The Audiophoolery Thread.

Is that a standard silver shorting block, or a high end honey coated, cryogenic treated, non inductive, directional silver shorting block: enquiring minds need to know.

[Radio Wrangler]

Any. Just so long as it's reassuringly overpriced.

David

[bigfathairyvika]

Could suggest a useful addition to their directional cables, a series diode to stop signals attempting to go the wrong way.

[fetteler]

Originally Posted by Radio Wrangler

Any. Just so long as it's reassuringly overpriced.

David

Wasn't there some horrid lager brewer that used to try to hoodwink their gullible victims with a similar sales pitch?

Steve.

[Craig Sawyers]

Back to total insanity. How about an ethernet cable costing £3,430.00 for 1metre?

https://www.futureshop.co.uk/nordost-valhalla-2-ethernet-cable

Or £25,530.00 for 0.6metres of RCA terminated cables

https://www.futureshop.co.uk/nordost-odin-2-audio-interconnect-rca-pair

Share and enjoy

Craig

[Radio Wrangler]

If you've just spent upwards of £100k on some boxes, spending a few quid on some bits of wire to go between them can easily be made to look mismatched

Anyone paying high-end prices is already advertising their gullibility, and there is a whole cottage industry geared up to fulfil their needs.

There's a lot of reassurance in tham thar cable and fuse prices.

Does the ethernet price mean that the cable comes pre-filled with harmonious data?

David

[Craig Sawyers]

They suggest that they can burn in cables using the Nordost Vidar burn in system.

There are some half way detailed photos on the web of this. It basically generates pseudo random noise using a long repeat length tapped shift register. Then there are various drive circuits for different cables and timers. Cable companies charge for such a burn in of course.

I designed one using tapped shift registers back in the early 80's in my first job, with a repeat length measured in decades. For an industrial application. Fed into a D-A to give real noise-like signals.

And more recently a noise generator based on avalanche in a pn junction, converted to pink noise and then a power amp to test loudspeakers to near destruction. By measuring the current you can work out the coil temperature.

Craig

[Craig Sawyers]

And because Wikipedia is your friend - tapped shift register noise generation

https://en.wikipedia.org/wiki/Linear-feedback_shift_register

Craig

[mark_in_manc]

Originally Posted by Craig Sawyers

Back to total insanity. How about an ethernet cable costing £3,430.00 for 1metre?

https://www.futureshop.co.uk/nordost-valhalla-2-ethernet-cable

Or £25,530.00 for 0.6metres of RCA terminated cables

https://www.futureshop.co.uk/nordost-odin-2-audio-interconnect-rca-pair

Share and enjoy

Craig

I don't have any ethernet cable at home, but I do have quite a lot of random x-to-y cables including phono cables. Since I believe they work as well as the ones on display here, I'm going to have a little look around later this morning, count up how many I can find, multiply the number by £25k and rejoice at all the money I have saved. I suspect it will be more than my total net worth (including the house)

(Previously I rejoiced at selling some B&K jack plugs at about £10 a pop as part of my charity sell-up, but I see now I was woefully unambitious!)

[emeritus]

As far as I know, the only type of electric cables that benefit from burning-in, are ones used for high voltage power transmission, especially coaxial ones for HVDC. The voltage is slowly ramped up to maximum in one direction, then slowly ramped down and then ramped up to maximum in the opposite direction, then ramped down again and so on for a number of cycles. This is done to relieve any dielectric strain in the insulation that could lead to insulation breakdown.

[Malcolm G6ANZ]

So if I was to make up some phono to phono leads and advertise them as 'similar' to the Nordost cables and make no claims as to their sonic improvement could I make a killing?

[Beobloke]

The last time I did a major re-wire on some loudspeakers, the wire I used had been burned in for several years at 240Vac with varying loads of a random nature.

Obviously it sounds much less audiophile when I explain that this was because the wires used were the 2.5mm cores of our old garden mains extension lead, but still…

[barrymagrec]

Originally Posted by Beobloke

The last time I did a major re-wire on some loudspeakers, the wire I used had been burned in for several years at 240Vac with varying loads of a random nature.

Obviously it sounds much less audiophile when I explain that this was because the wires used were the 2.5mm cores of our old garden mains extension lead, but still…

Presumably you flushed out the 50Hz hum before using it?

[Radio Wrangler]

Originally Posted by Craig Sawyers

It basically generates pseudo random noise using a long repeat length tapped shift register.

"Shift Register Sequences" By Solomon W Golomb (pronounced 'Gollum')

Is the tome on creating maximal length sequences with analyses via modulo-2 arithmetic.

David

[mark_in_manc]

We used to use something called MLSSA years ago, for measuring electro-acoustic transfer functions - the deterministic (but random-like) 'out' signal could be deconvolved from the return signal to give a complex transfer function. It amazed me how the spectrum of the one-shorter-than-a-power-of-two MLS was entirely flat, but if you added a one or a zero on the end to give a nice round 1024 point sample length (for example) that was no longer true at all. At least that's how I remember it. I'm glad I don't need to know why that is any more!

[Radio Wrangler]

There was also stuff about how to use multiple bits to feed a DAC and to wind up with a close approximation to Gaussian white noise.... and at the very end were the masters' final exams... some of us had no choice but to go for full immersion. It left nightmares! doing bit by bit arithmetic and throwing away all the carries just seemed so wasteful.

From a point of having used it, our data error test sets used PRBS maximal length sequences as laid down by CCITT so that wasn't a problem. The receiver shift register was just forcibly flushed with current data and then looped with the feedback path once full so it could run independently as a comparison for later incoming data so errors could be counted. The flaw is that if the error rate is too high, the chances of an error corrupting the synchronisation brings the whole house of cards down.

The user knows that things are bad, but not just how bad.

David

[LPsmash]

£695 Graham Slee Phono Stage.

Vid shows the owner installing Audio Note Caps!

By all means I'm no engineer. But I still sense total delusional BS!

https://www.youtube.com/watch?v=hapvEH819kE&t=1s

S.

[Ted Kendall]

Never mind the tweaks - £695 for that?. Two op-amps and some bits?

[LPsmash]

Yup.

S.

[knobtwiddler]

Originally Posted by Ted Kendall

Never mind the tweaks - £695 for that?. Two op-amps and some bits?

Multi-layer PCBs are cheap as chips now. It is using a PCB that looks identical to the one in the 1973 scope that I have been servicing today. A phono preamp is a basic piece of electronics and the self-noise of the typical MM cart means that ciruitry improvements are likely buried under the cart's own resistive noise, but for £700 it ought to have dedicated power / ground / L / R signal planes, if even just for show.