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Old 26th Feb 2021, 1:35 pm   #2081
mole42uk
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Default Re: The Audiophoolery Thread.

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Originally Posted by Craig Sawyers View Post
I see your cheapo Tellurium and raise you a Nordost Valhalla https://www.futureshop.co.uk/nordost...pe-b-usb-cable

Craig
Please don't!

I followed the link, read the first paragraph and had to reach for my pills.....
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Old 26th Feb 2021, 2:02 pm   #2082
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Default Re: The Audiophoolery Thread.

It does seem particularly strange to me that this audio woo is applied to digital interconnects. If you're buying a cable to connect a high end record deck to a preamp, it's not impossible that an expensive cable will sound better, and indeed it's very difficult to prove conclusively that it won't. All you can do is run some double blind subjective comparisons.

With digital interconnects, you can look at the zeros and ones at each end, and clearly see that the information hasn't changed. I think this was first done to debunk those marker pens that were sold to 'improve' CDs in the 80s, but all digital technology can be examined in the same way. It's not a subjective judgement, it's just physical reality.
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Old 26th Feb 2021, 2:12 pm   #2083
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Default Re: The Audiophoolery Thread.

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Originally Posted by chriswood1900 View Post
Surely this is just an excellent way of redistributing wealth!
From the gullible to the exploitative? Compared to other well known wealth redistribution methods, at least this one avoids the need for dressing up in green tights and silly hats, and learning to shoot a bow. I'm just not sure that it moves the brass in the right direction.

David
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Old 26th Feb 2021, 2:15 pm   #2084
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Default Re: The Audiophoolery Thread.

We could explain digital interconnects in audiophile language:

"Your nice pure sound has already been so much corrupted in converting it to and from a digital format away from its natural analogue nature that even the best cable in the world is wasted!"

There, that ought to be understandable by them.

David
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Old 26th Feb 2021, 2:41 pm   #2085
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Default Re: The Audiophoolery Thread.

There is one serious point to do with changing one cable for another of whatever type - the connections are new.

As someone who has fought with strange signals as a result of tarnished or otherwise flaky old BNC leads and chassis connectors, I suspect that *if* there is a perceived difference between an older and a newer audio cable, it could just be down to the connection itself.

What was the old adage? A connector is a source of trouble between two pieces of functioning equipment.

Craig
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Old 26th Feb 2021, 3:18 pm   #2086
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Default Re: The Audiophoolery Thread.

Quote:
Originally Posted by paulsherwin View Post
It does seem particularly strange to me that this audio woo is applied to digital interconnects. If you're buying a cable to connect a high end record deck to a preamp, it's not impossible that an expensive cable will sound better, and indeed it's very difficult to prove conclusively that it won't. All you can do is run some double blind subjective comparisons.
If you've ever looked at the very best MC carts, playing a flat 1K test record, on the outer groove at 45rpm, you'll notice that the 2nd harmonic is still around -50dB. In the case of cheap carts, and ones designed for DJs, the 2nd can be above -30... The question in my mind would be, even if such a cable gave those pesky electrons a therapeutic massage on their way along the cable, how would the improvement manifest itself musically?

I wonder how many here have ever brought up the concept of A/B/X testing amongst those who work in the hifi industry? It's basically a way to get blacklisted... And if you managed to arrange such a test, there would *always* be a pseudo-scientific objection to the methodology to undermine any findings.

I am reminded of Carl Sagan and his Dragon in the Garage: http://people.whitman.edu/~herbrawt/.../110/Sagan.pdf

Quote:
With digital interconnects, you can look at the zeros and ones at each end, and clearly see that the information hasn't changed. I think this was first done to debunk those marker pens that were sold to 'improve' CDs in the 80s, but all digital technology can be examined in the same way. It's not a subjective judgement, it's just physical reality.

There is a really frightening review on What Hifi? where they mark a USB cable down for having 'flaccid bass'.
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Old 26th Feb 2021, 4:07 pm   #2087
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Default Re: The Audiophoolery Thread.

You can get some very nice looking USB leads with anodised aluminium (now there is a good word to type) covers and lovely looking braided leads for less than a tenner. That ultra expensive one used heatshrink sleeving, what is the world coming to?

I had a chap come into my woffice (workshop office, the BBC coined that one and I am sticking to it to stop having to go to a real office) this morning with a 'speaker lead for his motorcycle (yes 'speakers on a bike) asking how to terminate some silly sized cable into a crimp connector to make it sound better. He left happy and educated about such foolery.
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Old 26th Feb 2021, 4:08 pm   #2088
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Default Re: The Audiophoolery Thread.

I'm probably going to regret this but I'm going to relate two recent cable-related occurences. As some of you know, I am a hi-fi reviewer for a couple of UK hi-fi magazines, but am also an electronic engineer with a great deal of cynicism when it comes to cables and the general ridiculousness that surrounds them. So, onto recent happenings:

(1) I recently received an item for review which came with a £700 interconnect as part of the package so, naturally, I used this for the review. Now the review item in question was superb – really good, however I noticed when I came to disconnect it at the end of the review that the interconnect had arrows on it that I hadn’t spotted and it turned out that I had been listening to it for weeks connected…..wait for it…… the WRONG WAY ROUND!

Now, as a qualified engineer who has also been faffing with hi-fi since I was about 14, I am well aware that the concept of a difference in sound due to cable directionality is utter poppycock but, just for a laugh and for completeness sake, I turned it round the ‘right’ way and listened to my last couple of test tracks again. Result? Absolutely no difference. Obviously.

This then got me thinking and wondering just how much of the superb performance of the review item was down to this interconnect and whether I should mention in the review that you weren’t going to hear it at its best without it. Hence me substituting in the regular interconnects that I use, which are around £120 per set, and the astonishing revelation that it sounded exactly the same. My eyes then alighted upon a 3m long cheapo interconnect (about £22 IIRC) that I happened to be lying around so I stuck that in for a laugh and, again, no change.

The £700 interconnects went back with the review item and so I’m sticking with the £120 ones. Why not the £30 ones, I hear you ask? Well, not only are the £120 ones prettier, but they have also proven to be well up to the repeated plugging/unplugging and general abuse that I subject them to in the course of reviewing – I’m less convinced that the £30 ones will last as long. Frankly this is far more important to me than whether they make my blacks inkier and my midrange more mellifluous. Which it turns out that, compared to the £30 ones, they don’t anyway, so I can stop worrying about it.

Not that I was worrying about it. They’re only wires, after all. But then came happening number two:

(2) Due to the utterly chaotic state it has been in recently, I've been spending a few weekends tidying, organising and re-arranging my listening room. Due to the big re-arrange, I took the opportunity to change from a pair of good quality Heco bi-wire speaker cables that have performed faultelssly for me, for over 20 years but on which the insulation is starting to become brittle and which were just a smidge too short for tidy routing in the new equipment layout.

I swapped these for some super-duper cables that I used to use in the lounge before we went over to active speakers. Result? hard, shouty midrange, complete collapse in soundstage and just completely ruined the balance of my setup. I summoned Mrs. Beobloke for a quick test as she plays the piano and flute and has an excellent ear for music and sound quality. She is also a lady of instant decision and few words, and managed about twenty seconds of the test track I played her on the fancy former lounge cables (note - I didn't tell her which cables were which) before grimacing, getting up, walking out and telling me in no uncertain terms - "Whichever ones those are; get rid of them".

Naturally, being a dutiful husband, I added some heatshrink over the cracking insulation of the old Heco cables and put them back. All is now well once more.

I would finish by adding that I have also heard differences between conventional coaxial digital cables which both confused and annoyed the hell out of me - after all, it's only ones and noughts isn't it?
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Old 26th Feb 2021, 4:34 pm   #2089
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Default Re: The Audiophoolery Thread.

Straight analogue audio over domestic distances isn't difficult to connect. If you start getting audible differences with non-extreme cables, then something somewhere is wrong and I'd be digging hard to find just what and to understand it. Only in this way can you sort out a problem and then know that it ought to stay sorted.

Things are different with digital connections. With serial data sent at a reasonable bit-rate to fit it all in along with checksums and framing, the bandwidth goes up dramatically and the very-short-compared-to-a-wavelength thing goes out the window. You need clean edges and a good opening on an eye diagram to get low error rates. This means lines must be terminated properly to avoid triple transit echoes and higher order bounces. You really need to look at the waveform delivered at the receiving end and look for rings and ISI.

Seemingly minor changes can move the timing of echoes and position spikes right at the decision time of your eye diagram and the error rate can jump dramatically.

Digital things with error correction can appear perfect right up to the point and then there is nothing graceful about their degradation.

Peter Scott on this forum and myself were involved for a while in measuring the error rates of data links for telecomms systems and their vulnerability to jitter and other impairments. I got involved in the vulnerability of digital radio systems to signal to noise and interference. These things are all quite understandable, but when something seems to go wrong, it needs investigating so that you can fix it with confidence that it wasn't just luck.

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Old 26th Feb 2021, 4:39 pm   #2090
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Default Re: The Audiophoolery Thread.

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Originally Posted by Beobloke View Post

I would finish by adding that I have also heard differences between conventional coaxial digital cables which both confused and annoyed the hell out of me - after all, it's only ones and noughts isn't it?
Once it is proven that the data is identical both ends, it has to be subjective, impossible for it to be cable differences unless one is intermittent.
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Old 26th Feb 2021, 4:41 pm   #2091
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Default Re: The Audiophoolery Thread.

I usually just use whatever is lying around to perform a digital connection to the DAC bit of the CD player.
I find its really useful to skip/ignore the cable reviews in magazines, and when the record shop in Carlisle re opens I'll be in there browsing and spending money on the stuff that makes the stereo sound so good to me. .......... Music.

However if I was really exercised on choosing a digital interconnect I'd try and find a pro audio engineer and ask what they used.
And Craigs observation on the tarnishing of contacts is where many of us more cynical audio enthusiasts reckon people hear any improvement, the mere action of wiping a socket and plug contact together can improve electrical contact.
Some of us have said so in certain forums (fora?) and been told we are wrong..... I have done my experiments on speaker wire (I hate the word "cable" that's something you hang a ships anchor off in my world) and connecting leads in the past and bizarrely I now stick to my nice long length of generic 79 strand copper wire and I had equally good results using ordinary 7 amp double insulated lighting flex, this compared to a couple of 2m lengths of some silver plated Chord company wire, their less expensive one, and I am never sure there is a difference so on that bombshell...................

Andy.
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Old 26th Feb 2021, 5:13 pm   #2092
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Default Re: The Audiophoolery Thread.

David is on the money here as normal. You only 'hear' a cable if it's the wrong type for the job or there's a contact fault. Try using a cable for guitar pickups that doesn't have low C (it might suit the sound you're after...). And SPDIF digital cables need to have low C.

Biker makes a good point re: tarnished contacts. You get huge THD increases for bad contacts. You can see what bad contacts do on an FFT easily, and it can be apparent even with low Z / line level connections, making one realise how important decent connectvity has to be for phono and instrument pickups. A connection can be 'just' making contact, where you see a lot of ugly distortion.

In summary, if you use a cable that's designed for the job, and your connectors are tight and clean, then spending more than you might on a decent Belden / Klotz whatever is a phool's pursuit.
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Old 26th Feb 2021, 5:21 pm   #2093
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Default Re: The Audiophoolery Thread.

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I see that the Nordost Valhalla 6m USB cable with DeoxIT Gold G-Series contact enhancer and burnt in for 96 hours is a snip at £8,783.
But that length is greater than the maximum single cable length of 5m for USB 2 according to the USB2 spec. Unless of course the contact enhancer and burn in compensate for that.

Keith
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Old 26th Feb 2021, 5:57 pm   #2094
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Default Re: The Audiophoolery Thread.

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Originally Posted by Radio Wrangler View Post
Straight analogue audio over domestic distances isn't difficult to connect. If you start getting audible differences with non-extreme cables, then something somewhere is wrong and I'd be digging hard to find just what and to understand it. Only in this way can you sort out a problem and then know that it ought to stay sorted.

Things are different with digital connections. With serial data sent at a reasonable bit-rate to fit it all in along with checksums and framing, the bandwidth goes up dramatically and the very-short-compared-to-a-wavelength thing goes out the window. You need clean edges and a good opening on an eye diagram to get low error rates. This means lines must be terminated properly to avoid triple transit echoes and higher order bounces. You really need to look at the waveform delivered at the receiving end and look for rings and ISI.

Seemingly minor changes can move the timing of echoes and position spikes right at the decision time of your eye diagram and the error rate can jump dramatically.

Digital things with error correction can appear perfect right up to the point and then there is nothing graceful about their degradation.

David
I was involved in an increasingly acrimonious conversation with another guy on an unmentionable forum regarding just this issue. And his general attitude and final comment "What are you on?" led to me blacklisting him.

Leaving that irritation aside, there seems to be a blind spot in many audio designers when it comes to a digital link. Usually pulse transformers are used at either end to give galvanic isolation. Nothing wrong with that in principle. The problem comes from the detail.

Taking the 75-ohm SPDIF link for the moment. Pulse transformers for audio application actually like working at 130-160 ohms typical, determined by the leakage inductance and interwinding capacitance. That can be fixed at the send end simply by using a matching pad - which no commercial design that I have come across does.

At the receive end, similar precautions need to be taken. However, whatever you try to do with the pulse transformer, the secondary ends up going in a logic gate - usually a Schmitt trigger - which has a non-linear input impedance. You really need to use a high speed analogue buffer between the pulse transformer and the logic. Again - no commercial design does this that I have seen.

You can easily see the effects by examining send and receive impedances using TDR, or breaking into the digital stream using a three way splitter and looking in the time domain on an oscilloscope.

So it is little wonder that strange digital cables make a perceptible difference.

However - and here is the cheap way to do this - use a long 75 ohm connection. If it is around the 3-5 metre length, pulse reflections from either end, come back well away from the edges and die away before the next transition. 5 metre long 75 ohm premade video cables, BNC terminated, are available from Canford for less than £15

Oh and of course use 75 ohm BNC's and not RCA, which are nothing like 75 ohms.

Craig

Last edited by Craig Sawyers; 26th Feb 2021 at 6:11 pm.
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Old 26th Feb 2021, 6:15 pm   #2095
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Default Re: The Audiophoolery Thread.

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Originally Posted by knobtwiddler View Post
David is on the money here as normal. You only 'hear' a cable if it's the wrong type for the job or there's a contact fault. Try using a cable for guitar pickups that doesn't have low C (it might suit the sound you're after...). And SPDIF digital cables need to have low C.

Biker makes a good point re: tarnished contacts. You get huge THD increases for bad contacts. You can see what bad contacts do on an FFT easily, and it can be apparent even with low Z / line level connections, making one realise how important decent connectvity has to be for phono and instrument pickups. A connection can be 'just' making contact, where you see a lot of ugly distortion.

In summary, if you use a cable that's designed for the job, and your connectors are tight and clean, then spending more than you might on a decent Belden / Klotz whatever is a phool's pursuit.
A bad, corroded connection can also act like a cat's whisker, giving a mild diode effect.
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Old 27th Feb 2021, 3:25 pm   #2096
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Default Re: The Audiophoolery Thread.

this sort of thing has been going on for ears, yes I know I am stating the obvious, but people always think that paying more gets you better stuff, and not just for audio either i.e: when I worked at the CO Op in the 70s we sold Bush and Murphy tvs with the Bush or Murphy badge, they looked exactly the same just the badge was different, no problem. But we also sold Defiant made by Bush/Murphy but were £50 cheaper. They looked exactly the same as their Bush/Murphy brothers but what a difference in price, and people would still buy the more expensive sets because they were better. I even said to one customer that if the were worried about someone seeing the Defiant badge just remove it and no one would know the difference but they still bought the Bush version. £50 in the 70s was not an inconsiderable amount of money
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Old 27th Feb 2021, 7:45 pm   #2097
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Default Re: The Audiophoolery Thread.

I was asked a week or so ago to have a look at a "expensive Amplifier" that had a crackle. I reluctantly agreed and this huge wooden box was delivered to me containing a heavy chassis with lots of chrome cans. The cans appeared to be glued in place!
To access the underside I had to remove the glued on plastic bottom. What I found you can see in the pictures. The output transistors are held in with a sort of cement , this also provides isolation from the chassis!
The two small circuit boards are not even fitted straight and one is further away from the chassis than the other.
The cans have capacitors and mains transformers in them also held in place with cement.
The bridge rectifiers are glued in place the whole thing to me looks horrid.
The biggest laugh is the two large black boxes on the top, all they contain is a LED and a phono socket!
The big beefy screened mains lead goes into a chock block connector and the screen is not connected either end.
The fault was an intermittent crackle on one channel I found it was due to one of the connections to one of the chassis mounted capacitors to be very badly soldered and loose.
I soldered the wire back on glued the bottom back on and put it back in it's foam padded wood box.
I just told the owner it was OK now I didn't say what I thought of it!
What do you think? am I right ? surely this is just a dressed up pile of crap?
maybe the empty plastic boxes once contained snake oil and it has leaked or evaporated!?
The last pic shows the capacitor that had the dry joint or loose wire to be more accurate this one is held in place with silicone sealant so either they ran out of cement or the cap has been changed.
Sorry that the pics are upside down etc I cannot find a way to rotate them . Maybe a mod would be kind enough to oblige?

Rich
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Last edited by slidertogrid; 27th Feb 2021 at 7:51 pm. Reason: Added a bit
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Old 27th Feb 2021, 7:58 pm   #2098
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Default Re: The Audiophoolery Thread.

Astonishing. It appears to have been made by someone who was actually mad. Though they may have actually been very sane, very perceptive and thus very rich.... I'm blinking with amazement!
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Old 27th Feb 2021, 8:14 pm   #2099
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Default Re: The Audiophoolery Thread.

Half baked (expensive) specialist one-off builds for the retail market are an up and coming problem, I fear. I saw something equally nasty for sale recently, it wasn't audio but a ham fisted bespoke appliance even worse than that pictured. £150 was asked for it; it needed putting into WEEE really.
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Old 27th Feb 2021, 8:46 pm   #2100
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Default Re: The Audiophoolery Thread.

Ye gods and little fishes!

What you have there is the work of an audio mage of at least level seven or eight!

Not only was the type and value of every component selected only by listening, all components have been positioned by ear and only then soldered and cemented in place.

Everything is glued together because an audibly superior glue is far better than screws because it is usual to use all right-hand threads throughout and this gives an amplifier a degree of handedness. Opinions vary about whether each amplifier would be better with an even balance between left and right handed threads, or whether it would be best to go to monoblocks with all left hand in one amp, all right hand in the other. Cement is a very clever way of circumventing this uncertainty in a stereo amplifier. Opposite-handed arrangements are needed for the Southern hemisphere of course.

Notice that only the very thinnest and carefully minimised wire is used for absolute purity.

Oh, is it CE marked?

David
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