art HAS MOVED FORWARD! It's moved forward and given us the Audio Precision System Two Cascade instead of leaving us stuck with 25 year old ST 1700Bs.

There's nothing to reconcile. The System Two Cascade is DEMONSTRABLY BETTER. Period. That being the case, we would have to question Bruno's honesty. And if you wish to call that into question, I'll see if I can find someone else with a System Two Cascade willing to do the same measurements.

Other than Bruno's honesty, the only other thing that's been brought to the table that at least has some rationale behind it is that Bruno didn't measure the same cables as John.

But John has shown no interest whatsoever in resolving that issue.

Talk about religion, John's tenaciously clinging to his measurements and his 25 year old 1700B and lashing out at anyone who dares question them is a page right out of the Catholic Church's playbook, under G for Galileo.

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